Adding test coverage

ext/go-plugin/capabilities.go

@@ -11,168 +11,148 @@ import (
 
 //export GuestCapabilities
 func GuestCapabilities(pluginName, pluginType *C.char) *C.char {
-	r := vagrant.Response{}
+	r := &Response{}
-	p, err := getGuestCapsPlugin(pluginName, pluginType)
+	i, err := Plugins.PluginLookup(to_gs(pluginName), to_gs(pluginType))
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
+	}
+	p, ok := i.(*plugin.RemoteGuestCapabilities)
+	if !ok {
+		r.Error = errors.New("failed to load requested plugin")
+		return r.Dump()
 	}
 	r.Result, r.Error = p.GuestCapabilities.GuestCapabilities()
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export GuestCapability
 func GuestCapability(pluginName, pluginType, cname, cplatform, cargs, cmachine *C.char) *C.char {
-	r := vagrant.Response{}
+	r := &Response{}
-	p, err := getGuestCapsPlugin(pluginName, pluginType)
+	i, err := Plugins.PluginLookup(to_gs(pluginName), to_gs(pluginType))
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
-	machine, err := vagrant.LoadMachine(C.GoString(cmachine), nil)
+	p, ok := i.(*plugin.RemoteGuestCapabilities)
+	if !ok {
+		r.Error = errors.New("Failed to load requested plugin")
+		return r.Dump()
+	}
+	machine, err := vagrant.LoadMachine(to_gs(cmachine), nil)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	var args interface{}
-	err = json.Unmarshal([]byte(C.GoString(cargs)), &args)
+	err = json.Unmarshal([]byte(to_gs(cargs)), &args)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	cap := &vagrant.SystemCapability{
-		Name:     C.GoString(cname),
+		Name:     to_gs(cname),
-		Platform: C.GoString(cplatform)}
+		Platform: to_gs(cplatform)}
 	r.Result, r.Error = p.GuestCapabilities.GuestCapability(cap, args, machine)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export HostCapabilities
 func HostCapabilities(pluginName, pluginType *C.char) *C.char {
-	r := vagrant.Response{}
+	r := &Response{}
-	p, err := getHostCapsPlugin(pluginName, pluginType)
+	i, err := Plugins.PluginLookup(to_gs(pluginName), to_gs(pluginType))
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
+	p, ok := i.(*plugin.RemoteHostCapabilities)
+	if !ok {
+		r.Error = errors.New("Failed to load requested plugin")
+		return r.Dump()
+	}
+
 	r.Result, r.Error = p.HostCapabilities.HostCapabilities()
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export HostCapability
 func HostCapability(pluginName, pluginType, cname, cplatform, cargs, cenv *C.char) *C.char {
-	r := vagrant.Response{}
+	r := &Response{}
-	p, err := getHostCapsPlugin(pluginName, pluginType)
+	i, err := Plugins.PluginLookup(to_gs(pluginName), to_gs(pluginType))
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
-	env, err := vagrant.LoadEnvironment(C.GoString(cenv), nil)
+	p, ok := i.(*plugin.RemoteHostCapabilities)
+	if !ok {
+		r.Error = errors.New("Failed to load requested plugin")
+		return r.Dump()
+	}
+
+	env, err := vagrant.LoadEnvironment(to_gs(cenv), nil)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	var args interface{}
-	err = json.Unmarshal([]byte(C.GoString(cargs)), &args)
+	err = json.Unmarshal([]byte(to_gs(cargs)), &args)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	cap := &vagrant.SystemCapability{
-		Name:     C.GoString(cname),
+		Name:     to_gs(cname),
-		Platform: C.GoString(cplatform)}
+		Platform: to_gs(cplatform)}
 	r.Result, r.Error = p.HostCapabilities.HostCapability(cap, args, env)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export ProviderCapabilities
 func ProviderCapabilities(pluginName, pluginType *C.char) *C.char {
-	r := vagrant.Response{}
+	r := &Response{}
-	p, err := getProviderCapsPlugin(pluginName, pluginType)
+	i, err := Plugins.PluginLookup(to_gs(pluginName), to_gs(pluginType))
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
+	p, ok := i.(*plugin.RemoteProviderCapabilities)
+	if !ok {
+		r.Error = errors.New("Failed to load requested plugin")
+		return r.Dump()
+	}
+
 	r.Result, r.Error = p.ProviderCapabilities.ProviderCapabilities()
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export ProviderCapability
 func ProviderCapability(pluginName, pluginType, cname, cprovider, cargs, cmach *C.char) *C.char {
-	r := vagrant.Response{}
+	r := &Response{}
-	p, err := getProviderCapsPlugin(pluginName, pluginType)
+	i, err := Plugins.PluginLookup(to_gs(pluginName), to_gs(pluginType))
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
-	m, err := vagrant.LoadMachine(C.GoString(cmach), nil)
+	p, ok := i.(*plugin.RemoteProviderCapabilities)
+	if !ok {
+		r.Error = errors.New("Failed to load requested plugin")
+		return r.Dump()
+	}
+
+	m, err := vagrant.LoadMachine(to_gs(cmach), nil)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	var args interface{}
-	err = json.Unmarshal([]byte(C.GoString(cargs)), &args)
+	err = json.Unmarshal([]byte(to_gs(cargs)), &args)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	cap := &vagrant.ProviderCapability{
-		Name:     C.GoString(cname),
+		Name:     to_gs(cname),
-		Provider: C.GoString(cprovider)}
+		Provider: to_gs(cprovider)}
 	r.Result, r.Error = p.ProviderCapabilities.ProviderCapability(cap, args, m)
-	return C.CString(r.Dump())
+	return r.Dump()
-}
-
-func getProviderCapsPlugin(pluginName, pluginType *C.char) (c *plugin.RemoteProviderCapabilities, err error) {
-	pname := C.GoString(pluginName)
-	ptype := C.GoString(pluginType)
-
-	if ptype == "provider" {
-		p, ok := Plugins.Providers[pname]
-		if ok {
-			c = &plugin.RemoteProviderCapabilities{
-				Client:               p.Client,
-				ProviderCapabilities: p.Provider}
-		}
-	}
-	if c == nil {
-		err = errors.New("Failed to locate requested plugin")
-	}
-	return
-}
-
-func getGuestCapsPlugin(pluginName, pluginType *C.char) (c *plugin.RemoteGuestCapabilities, err error) {
-	pname := C.GoString(pluginName)
-	ptype := C.GoString(pluginType)
-
-	if ptype == "provider" {
-		p, ok := Plugins.Providers[pname]
-		if ok {
-			c = &plugin.RemoteGuestCapabilities{
-				Client:            p.Client,
-				GuestCapabilities: p.Provider}
-		}
-	}
-	if c == nil {
-		err = errors.New("Failed to locate requested plugin")
-	}
-	return
-}
-
-func getHostCapsPlugin(pluginName, pluginType *C.char) (c *plugin.RemoteHostCapabilities, err error) {
-	pname := C.GoString(pluginName)
-	ptype := C.GoString(pluginType)
-
-	if ptype == "provider" {
-		p, ok := Plugins.Providers[pname]
-		if ok {
-			c = &plugin.RemoteHostCapabilities{
-				Client:           p.Client,
-				HostCapabilities: p.Provider}
-		}
-	}
-	if c == nil {
-		err = errors.New("Failed to locate requested plugin")
-	}
-	return
 }

ext/go-plugin/capabilities_test.go

@@ -0,0 +1,414 @@
+package main
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/hashicorp/go-plugin"
+	vplugin "github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin"
+)
+
+func TestCapabilities_GuestCapabilities(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &vplugin.GuestCapabilitiesPlugin{Impl: &vplugin.MockGuestCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.GuestCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteGuestCapabilities{
+		GuestCapabilities: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	result := GuestCapabilities(nil, nil)
+	resp, err := LoadResponse(result)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	caps, ok := resp.Result.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	cap, ok := caps[0].(map[string]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", caps[0])
+	}
+
+	if cap["name"] != "test_cap" {
+		t.Errorf("%s != test_cap", cap["name"])
+	}
+	if cap["platform"] != "testOS" {
+		t.Errorf("%s != testOS", cap["platform"])
+	}
+}
+
+func TestCapabilities_GuestCapability(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &vplugin.GuestCapabilitiesPlugin{Impl: &vplugin.MockGuestCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.GuestCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteGuestCapabilities{
+		GuestCapabilities: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	a, err := json.Marshal([]string{"test_arg", "other_arg"})
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	args := string(a)
+	result := GuestCapability(nil, nil, to_cs("test_cap"), to_cs("test_platform"), to_cs(args), to_cs("{}"))
+	resp, err := LoadResponse(result)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	r, ok := resp.Result.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	if r[0] != "test_cap" {
+		t.Errorf("%s != test_cap", r[0])
+	}
+	if r[1] != "test_arg" {
+		t.Errorf("%s != test_arg", r[1])
+	}
+}
+
+func TestCapabilities_GuestCapability_noargs(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &vplugin.GuestCapabilitiesPlugin{Impl: &vplugin.MockGuestCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.GuestCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteGuestCapabilities{
+		GuestCapabilities: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	result := GuestCapability(nil, nil, to_cs("test_cap"), to_cs("test_platform"), to_cs("null"), to_cs("{}"))
+	resp, err := LoadResponse(result)
+	if err != nil {
+		t.Fatalf("err: %s - %s", err, to_gs(result))
+	}
+
+	r, ok := resp.Result.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	if len(r) != 1 {
+		t.Errorf("%d != 1", len(r))
+	}
+	if r[0] != "test_cap" {
+		t.Errorf("%s != test_cap", r[0])
+	}
+}
+
+func TestCapabilities_HostCapabilities(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &vplugin.HostCapabilitiesPlugin{Impl: &vplugin.MockHostCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.HostCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteHostCapabilities{
+		HostCapabilities: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	result := HostCapabilities(nil, nil)
+	resp, err := LoadResponse(result)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	caps, ok := resp.Result.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	cap, ok := caps[0].(map[string]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", caps[0])
+	}
+
+	if cap["name"] != "test_cap" {
+		t.Errorf("%s != test_cap", cap["name"])
+	}
+	if cap["platform"] != "testOS" {
+		t.Errorf("%s != testOS", cap["platform"])
+	}
+}
+
+func TestCapabilities_HostCapability(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &vplugin.HostCapabilitiesPlugin{Impl: &vplugin.MockHostCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.HostCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteHostCapabilities{
+		HostCapabilities: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	a, err := json.Marshal([]string{"test_arg", "other_arg"})
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	args := string(a)
+	result := HostCapability(nil, nil, to_cs("test_cap"), to_cs("test_platform"), to_cs(args), to_cs("{}"))
+	resp, err := LoadResponse(result)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	r, ok := resp.Result.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	if r[0] != "test_cap" {
+		t.Errorf("%s != test_cap", r[0])
+	}
+	if r[1] != "test_arg" {
+		t.Errorf("%s != test_arg", r[1])
+	}
+}
+
+func TestCapabilities_HostCapability_noargs(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &vplugin.HostCapabilitiesPlugin{Impl: &vplugin.MockHostCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.HostCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteHostCapabilities{
+		HostCapabilities: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	result := HostCapability(nil, nil, to_cs("test_cap"), to_cs("test_platform"), to_cs("null"), to_cs("{}"))
+	resp, err := LoadResponse(result)
+	if err != nil {
+		t.Fatalf("err: %s - %s", err, to_gs(result))
+	}
+
+	r, ok := resp.Result.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	if len(r) != 1 {
+		t.Errorf("%d != 1", len(r))
+	}
+	if r[0] != "test_cap" {
+		t.Errorf("%s != test_cap", r[0])
+	}
+}
+
+func TestCapabilities_ProviderCapabilities(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &vplugin.ProviderCapabilitiesPlugin{Impl: &vplugin.MockProviderCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.ProviderCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteProviderCapabilities{
+		ProviderCapabilities: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	result := ProviderCapabilities(nil, nil)
+	resp, err := LoadResponse(result)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	caps, ok := resp.Result.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	cap, ok := caps[0].(map[string]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", caps[0])
+	}
+
+	if cap["name"] != "test_cap" {
+		t.Errorf("%s != test_cap", cap["name"])
+	}
+	if cap["provider"] != "testProvider" {
+		t.Errorf("%s != testProvider", cap["provider"])
+	}
+}
+
+func TestCapabilities_ProviderCapability(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &vplugin.ProviderCapabilitiesPlugin{Impl: &vplugin.MockProviderCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.ProviderCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteProviderCapabilities{
+		ProviderCapabilities: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	a, err := json.Marshal([]string{"test_arg", "other_arg"})
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	args := string(a)
+	result := ProviderCapability(nil, nil, to_cs("test_cap"), to_cs("test_provider"), to_cs(args), to_cs("{}"))
+	resp, err := LoadResponse(result)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	r, ok := resp.Result.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	if r[0] != "test_cap" {
+		t.Errorf("%s != test_cap", r[0])
+	}
+	if r[1] != "test_arg" {
+		t.Errorf("%s != test_arg", r[1])
+	}
+}
+
+func TestCapabilities_ProviderCapability_noargs(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &vplugin.ProviderCapabilitiesPlugin{Impl: &vplugin.MockProviderCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.ProviderCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteProviderCapabilities{
+		ProviderCapabilities: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	result := ProviderCapability(nil, nil, to_cs("test_cap"), to_cs("test_provider"), to_cs("null"), to_cs("{}"))
+	resp, err := LoadResponse(result)
+	if err != nil {
+		t.Fatalf("err: %s - %s", err, to_gs(result))
+	}
+
+	r, ok := resp.Result.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	if len(r) != 1 {
+		t.Errorf("%d != 1", len(r))
+	}
+	if r[0] != "test_cap" {
+		t.Errorf("%s != test_cap", r[0])
+	}
+}

ext/go-plugin/config.go

@@ -4,7 +4,6 @@ import (
 	"C"
 	"encoding/json"
 	"errors"
-	"fmt"
 
 	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant"
 	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin"
@@ -12,87 +11,87 @@ import (
 
 //export ConfigLoad
 func ConfigLoad(pluginName, pluginType, data *C.char) *C.char {
-	r := vagrant.Response{}
+	r := &Response{}
-	p, err := getConfigPlugin(pluginName, pluginType)
+	i, err := Plugins.PluginLookup(to_gs(pluginName), to_gs(pluginType))
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
+	}
+	p, ok := i.(*plugin.RemoteConfig)
+	if !ok {
+		r.Error = errors.New("failed to load requested plugin")
+		return r.Dump()
 	}
 	var cdata map[string]interface{}
-	r.Error = json.Unmarshal([]byte(C.GoString(data)), &cdata)
+	r.Error = json.Unmarshal([]byte(to_gs(data)), &cdata)
 	if r.Error != nil {
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	r.Result, r.Error = p.Config.ConfigLoad(cdata)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export ConfigAttributes
 func ConfigAttributes(pluginName, pluginType *C.char) *C.char {
-	r := vagrant.Response{}
+	r := &Response{}
-	p, err := getConfigPlugin(pluginName, pluginType)
+	i, err := Plugins.PluginLookup(to_gs(pluginName), to_gs(pluginType))
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
+	}
+	p, ok := i.(*plugin.RemoteConfig)
+	if !ok {
+		r.Error = errors.New("failed to load requested plugin")
+		return r.Dump()
 	}
 	r.Result, r.Error = p.Config.ConfigAttributes()
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export ConfigValidate
 func ConfigValidate(pluginName, pluginType, data, machData *C.char) *C.char {
 	var m *vagrant.Machine
-	r := vagrant.Response{}
+	r := &Response{}
-	p, err := getConfigPlugin(pluginName, pluginType)
+	i, err := Plugins.PluginLookup(to_gs(pluginName), to_gs(pluginType))
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
+	}
+	p, ok := i.(*plugin.RemoteConfig)
+	if !ok {
+		r.Error = errors.New("failed to load requested plugin")
+		return r.Dump()
 	}
 	var cdata map[string]interface{}
-	r.Error = json.Unmarshal([]byte(C.GoString(data)), &cdata)
+	r.Error = json.Unmarshal([]byte(to_gs(data)), &cdata)
 	if r.Error != nil {
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
-	m, r.Error = vagrant.LoadMachine(C.GoString(machData), nil)
+	m, r.Error = vagrant.LoadMachine(to_gs(machData), nil)
 	if r.Error != nil {
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	r.Result, r.Error = p.Config.ConfigValidate(cdata, m)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export ConfigFinalize
 func ConfigFinalize(pluginName, pluginType, data *C.char) *C.char {
-	r := vagrant.Response{}
+	r := &Response{}
-	p, err := getConfigPlugin(pluginName, pluginType)
+	i, err := Plugins.PluginLookup(to_gs(pluginName), to_gs(pluginType))
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
+	}
+	p, ok := i.(*plugin.RemoteConfig)
+	if !ok {
+		r.Error = errors.New("failed to load requested plugin")
+		return r.Dump()
 	}
 	var cdata map[string]interface{}
-	r.Error = json.Unmarshal([]byte(C.GoString(data)), &cdata)
+	r.Error = json.Unmarshal([]byte(to_gs(data)), &cdata)
 	if r.Error == nil {
-		println("FINALIZE HAS VALID CONFIG")
 		r.Result, r.Error = p.Config.ConfigFinalize(cdata)
 	}
-	fmt.Printf("Full result: %s\n", r.Dump())
+	return r.Dump()
-	return C.CString(r.Dump())
-}
-
-func getConfigPlugin(pluginName, pluginType *C.char) (c *plugin.RemoteConfig, err error) {
-	pname := C.GoString(pluginName)
-	ptype := C.GoString(pluginType)
-
-	if ptype == "provider" {
-		p, ok := Plugins.Providers[pname]
-		if ok {
-			c = &plugin.RemoteConfig{
-				Client: p.Client,
-				Config: p.Provider}
-		}
-	}
-	if c == nil {
-		err = errors.New("Failed to locate requested plugin")
-	}
-	return
 }

ext/go-plugin/config_test.go

@@ -0,0 +1,203 @@
+package main
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/hashicorp/go-plugin"
+	vplugin "github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin"
+)
+
+func TestConfig_Load(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"config": &vplugin.ConfigPlugin{Impl: &vplugin.MockConfig{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("config")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.Config)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteConfig{
+		Config: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	data := map[string]string{"test_key": "custom_val"}
+	s, err := json.Marshal(data)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	result := ConfigLoad(nil, nil, to_cs(string(s)))
+	resp, err := LoadResponse(result)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	if resp.Error != nil {
+		t.Fatalf("err: %s", resp.Error)
+	}
+	config, ok := resp.Result.(map[string]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	if config["test_key"] != "test_val" {
+		t.Errorf("%s != test_val", config["test_key"])
+	}
+	if config["sent_key"] != "custom_val" {
+		t.Errorf("%s != custom_val", config["sent_key"])
+	}
+}
+
+func TestConfig_Attributes(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"config": &vplugin.ConfigPlugin{Impl: &vplugin.MockConfig{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("config")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.Config)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteConfig{
+		Config: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	result := ConfigAttributes(nil, nil)
+	resp, err := LoadResponse(result)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	if resp.Error != nil {
+		t.Fatalf("err: %s", resp.Error)
+	}
+	attrs, ok := resp.Result.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	if len(attrs) != 2 {
+		t.Fatalf("%d != 2", len(attrs))
+	}
+	if attrs[0] != "fubar" {
+		t.Errorf("%s != fubar", attrs[0])
+	}
+	if attrs[1] != "foobar" {
+		t.Errorf("%s != foobar", attrs[1])
+	}
+}
+
+func TestConfig_Validate(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"config": &vplugin.ConfigPlugin{Impl: &vplugin.MockConfig{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("config")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.Config)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteConfig{
+		Config: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	data := map[string]string{"test_key": "custom_val"}
+	s, err := json.Marshal(data)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	result := ConfigValidate(nil, nil, to_cs(string(s)), to_cs("{}"))
+	resp, err := LoadResponse(result)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	if resp.Error != nil {
+		t.Fatalf("err: %s", resp.Error)
+	}
+	errs, ok := resp.Result.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	if len(errs) != 1 {
+		t.Fatalf("%d != 1", len(errs))
+	}
+	if errs[0] != "test error" {
+		t.Errorf("%s != test error", errs[0])
+	}
+}
+
+func TestConfig_Finalize(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"config": &vplugin.ConfigPlugin{Impl: &vplugin.MockConfig{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("config")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.Config)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteConfig{
+		Config: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	data := map[string]string{"test_key": "custom_val"}
+	s, err := json.Marshal(data)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	result := ConfigFinalize(nil, nil, to_cs(string(s)))
+	resp, err := LoadResponse(result)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	if resp.Error != nil {
+		t.Fatalf("err: %s", resp.Error)
+	}
+	config, ok := resp.Result.(map[string]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	if config["test_key"] != "custom_val-updated" {
+		t.Errorf("%s != custom_val-updated", config["test_key"])
+	}
+}

ext/go-plugin/go-plugin.go

@@ -14,7 +14,7 @@ var Plugins *plugin.VagrantPlugin
 
 //export Setup
 func Setup(enableLogger, timestamps bool, logLevel *C.char) bool {
-	lvl := C.GoString(logLevel)
+	lvl := to_gs(logLevel)
 	lopts := &hclog.LoggerOptions{Name: "vagrant"}
 	if enableLogger {
 		lopts.Output = os.Stderr
@@ -32,10 +32,7 @@ func Setup(enableLogger, timestamps bool, logLevel *C.char) bool {
 		return false
 	}
 
-	Plugins = &plugin.VagrantPlugin{
+	Plugins = plugin.VagrantPluginInit()
-		PluginDirectories: []string{},
-		Providers:         map[string]*plugin.RemoteProvider{},
-		Logger:            vagrant.DefaultLogger().Named("go-plugin")}
 	return true
 }
 
@@ -46,7 +43,7 @@ func LoadPlugins(plgpath *C.char) bool {
 		return false
 	}
 
-	p := C.GoString(plgpath)
+	p := to_gs(plgpath)
 	err := Plugins.LoadPlugins(p)
 	if err != nil {
 		Plugins.Logger.Error("failed loading plugins",
@@ -86,3 +83,13 @@ func Teardown() {
 
 // stub required for build
 func main() {}
+
+// helper to convert c string to go string
+func to_gs(s *C.char) string {
+	return C.GoString(s)
+}
+
+// helper to convert go string to c string
+func to_cs(s string) *C.char {
+	return C.CString(s)
+}

ext/go-plugin/provider.go

@@ -4,7 +4,6 @@ import (
 	"C"
 	"encoding/json"
 	"errors"
-	"fmt"
 
 	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant"
 	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin"
@@ -13,169 +12,176 @@ import (
 //export ListProviders
 func ListProviders() *C.char {
 	list := map[string]interface{}{}
-	r := vagrant.Response{Result: list}
+	r := &Response{Result: list}
 	if Plugins == nil {
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	for n, p := range Plugins.Providers {
 		list[n] = p.Provider.Info()
 	}
 	r.Result = list
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export ProviderAction
 func ProviderAction(providerName *C.char, actionName *C.char, machData *C.char) *C.char {
-	var p *plugin.RemoteProvider
+	r := &Response{}
-	var m *vagrant.Machine
+	i, err := Plugins.PluginLookup(to_gs(providerName), "provider")
-
+	if err != nil {
-	r := vagrant.Response{}
+		r.Error = err
-	p, r.Error = getProvider(providerName)
+		return r.Dump()
-	if r.Error != nil {
-		return C.CString(r.Dump())
 	}
-	m, r.Error = vagrant.LoadMachine(C.GoString(machData), nil)
+	p, ok := i.(*plugin.RemoteProvider)
-	if r.Error != nil {
+	if !ok {
-		return C.CString(r.Dump())
+		r.Error = errors.New("failed to load requested plugin")
+		return r.Dump()
 	}
-	aName := C.GoString(actionName)
+	m, err := vagrant.LoadMachine(to_gs(machData), nil)
+	if err != nil {
+		r.Error = err
+		return r.Dump()
+	}
+	aName := to_gs(actionName)
 	r.Result, r.Error = p.Provider.Action(aName, m)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export ProviderIsInstalled
 func ProviderIsInstalled(providerName *C.char, machData *C.char) *C.char {
-	var p *plugin.RemoteProvider
+	r := &Response{}
-	var m *vagrant.Machine
+	i, err := Plugins.PluginLookup(to_gs(providerName), "provider")
-
+	if err != nil {
-	r := vagrant.Response{}
+		r.Error = err
-	p, r.Error = getProvider(providerName)
+		return r.Dump()
-	if r.Error != nil {
-		return C.CString(r.Dump())
 	}
-	m, r.Error = vagrant.LoadMachine(C.GoString(machData), nil)
+	p, ok := i.(*plugin.RemoteProvider)
-	if r.Error != nil {
+	if !ok {
-		return C.CString(r.Dump())
+		r.Error = errors.New("failed to load requested plugin")
+		return r.Dump()
+	}
+	m, err := vagrant.LoadMachine(to_gs(machData), nil)
+	if err != nil {
+		r.Error = err
+		return r.Dump()
 	}
 	r.Result, r.Error = p.Provider.IsInstalled(m)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export ProviderIsUsable
 func ProviderIsUsable(providerName *C.char, machData *C.char) *C.char {
-	var p *plugin.RemoteProvider
+	r := &Response{}
-	var m *vagrant.Machine
+	i, err := Plugins.PluginLookup(to_gs(providerName), "provider")
-
+	if err != nil {
-	r := vagrant.Response{}
+		r.Error = err
-	p, r.Error = getProvider(providerName)
+		return r.Dump()
-	if r.Error != nil {
-		return C.CString(r.Dump())
 	}
-	m, r.Error = vagrant.LoadMachine(C.GoString(machData), nil)
+	p, ok := i.(*plugin.RemoteProvider)
-	if r.Error != nil {
+	if !ok {
-		return C.CString(r.Dump())
+		r.Error = errors.New("failed to load requested plugin")
+		return r.Dump()
+	}
+
+	m, err := vagrant.LoadMachine(to_gs(machData), nil)
+	if err != nil {
+		r.Error = err
+		return r.Dump()
 	}
 	r.Result, r.Error = p.Provider.IsUsable(m)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export ProviderMachineIdChanged
 func ProviderMachineIdChanged(providerName *C.char, machData *C.char) *C.char {
-	var p *plugin.RemoteProvider
+	r := &Response{}
-	var m *vagrant.Machine
+	i, err := Plugins.PluginLookup(to_gs(providerName), "provider")
-
+	if err != nil {
-	r := vagrant.Response{}
+		r.Error = err
-	p, r.Error = getProvider(providerName)
+		return r.Dump()
-	if r.Error != nil {
-		return C.CString(r.Dump())
 	}
-	m, r.Error = vagrant.LoadMachine(C.GoString(machData), nil)
+	p, ok := i.(*plugin.RemoteProvider)
-	if r.Error != nil {
+	if !ok {
-		return C.CString(r.Dump())
+		r.Error = errors.New("failed to load requested plugin")
+		return r.Dump()
+	}
+	m, err := vagrant.LoadMachine(to_gs(machData), nil)
+	if err != nil {
+		r.Error = err
+		return r.Dump()
 	}
 	r.Error = p.Provider.MachineIdChanged(m)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export ProviderRunAction
 func ProviderRunAction(providerName *C.char, actName *C.char, runData *C.char, machData *C.char) *C.char {
-	var p *plugin.RemoteProvider
+	r := &Response{}
-	var m *vagrant.Machine
+	i, err := Plugins.PluginLookup(to_gs(providerName), "provider")
-
+	if err != nil {
-	r := vagrant.Response{}
+		r.Error = err
-	p, r.Error = getProvider(providerName)
+		return r.Dump()
-	if r.Error != nil {
-		return C.CString(r.Dump())
 	}
-	m, r.Error = vagrant.LoadMachine(C.GoString(machData), nil)
+	p, ok := i.(*plugin.RemoteProvider)
-	if r.Error != nil {
+	if !ok {
-		return C.CString(r.Dump())
+		r.Error = errors.New("failed to load requested plugin")
+		return r.Dump()
+	}
+	m, err := vagrant.LoadMachine(to_gs(machData), nil)
+	if err != nil {
+		r.Error = err
+		return r.Dump()
+	}
+	aName := to_gs(actName)
+	var rData interface{}
+	err = json.Unmarshal([]byte(to_gs(runData)), &rData)
+	if err != nil {
+		r.Error = err
+		return r.Dump()
 	}
-	aName := C.GoString(actName)
-	rData := C.GoString(runData)
 	r.Result, r.Error = p.Provider.RunAction(aName, rData, m)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export ProviderSshInfo
 func ProviderSshInfo(providerName *C.char, machData *C.char) *C.char {
-	var p *plugin.RemoteProvider
+	r := &Response{}
-	var m *vagrant.Machine
+	i, err := Plugins.PluginLookup(to_gs(providerName), "provider")
-
+	if err != nil {
-	r := vagrant.Response{}
+		r.Error = err
-	p, r.Error = getProvider(providerName)
+		return r.Dump()
-	if r.Error != nil {
-		return C.CString(r.Dump())
 	}
-	m, r.Error = vagrant.LoadMachine(C.GoString(machData), nil)
+	p, ok := i.(*plugin.RemoteProvider)
-	if r.Error != nil {
+	if !ok {
-		return C.CString(r.Dump())
+		r.Error = errors.New("failed to load requested plugin")
+		return r.Dump()
+	}
+	m, err := vagrant.LoadMachine(to_gs(machData), nil)
+	if err != nil {
+		r.Error = err
+		return r.Dump()
 	}
 	r.Result, r.Error = p.Provider.SshInfo(m)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export ProviderState
 func ProviderState(providerName *C.char, machData *C.char) *C.char {
-	var p *plugin.RemoteProvider
+	r := &Response{}
-	var m *vagrant.Machine
+	i, err := Plugins.PluginLookup(to_gs(providerName), "provider")
-
+	if err != nil {
-	r := vagrant.Response{}
+		r.Error = err
-	p, r.Error = getProvider(providerName)
+		return r.Dump()
-	if r.Error != nil {
-		return C.CString(r.Dump())
 	}
-	m, r.Error = vagrant.LoadMachine(C.GoString(machData), nil)
+	p, ok := i.(*plugin.RemoteProvider)
-	if r.Error != nil {
+	if !ok {
-		return C.CString(r.Dump())
+		r.Error = errors.New("failed to load requested plugin")
+		return r.Dump()
+	}
+	m, err := vagrant.LoadMachine(to_gs(machData), nil)
+	if err != nil {
+		r.Error = err
+		return r.Dump()
 	}
 	r.Result, r.Error = p.Provider.State(m)
-	return C.CString(r.Dump())
+	return r.Dump()
-}
-
-func getProvider(pName *C.char) (*plugin.RemoteProvider, error) {
-	providerName := C.GoString(pName)
-	p, ok := Plugins.Providers[providerName]
-	if !ok {
-		Plugins.Logger.Error("error fetching plugin", "type", "provider",
-			"name", providerName, "reason", "not found")
-		return nil, errors.New(fmt.Sprintf(
-			"failed to locate provider plugin `%s`", providerName))
-	}
-	return p, nil
-}
-
-// Loads the machine data JSON string to ensure that it is
-// valid JSON. Returns the converted GoString to be used
-// internally
-func validateMachine(machineData *C.char) (string, error) {
-	mData := C.GoString(machineData)
-	Plugins.Logger.Debug("received machine info", "data", mData)
-	err := json.Unmarshal([]byte(mData), &vagrant.Machine{})
-	if err != nil {
-		fmt.Printf("Error: %s\n", err)
-		err = errors.New(fmt.Sprintf(
-			"failed to load vagrant environment information - %s", err))
-	}
-	return mData, err
 }

ext/go-plugin/provider_test.go

@@ -0,0 +1,320 @@
+package main
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/hashicorp/go-plugin"
+	vplugin "github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin"
+)
+
+func TestProvider_ListProviders(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &vplugin.ProviderPlugin{Impl: &vplugin.MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteProvider{
+		Provider: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.Providers[impl.Name()] = p
+
+	result := ListProviders()
+	resp, err := LoadResponse(result)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	if resp.Error != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	r, ok := resp.Result.(map[string]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	if r["mock_provider"] == nil {
+		t.Fatalf("bad result")
+	}
+
+	i, ok := r["mock_provider"].(map[string]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", r["mock_provider"])
+	}
+
+	if i["description"] != "Custom" {
+		t.Errorf("%s != Custom", i["description"])
+	}
+	if i["priority"] != 10.0 {
+		t.Errorf("%d != 10", i["priority"])
+	}
+}
+
+func TestProvider_ProviderAction(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &vplugin.ProviderPlugin{Impl: &vplugin.MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteProvider{
+		Provider: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	result := ProviderAction(nil, to_cs("valid"), to_cs("{}"))
+	resp, err := LoadResponse(result)
+	if resp.Error != nil {
+		t.Fatalf("err: %s", resp.Error)
+	}
+	r := resp.Result.([]interface{})
+	if r[0] != "self::DoTask" {
+		t.Errorf("%s != self::DoTask", r[0])
+	}
+}
+
+func TestProvider_ProviderIsInstalled(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &vplugin.ProviderPlugin{Impl: &vplugin.MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteProvider{
+		Provider: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	result := ProviderIsInstalled(nil, to_cs("{}"))
+	resp, err := LoadResponse(result)
+	if resp.Error != nil {
+		t.Fatalf("err: %s", resp.Error)
+	}
+
+	if !resp.Result.(bool) {
+		t.Errorf("bad result")
+	}
+}
+
+func TestProvider_ProviderIsUsable(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &vplugin.ProviderPlugin{Impl: &vplugin.MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteProvider{
+		Provider: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	result := ProviderIsUsable(nil, to_cs("{}"))
+	resp, err := LoadResponse(result)
+	if resp.Error != nil {
+		t.Fatalf("err: %s", resp.Error)
+	}
+
+	if !resp.Result.(bool) {
+		t.Errorf("bad result")
+	}
+}
+
+func TestProvider_ProviderMachineIdChanged(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &vplugin.ProviderPlugin{Impl: &vplugin.MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteProvider{
+		Provider: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	result := ProviderMachineIdChanged(nil, to_cs("{}"))
+	resp, err := LoadResponse(result)
+	if resp.Error != nil {
+		t.Fatalf("err: %s", resp.Error)
+	}
+}
+
+func TestProvider_ProviderRunAction(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &vplugin.ProviderPlugin{Impl: &vplugin.MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteProvider{
+		Provider: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	a, err := json.Marshal([]string{"test_arg"})
+	args := string(a)
+
+	result := ProviderRunAction(nil, to_cs("valid"), to_cs(args), to_cs("{}"))
+	resp, err := LoadResponse(result)
+	if resp.Error != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	r, ok := resp.Result.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+	if r[0] != "valid" {
+		t.Errorf("%s != valid", r[0])
+	}
+	if r[1] != "test_arg" {
+		t.Errorf("%s != test_arg", r[1])
+	}
+}
+
+func TestProvider_ProviderSshInfo(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &vplugin.ProviderPlugin{Impl: &vplugin.MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteProvider{
+		Provider: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	result := ProviderSshInfo(nil, to_cs("{}"))
+	resp, err := LoadResponse(result)
+	if resp.Error != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	r, ok := resp.Result.(map[string]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	if r["host"] != "localhost" {
+		t.Errorf("%s != localhost", r["host"])
+	}
+	if r["port"] != 2222.0 {
+		t.Errorf("%d != 2222", r["port"])
+	}
+}
+
+func TestProvider_ProviderState(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &vplugin.ProviderPlugin{Impl: &vplugin.MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(vplugin.Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	p := &vplugin.RemoteProvider{
+		Provider: impl}
+	Plugins = vplugin.VagrantPluginInit()
+	Plugins.PluginLookup = func(_, _ string) (r interface{}, err error) {
+		r = p
+		return
+	}
+
+	result := ProviderState(nil, to_cs("{}"))
+	resp, err := LoadResponse(result)
+	if resp.Error != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	r, ok := resp.Result.(map[string]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", resp.Result)
+	}
+
+	if r["id"] != "default" {
+		t.Errorf("%s != default", r["id"])
+	}
+	if r["short_description"] != "running" {
+		t.Errorf("%s != running", r["short_description"])
+	}
+}

ext/go-plugin/response.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"C"
+	"encoding/json"
+	"errors"
+	"fmt"
+)
+
+type Response struct {
+	Error  error       `json:"error"`
+	Result interface{} `json:"result"`
+}
+
+// Serialize the response into a JSON C string
+func (r *Response) Dump() *C.char {
+	tmp := map[string]interface{}{}
+	if r.Error != nil {
+		tmp["error"] = r.Error.Error()
+	} else {
+		tmp["error"] = nil
+	}
+	tmp["result"] = r.Result
+	result, err := json.Marshal(tmp)
+	if err != nil {
+		return to_cs(fmt.Sprintf(`{"error": "failed to encode response - %s"}`, err))
+	}
+	return to_cs(string(result[:]))
+}
+
+// Load a new response from a JSON C string
+func LoadResponse(s *C.char) (r *Response, err error) {
+	tmp := map[string]interface{}{}
+	st := []byte(to_gs(s))
+	r = &Response{}
+	err = json.Unmarshal(st, &tmp)
+	if tmp["error"] != nil {
+		e, ok := tmp["error"].(string)
+		if !ok {
+			err = errors.New(
+				fmt.Sprintf("cannot load error content - %s", tmp["error"]))
+			return
+		}
+		r.Error = errors.New(e)
+	}
+	r.Result = tmp["result"]
+	return
+}

ext/go-plugin/synced_folder.go

@@ -12,135 +12,135 @@ import (
 //export ListSyncedFolders
 func ListSyncedFolders() *C.char {
 	list := map[string]interface{}{}
-	r := vagrant.Response{Result: list}
+	r := &Response{Result: list}
 	if Plugins == nil {
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	for n, p := range Plugins.SyncedFolders {
 		list[n] = p.SyncedFolder.Info()
 	}
 	r.Result = list
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export SyncedFolderCleanup
 func SyncedFolderCleanup(pluginName, machine, opts *C.char) *C.char {
-	r := vagrant.Response{}
+	r := &Response{}
 	p, err := getSyncedFolderPlugin(pluginName)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	m, err := vagrant.LoadMachine(C.GoString(machine), nil)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	var o vagrant.FolderOptions
 	r.Error = json.Unmarshal([]byte(C.GoString(opts)), &o)
 	if r.Error != nil {
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
-	r.Error = p.SyncedFolder.Cleanup(m, &o)
+	r.Error = p.SyncedFolder.Cleanup(m, o)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export SyncedFolderDisable
 func SyncedFolderDisable(pluginName, machine, folders, opts *C.char) *C.char {
-	r := vagrant.Response{}
+	r := &Response{}
 	p, err := getSyncedFolderPlugin(pluginName)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	m, err := vagrant.LoadMachine(C.GoString(machine), nil)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	var f vagrant.FolderList
 	r.Error = json.Unmarshal([]byte(C.GoString(folders)), &f)
 	if r.Error != nil {
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	var o vagrant.FolderOptions
 	r.Error = json.Unmarshal([]byte(C.GoString(opts)), &o)
 	if r.Error != nil {
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
-	r.Error = p.SyncedFolder.Disable(m, &f, &o)
+	r.Error = p.SyncedFolder.Disable(m, f, o)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export SyncedFolderEnable
 func SyncedFolderEnable(pluginName, machine, folders, opts *C.char) *C.char {
-	r := vagrant.Response{}
+	r := &Response{}
 	p, err := getSyncedFolderPlugin(pluginName)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	m, err := vagrant.LoadMachine(C.GoString(machine), nil)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	var f vagrant.FolderList
 	r.Error = json.Unmarshal([]byte(C.GoString(folders)), &f)
 	if r.Error != nil {
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	var o vagrant.FolderOptions
 	r.Error = json.Unmarshal([]byte(C.GoString(opts)), &o)
 	if r.Error != nil {
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
-	r.Error = p.SyncedFolder.Enable(m, &f, &o)
+	r.Error = p.SyncedFolder.Enable(m, f, o)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export SyncedFolderIsUsable
 func SyncedFolderIsUsable(pluginName, machine *C.char) *C.char {
-	r := vagrant.Response{}
+	r := &Response{}
 	p, err := getSyncedFolderPlugin(pluginName)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	m, err := vagrant.LoadMachine(C.GoString(machine), nil)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	r.Result, r.Error = p.SyncedFolder.IsUsable(m)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 //export SyncedFolderPrepare
 func SyncedFolderPrepare(pluginName, machine, folders, opts *C.char) *C.char {
-	r := vagrant.Response{}
+	r := &Response{}
 	p, err := getSyncedFolderPlugin(pluginName)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	m, err := vagrant.LoadMachine(C.GoString(machine), nil)
 	if err != nil {
 		r.Error = err
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	var f vagrant.FolderList
 	r.Error = json.Unmarshal([]byte(C.GoString(folders)), &f)
 	if r.Error != nil {
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
 	var o vagrant.FolderOptions
 	r.Error = json.Unmarshal([]byte(C.GoString(opts)), &o)
 	if r.Error != nil {
-		return C.CString(r.Dump())
+		return r.Dump()
 	}
-	r.Error = p.SyncedFolder.Prepare(m, &f, &o)
+	r.Error = p.SyncedFolder.Prepare(m, f, o)
-	return C.CString(r.Dump())
+	return r.Dump()
 }
 
 func getSyncedFolderPlugin(pluginName *C.char) (c *plugin.RemoteSyncedFolder, err error) {

ext/go-plugin/vagrant/capabilities.go

@@ -7,7 +7,7 @@ type SystemCapability struct {
 
 type ProviderCapability struct {
 	Name     string `json:"name"`
-	Provider string `json:"name"`
+	Provider string `json:"provider"`
 }
 
 type GuestCapabilities interface {

ext/go-plugin/vagrant/config.go

@@ -6,3 +6,10 @@ type Config interface {
 	ConfigValidate(data map[string]interface{}, m *Machine) (errors []string, err error)
 	ConfigFinalize(data map[string]interface{}) (finaldata map[string]interface{}, err error)
 }
+
+type NoConfig struct{}
+
+func (c *NoConfig) ConfigAttributes() (a []string, e error)                                   { return }
+func (c *NoConfig) ConfigLoad(map[string]interface{}) (d map[string]interface{}, e error)     { return }
+func (c *NoConfig) ConfigValidate(map[string]interface{}, *Machine) (es []string, e error)    { return }
+func (c *NoConfig) ConfigFinalize(map[string]interface{}) (f map[string]interface{}, e error) { return }

ext/go-plugin/vagrant/plugin/base.go

@@ -2,6 +2,7 @@ package plugin
 
 import (
 	"errors"
+	"fmt"
 	"os"
 	"os/exec"
 
@@ -11,6 +12,13 @@ import (
 	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant"
 )
 
+var (
+	Handshake = go_plugin.HandshakeConfig{
+		MagicCookieKey:   "VAGRANT_PLUGIN_MAGIC_COOKIE",
+		MagicCookieValue: "1561a662a76642f98df77ad025aa13a9b16225d93f90475e91090fbe577317ed",
+		ProtocolVersion:  1}
+)
+
 type RemoteConfig struct {
 	Client *go_plugin.Client
 	Config vagrant.Config
@@ -45,9 +53,36 @@ type VagrantPlugin struct {
 	Providers         map[string]*RemoteProvider
 	SyncedFolders     map[string]*RemoteSyncedFolder
 	PluginDirectories []string
+	PluginLookup      func(name, kind string) (p interface{}, err error)
 	Logger            hclog.Logger
 }
 
+func VagrantPluginInit() *VagrantPlugin {
+	v := &VagrantPlugin{
+		PluginDirectories: []string{},
+		Providers:         map[string]*RemoteProvider{},
+		SyncedFolders:     map[string]*RemoteSyncedFolder{},
+		Logger:            vagrant.DefaultLogger().Named("go-plugin")}
+	v.PluginLookup = v.DefaultPluginLookup
+	return v
+}
+
+func (v *VagrantPlugin) DefaultPluginLookup(name, kind string) (p interface{}, err error) {
+	switch kind {
+	case "provider":
+		p = v.Providers[name]
+	case "synced_folder":
+		p = v.SyncedFolders[name]
+	default:
+		err = errors.New("invalid plugin type")
+		return
+	}
+	if p == nil {
+		err = errors.New(fmt.Sprintf("Failed to locate %s plugin of type %s", name, kind))
+	}
+	return
+}
+
 func (v *VagrantPlugin) LoadPlugins(pluginPath string) error {
 	for _, p := range v.PluginDirectories {
 		if p == pluginPath {
@@ -78,11 +113,7 @@ func (v *VagrantPlugin) LoadProviders(pluginPath string) error {
 		client := go_plugin.NewClient(&go_plugin.ClientConfig{
 			AllowedProtocols: []go_plugin.Protocol{go_plugin.ProtocolGRPC},
 			Logger:           v.Logger,
-			HandshakeConfig: go_plugin.HandshakeConfig{
+			HandshakeConfig:  Handshake,
-				MagicCookieKey:   "BASIC_PLUGIN",
-				MagicCookieValue: "hello",
-				ProtocolVersion:  1,
-			},
 			Cmd:              exec.Command(providerPath),
 			VersionedPlugins: map[int]go_plugin.PluginSet{
 				2: {"provider": &ProviderPlugin{}}}})
@@ -121,11 +152,7 @@ func (v *VagrantPlugin) LoadSyncedFolders(pluginPath string) error {
 		client := go_plugin.NewClient(&go_plugin.ClientConfig{
 			AllowedProtocols: []go_plugin.Protocol{go_plugin.ProtocolGRPC},
 			Logger:           v.Logger,
-			HandshakeConfig: go_plugin.HandshakeConfig{
+			HandshakeConfig:  Handshake,
-				MagicCookieKey:   "BASIC_PLUGIN",
-				MagicCookieValue: "hello",
-				ProtocolVersion:  1,
-			},
 			Cmd:              exec.Command(folderPath),
 			VersionedPlugins: map[int]go_plugin.PluginSet{
 				2: {"synced_folders": &SyncedFolderPlugin{}}}})

ext/go-plugin/vagrant/plugin/capabilities.go

@@ -5,6 +5,8 @@ import (
 	"encoding/json"
 	"errors"
 
+	"google.golang.org/grpc"
+
 	go_plugin "github.com/hashicorp/go-plugin"
 	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant"
 	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin/proto/vagrant_caps"
@@ -21,6 +23,23 @@ type GuestCapabilitiesPlugin struct {
 	Impl GuestCapabilities
 }
 
+func (g *GuestCapabilitiesPlugin) GRPCServer(broker *go_plugin.GRPCBroker, s *grpc.Server) error {
+	g.Impl.Init()
+	vagrant_caps.RegisterGuestCapabilitiesServer(s, &GRPCGuestCapabilitiesServer{
+		Impl: g.Impl,
+		GRPCIOServer: GRPCIOServer{
+			Impl: g.Impl}})
+	return nil
+}
+
+func (g *GuestCapabilitiesPlugin) GRPCClient(ctx context.Context, broker *go_plugin.GRPCBroker, c *grpc.ClientConn) (interface{}, error) {
+	client := vagrant_caps.NewGuestCapabilitiesClient(c)
+	return &GRPCGuestCapabilitiesClient{
+		client: client,
+		GRPCIOClient: GRPCIOClient{
+			client: client}}, nil
+}
+
 type GRPCGuestCapabilitiesServer struct {
 	GRPCIOServer
 	Impl GuestCapabilities
@@ -43,8 +62,7 @@ func (s *GRPCGuestCapabilitiesServer) GuestCapabilities(ctx context.Context, req
 func (s *GRPCGuestCapabilitiesServer) GuestCapability(ctx context.Context, req *vagrant_caps.GuestCapabilityRequest) (resp *vagrant_caps.GuestCapabilityResponse, err error) {
 	resp = &vagrant_caps.GuestCapabilityResponse{}
 	var args interface{}
-	err = json.Unmarshal([]byte(req.Arguments), args)
+	if err = json.Unmarshal([]byte(req.Arguments), &args); err != nil {
-	if err != nil {
 		return
 	}
 	machine, err := vagrant.LoadMachine(req.Machine, s.Impl)
@@ -67,6 +85,8 @@ func (s *GRPCGuestCapabilitiesServer) GuestCapability(ctx context.Context, req *
 }
 
 type GRPCGuestCapabilitiesClient struct {
+	GRPCCoreClient
+	GRPCIOClient
 	client vagrant_caps.GuestCapabilitiesClient
 }
 
@@ -102,6 +122,13 @@ func (c *GRPCGuestCapabilitiesClient) GuestCapability(cap *vagrant.SystemCapabil
 		Capability: &vagrant_caps.Capability{Name: cap.Name, Platform: cap.Platform},
 		Machine:    m,
 		Arguments:  string(a)})
+	if err != nil {
+		return
+	}
+	if resp.Error != "" {
+		err = errors.New(resp.Error)
+		return
+	}
 	err = json.Unmarshal([]byte(resp.Result), &result)
 	return
 }
@@ -111,6 +138,28 @@ type HostCapabilities interface {
 	Meta
 }
 
+type HostCapabilitiesPlugin struct {
+	go_plugin.NetRPCUnsupportedPlugin
+	Impl HostCapabilities
+}
+
+func (h *HostCapabilitiesPlugin) GRPCServer(broker *go_plugin.GRPCBroker, s *grpc.Server) error {
+	h.Impl.Init()
+	vagrant_caps.RegisterHostCapabilitiesServer(s, &GRPCHostCapabilitiesServer{
+		Impl: h.Impl,
+		GRPCIOServer: GRPCIOServer{
+			Impl: h.Impl}})
+	return nil
+}
+
+func (h *HostCapabilitiesPlugin) GRPCClient(ctx context.Context, broker *go_plugin.GRPCBroker, c *grpc.ClientConn) (interface{}, error) {
+	client := vagrant_caps.NewHostCapabilitiesClient(c)
+	return &GRPCHostCapabilitiesClient{
+		client: client,
+		GRPCIOClient: GRPCIOClient{
+			client: client}}, nil
+}
+
 type GRPCHostCapabilitiesServer struct {
 	GRPCIOServer
 	Impl HostCapabilities
@@ -133,8 +182,7 @@ func (s *GRPCHostCapabilitiesServer) HostCapabilities(ctx context.Context, req *
 func (s *GRPCHostCapabilitiesServer) HostCapability(ctx context.Context, req *vagrant_caps.HostCapabilityRequest) (resp *vagrant_caps.HostCapabilityResponse, err error) {
 	resp = &vagrant_caps.HostCapabilityResponse{}
 	var args interface{}
-	err = json.Unmarshal([]byte(req.Arguments), args)
+	if err = json.Unmarshal([]byte(req.Arguments), &args); err != nil {
-	if err != nil {
 		return
 	}
 	env, err := vagrant.LoadEnvironment(req.Environment, s.Impl)
@@ -157,6 +205,8 @@ func (s *GRPCHostCapabilitiesServer) HostCapability(ctx context.Context, req *va
 }
 
 type GRPCHostCapabilitiesClient struct {
+	GRPCCoreClient
+	GRPCIOClient
 	client vagrant_caps.HostCapabilitiesClient
 }
 
@@ -194,6 +244,9 @@ func (c *GRPCHostCapabilitiesClient) HostCapability(cap *vagrant.SystemCapabilit
 			Platform: cap.Platform},
 		Environment: e,
 		Arguments:   string(a)})
+	if err != nil {
+		return
+	}
 	err = json.Unmarshal([]byte(resp.Result), &result)
 	return
 }
@@ -203,6 +256,28 @@ type ProviderCapabilities interface {
 	Meta
 }
 
+type ProviderCapabilitiesPlugin struct {
+	go_plugin.NetRPCUnsupportedPlugin
+	Impl ProviderCapabilities
+}
+
+func (p *ProviderCapabilitiesPlugin) GRPCServer(broker *go_plugin.GRPCBroker, s *grpc.Server) error {
+	p.Impl.Init()
+	vagrant_caps.RegisterProviderCapabilitiesServer(s, &GRPCProviderCapabilitiesServer{
+		Impl: p.Impl,
+		GRPCIOServer: GRPCIOServer{
+			Impl: p.Impl}})
+	return nil
+}
+
+func (p *ProviderCapabilitiesPlugin) GRPCClient(ctx context.Context, broker *go_plugin.GRPCBroker, c *grpc.ClientConn) (interface{}, error) {
+	client := vagrant_caps.NewProviderCapabilitiesClient(c)
+	return &GRPCProviderCapabilitiesClient{
+		client: client,
+		GRPCIOClient: GRPCIOClient{
+			client: client}}, nil
+}
+
 type GRPCProviderCapabilitiesServer struct {
 	GRPCIOServer
 	Impl ProviderCapabilities
@@ -225,7 +300,7 @@ func (s *GRPCProviderCapabilitiesServer) ProviderCapabilities(ctx context.Contex
 func (s *GRPCProviderCapabilitiesServer) ProviderCapability(ctx context.Context, req *vagrant_caps.ProviderCapabilityRequest) (resp *vagrant_caps.ProviderCapabilityResponse, err error) {
 	resp = &vagrant_caps.ProviderCapabilityResponse{}
 	var args interface{}
-	err = json.Unmarshal([]byte(req.Arguments), args)
+	err = json.Unmarshal([]byte(req.Arguments), &args)
 	if err != nil {
 		return
 	}
@@ -249,6 +324,8 @@ func (s *GRPCProviderCapabilitiesServer) ProviderCapability(ctx context.Context,
 }
 
 type GRPCProviderCapabilitiesClient struct {
+	GRPCCoreClient
+	GRPCIOClient
 	client vagrant_caps.ProviderCapabilitiesClient
 }
 
@@ -286,6 +363,9 @@ func (c *GRPCProviderCapabilitiesClient) ProviderCapability(cap *vagrant.Provide
 			Provider: cap.Provider},
 		Machine:   m,
 		Arguments: string(a)})
+	if err != nil {
+		return
+	}
 	err = json.Unmarshal([]byte(resp.Result), &result)
 	return
 }

ext/go-plugin/vagrant/plugin/capabilities_test.go

@@ -0,0 +1,311 @@
+package plugin
+
+import (
+	"testing"
+
+	"github.com/hashicorp/go-plugin"
+	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant"
+)
+
+func TestCapabilities_GuestCapabilities(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &GuestCapabilitiesPlugin{Impl: &MockGuestCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(GuestCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+	resp, err := impl.GuestCapabilities()
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	if len(resp) != 1 {
+		t.Fatalf("length %d != 1", len(resp))
+	}
+	if resp[0].Name != "test_cap" {
+		t.Errorf("name - %s != test_cap", resp[0].Name)
+	}
+	if resp[0].Platform != "testOS" {
+		t.Errorf("platform - %s != testOS", resp[0].Platform)
+	}
+}
+
+func TestCapabilities_GuestCapability(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &GuestCapabilitiesPlugin{Impl: &MockGuestCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(GuestCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	cap := &vagrant.SystemCapability{
+		Name:     "test_cap",
+		Platform: "TestOS"}
+	m := &vagrant.Machine{}
+	args := []string{"test_value", "next_test_value"}
+
+	resp, err := impl.GuestCapability(cap, args, m)
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	result, ok := resp.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", result)
+	}
+	if result[0] != "test_cap" {
+		t.Errorf("%s != test_cap", result[0])
+	}
+	if result[1] != "test_value" {
+		t.Errorf("%s != test_value", result[1])
+	}
+}
+
+func TestCapabilities_GuestCapability_noargs(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &GuestCapabilitiesPlugin{Impl: &MockGuestCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(GuestCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	cap := &vagrant.SystemCapability{
+		Name:     "test_cap",
+		Platform: "TestOS"}
+	m := &vagrant.Machine{}
+	var args interface{}
+	args = nil
+
+	resp, err := impl.GuestCapability(cap, args, m)
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	result, ok := resp.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", result)
+	}
+	if result[0] != "test_cap" {
+		t.Errorf("%s != test_cap", result[0])
+	}
+}
+
+func TestCapabilities_HostCapabilities(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &HostCapabilitiesPlugin{Impl: &MockHostCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(HostCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+	resp, err := impl.HostCapabilities()
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	if len(resp) != 1 {
+		t.Fatalf("length %d != 1", len(resp))
+	}
+	if resp[0].Name != "test_cap" {
+		t.Errorf("name - %s != test_cap", resp[0].Name)
+	}
+	if resp[0].Platform != "testOS" {
+		t.Errorf("platform - %s != testOS", resp[0].Platform)
+	}
+}
+
+func TestCapabilities_HostCapability(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &HostCapabilitiesPlugin{Impl: &MockHostCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(HostCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	cap := &vagrant.SystemCapability{
+		Name:     "test_cap",
+		Platform: "TestOS"}
+	e := &vagrant.Environment{}
+	args := []string{"test_value", "next_test_value"}
+
+	resp, err := impl.HostCapability(cap, args, e)
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	result, ok := resp.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", result)
+	}
+	if result[0] != "test_cap" {
+		t.Errorf("%s != test_cap", result[0])
+	}
+	if result[1] != "test_value" {
+		t.Errorf("%s != test_value", result[1])
+	}
+}
+
+func TestCapabilities_HostCapability_noargs(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &HostCapabilitiesPlugin{Impl: &MockHostCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(HostCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	cap := &vagrant.SystemCapability{
+		Name:     "test_cap",
+		Platform: "TestOS"}
+	e := &vagrant.Environment{}
+	var args interface{}
+	args = nil
+
+	resp, err := impl.HostCapability(cap, args, e)
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	result, ok := resp.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", result)
+	}
+	if result[0] != "test_cap" {
+		t.Errorf("%s != test_cap", result[0])
+	}
+}
+
+func TestCapabilities_ProviderCapabilities(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &ProviderCapabilitiesPlugin{Impl: &MockProviderCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(ProviderCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+	resp, err := impl.ProviderCapabilities()
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	if len(resp) != 1 {
+		t.Fatalf("length %d != 1", len(resp))
+	}
+	if resp[0].Name != "test_cap" {
+		t.Errorf("name - %s != test_cap", resp[0].Name)
+	}
+	if resp[0].Provider != "testProvider" {
+		t.Errorf("provider - %s != testProvdier", resp[0].Provider)
+	}
+}
+
+func TestCapabilities_ProviderCapability(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &ProviderCapabilitiesPlugin{Impl: &MockProviderCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(ProviderCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	cap := &vagrant.ProviderCapability{
+		Name:     "test_cap",
+		Provider: "test_provider"}
+	m := &vagrant.Machine{}
+	args := []string{"test_value", "next_test_value"}
+
+	resp, err := impl.ProviderCapability(cap, args, m)
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	result, ok := resp.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", result)
+	}
+	if result[0] != "test_cap" {
+		t.Errorf("%s != test_cap", result[0])
+	}
+	if result[1] != "test_value" {
+		t.Errorf("%s != test_value", result[1])
+	}
+}
+
+func TestCapabilities_ProviderCapability_noargs(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"caps": &ProviderCapabilitiesPlugin{Impl: &MockProviderCapabilities{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("caps")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(ProviderCapabilities)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	cap := &vagrant.ProviderCapability{
+		Name:     "test_cap",
+		Provider: "test_provider"}
+	m := &vagrant.Machine{}
+	var args interface{}
+	args = nil
+
+	resp, err := impl.ProviderCapability(cap, args, m)
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	result, ok := resp.([]interface{})
+	if !ok {
+		t.Fatalf("bad %#v", result)
+	}
+	if result[0] != "test_cap" {
+		t.Errorf("%s != test_cap", result[0])
+	}
+}

ext/go-plugin/vagrant/plugin/config.go

@@ -5,6 +5,8 @@ import (
 	"encoding/json"
 	"errors"
 
+	"google.golang.org/grpc"
+
 	go_plugin "github.com/hashicorp/go-plugin"
 	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant"
 	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin/proto/vagrant_common"
@@ -21,6 +23,23 @@ type ConfigPlugin struct {
 	Impl Config
 }
 
+func (c *ConfigPlugin) GRPCServer(broker *go_plugin.GRPCBroker, s *grpc.Server) error {
+	c.Impl.Init()
+	vagrant_config.RegisterConfigServer(s, &GRPCConfigServer{
+		Impl: c.Impl,
+		GRPCIOServer: GRPCIOServer{
+			Impl: c.Impl}})
+	return nil
+}
+
+func (c *ConfigPlugin) GRPCClient(ctx context.Context, broker *go_plugin.GRPCBroker, con *grpc.ClientConn) (interface{}, error) {
+	client := vagrant_config.NewConfigClient(con)
+	return &GRPCConfigClient{
+		client: client,
+		GRPCIOClient: GRPCIOClient{
+			client: client}}, nil
+}
+
 type GRPCConfigServer struct {
 	GRPCIOServer
 	Impl Config
@@ -104,6 +123,8 @@ func (s *GRPCConfigServer) ConfigFinalize(ctx context.Context, req *vagrant_conf
 }
 
 type GRPCConfigClient struct {
+	GRPCCoreClient
+	GRPCIOClient
 	client vagrant_config.ConfigClient
 }
 

ext/go-plugin/vagrant/plugin/config_test.go

@@ -0,0 +1,131 @@
+package plugin
+
+import (
+	"testing"
+
+	"github.com/hashicorp/go-plugin"
+	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant"
+)
+
+func TestConfigPlugin_Attributes(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"configs": &ConfigPlugin{Impl: &MockConfig{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("configs")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Config)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	resp, err := impl.ConfigAttributes()
+	if err != nil {
+		t.Fatalf("bad resp %s", err)
+	}
+	if resp[0] != "fubar" {
+		t.Errorf("%s != fubar", resp[0])
+	}
+	if resp[1] != "foobar" {
+		t.Errorf("%s != foobar", resp[1])
+	}
+}
+
+func TestConfigPlugin_Load(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"configs": &ConfigPlugin{Impl: &MockConfig{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("configs")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Config)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	data := map[string]interface{}{}
+
+	resp, err := impl.ConfigLoad(data)
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	if _, ok := resp["test_key"]; !ok {
+		t.Fatalf("bad resp content %#v", resp)
+	}
+	v := resp["test_key"].(string)
+	if v != "test_val" {
+		t.Errorf("%s != test_val", v)
+	}
+}
+
+func TestConfigPlugin_Validate(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"configs": &ConfigPlugin{Impl: &MockConfig{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("configs")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Config)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	data := map[string]interface{}{}
+	machine := &vagrant.Machine{}
+
+	resp, err := impl.ConfigValidate(data, machine)
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	if len(resp) != 1 {
+		t.Fatalf("bad size %d != 1", len(resp))
+	}
+	if resp[0] != "test error" {
+		t.Errorf("%s != test error", resp[0])
+	}
+}
+
+func TestConfigPlugin_Finalize(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"configs": &ConfigPlugin{Impl: &MockConfig{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("configs")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Config)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	data := map[string]interface{}{
+		"test_key":  "test_val",
+		"other_key": "other_val"}
+
+	resp, err := impl.ConfigFinalize(data)
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	if _, ok := resp["test_key"]; !ok {
+		t.Fatalf("bad resp content %#v", resp)
+	}
+	v := resp["test_key"].(string)
+	if v != "test_val-updated" {
+		t.Errorf("%s != test_val-updated", v)
+	}
+	v = resp["other_key"].(string)
+	if v != "other_val-updated" {
+		t.Errorf("%s != other_val-updated", v)
+	}
+}

ext/go-plugin/vagrant/plugin/io.go

@@ -11,6 +11,10 @@ import (
 	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin/proto/vagrant_io"
 )
 
+type IO interface {
+	vagrant.StreamIO
+}
+
 type IOPlugin struct {
 	go_plugin.NetRPCUnsupportedPlugin
 	Impl vagrant.StreamIO

ext/go-plugin/vagrant/plugin/io_test.go

@@ -0,0 +1,89 @@
+package plugin
+
+import (
+	"testing"
+
+	"github.com/hashicorp/go-plugin"
+)
+
+type MockIO struct {
+	Core
+}
+
+func TestIO_ReadWrite(t *testing.T) {
+	ioplugin := &MockIO{}
+	ioplugin.Init()
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"io": &IOPlugin{Impl: ioplugin}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("io")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(IO)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+	go func() {
+		length, err := impl.Write("test_message", "stdout")
+		if err != nil {
+			t.Fatalf("bad write: %s", err)
+		}
+		if length != len("test_message") {
+			t.Fatalf("bad length %d != %d", length, len("test_message"))
+		}
+	}()
+	resp, err := impl.Read("stdout")
+	if err != nil {
+		t.Fatalf("bad read: %s", err)
+	}
+	if resp != "test_message" {
+		t.Errorf("%s != test_message", resp)
+	}
+}
+
+func TestIO_Write_bad(t *testing.T) {
+	ioplugin := &MockIO{}
+	ioplugin.Init()
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"io": &IOPlugin{Impl: ioplugin}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("io")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(IO)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+	_, err = impl.Write("test_message", "bad-target")
+	if err == nil {
+		t.Fatalf("illegal write")
+	}
+}
+
+func TestIO_Read_bad(t *testing.T) {
+	ioplugin := &MockIO{}
+	ioplugin.Init()
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"io": &IOPlugin{Impl: ioplugin}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("io")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(IO)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+	_, err = impl.Read("bad-target")
+	if err == nil {
+		t.Fatalf("illegal read")
+	}
+}

ext/go-plugin/vagrant/plugin/mocks.go

@@ -0,0 +1,176 @@
+package plugin
+
+import (
+	"errors"
+
+	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant"
+)
+
+type MockGuestCapabilities struct{ Core }
+
+func (g *MockGuestCapabilities) GuestCapabilities() (caps []vagrant.SystemCapability, err error) {
+	caps = []vagrant.SystemCapability{
+		vagrant.SystemCapability{Name: "test_cap", Platform: "testOS"}}
+	return
+}
+
+func (g *MockGuestCapabilities) GuestCapability(cap *vagrant.SystemCapability, args interface{}, m *vagrant.Machine) (result interface{}, err error) {
+	if args != nil {
+		arguments := args.([]interface{})
+		if len(arguments) > 0 {
+			result = []string{
+				cap.Name,
+				arguments[0].(string)}
+			return
+		}
+	}
+	result = []string{cap.Name}
+	return
+}
+
+type MockHostCapabilities struct{ Core }
+
+func (h *MockHostCapabilities) HostCapabilities() (caps []vagrant.SystemCapability, err error) {
+	caps = []vagrant.SystemCapability{
+		vagrant.SystemCapability{Name: "test_cap", Platform: "testOS"}}
+	return
+}
+
+func (h *MockHostCapabilities) HostCapability(cap *vagrant.SystemCapability, args interface{}, e *vagrant.Environment) (result interface{}, err error) {
+	if args != nil {
+		arguments := args.([]interface{})
+		if len(arguments) > 0 {
+			result = []string{
+				cap.Name,
+				arguments[0].(string)}
+			return
+		}
+	}
+	result = []string{cap.Name}
+	return
+}
+
+type MockProviderCapabilities struct{ Core }
+
+func (p *MockProviderCapabilities) ProviderCapabilities() (caps []vagrant.ProviderCapability, err error) {
+	caps = []vagrant.ProviderCapability{
+		vagrant.ProviderCapability{Name: "test_cap", Provider: "testProvider"}}
+	return
+}
+
+func (p *MockProviderCapabilities) ProviderCapability(cap *vagrant.ProviderCapability, args interface{}, m *vagrant.Machine) (result interface{}, err error) {
+	if args != nil {
+		arguments := args.([]interface{})
+		if len(arguments) > 0 {
+			result = []string{
+				cap.Name,
+				arguments[0].(string)}
+			return
+		}
+	}
+	result = []string{cap.Name}
+	return
+}
+
+type MockConfig struct {
+	Core
+}
+
+func (c *MockConfig) ConfigAttributes() (attrs []string, err error) {
+	attrs = []string{"fubar", "foobar"}
+	return
+}
+
+func (c *MockConfig) ConfigLoad(data map[string]interface{}) (loaddata map[string]interface{}, err error) {
+	loaddata = map[string]interface{}{
+		"test_key": "test_val"}
+	if data["test_key"] != nil {
+		loaddata["sent_key"] = data["test_key"]
+	}
+	return
+}
+
+func (c *MockConfig) ConfigValidate(data map[string]interface{}, m *vagrant.Machine) (errors []string, err error) {
+	errors = []string{"test error"}
+	return
+}
+
+func (c *MockConfig) ConfigFinalize(data map[string]interface{}) (finaldata map[string]interface{}, err error) {
+	finaldata = make(map[string]interface{})
+	for key, tval := range data {
+		val := tval.(string)
+		finaldata[key] = val + "-updated"
+	}
+	return
+}
+
+type MockProvider struct {
+	Core
+	vagrant.NoConfig
+	vagrant.NoGuestCapabilities
+	vagrant.NoHostCapabilities
+	vagrant.NoProviderCapabilities
+}
+
+func (c *MockProvider) Action(actionName string, m *vagrant.Machine) (actions []string, err error) {
+	if actionName == "valid" {
+		actions = []string{"self::DoTask"}
+	} else {
+		err = errors.New("Unknown action requested")
+	}
+	return
+}
+
+func (c *MockProvider) IsInstalled(m *vagrant.Machine) (bool, error) {
+	return true, nil
+}
+
+func (c *MockProvider) IsUsable(m *vagrant.Machine) (bool, error) {
+	return true, nil
+}
+
+func (c *MockProvider) MachineIdChanged(m *vagrant.Machine) error {
+	return nil
+}
+
+func (c *MockProvider) Name() string {
+	return "mock_provider"
+}
+
+func (c *MockProvider) RunAction(actionName string, args interface{}, m *vagrant.Machine) (r interface{}, err error) {
+	if actionName != "valid" && actionName != "send_output" {
+		err = errors.New("invalid action name")
+		return
+	}
+	if actionName == "send_output" {
+		m.UI.Say("test_output_p")
+	}
+	var arguments []interface{}
+	if args != nil {
+		arguments = args.([]interface{})
+	} else {
+		arguments = []interface{}{"unset"}
+	}
+	r = []string{
+		actionName,
+		arguments[0].(string)}
+	return
+}
+
+func (c *MockProvider) SshInfo(m *vagrant.Machine) (*vagrant.SshInfo, error) {
+	return &vagrant.SshInfo{
+		Host: "localhost",
+		Port: 2222}, nil
+}
+
+func (c *MockProvider) State(m *vagrant.Machine) (*vagrant.MachineState, error) {
+	return &vagrant.MachineState{
+		Id:        "default",
+		ShortDesc: "running"}, nil
+}
+
+func (c *MockProvider) Info() *vagrant.ProviderInfo {
+	return &vagrant.ProviderInfo{
+		Description: "Custom",
+		Priority:    10}
+}

ext/go-plugin/vagrant/plugin/proto/vagrant_caps/capabilities.pb.go

@@ -7,6 +7,7 @@ import proto "github.com/golang/protobuf/proto"
 import fmt "fmt"
 import math "math"
 import vagrant_common "github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin/proto/vagrant_common"
+import vagrant_io "github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin/proto/vagrant_io"
 
 import (
 	context "golang.org/x/net/context"
@@ -535,6 +536,9 @@ const _ = grpc.SupportPackageIsVersion4
 type GuestCapabilitiesClient interface {
 	GuestCapabilities(ctx context.Context, in *vagrant_common.NullRequest, opts ...grpc.CallOption) (*CapabilitiesResponse, error)
 	GuestCapability(ctx context.Context, in *GuestCapabilityRequest, opts ...grpc.CallOption) (*GuestCapabilityResponse, error)
+	// These are IO helpers for streaming
+	Read(ctx context.Context, in *vagrant_io.ReadRequest, opts ...grpc.CallOption) (*vagrant_io.ReadResponse, error)
+	Write(ctx context.Context, in *vagrant_io.WriteRequest, opts ...grpc.CallOption) (*vagrant_io.WriteResponse, error)
 }
 
 type guestCapabilitiesClient struct {
@@ -563,10 +567,31 @@ func (c *guestCapabilitiesClient) GuestCapability(ctx context.Context, in *Guest
 	return out, nil
 }
 
+func (c *guestCapabilitiesClient) Read(ctx context.Context, in *vagrant_io.ReadRequest, opts ...grpc.CallOption) (*vagrant_io.ReadResponse, error) {
+	out := new(vagrant_io.ReadResponse)
+	err := c.cc.Invoke(ctx, "/vagrant.caps.GuestCapabilities/Read", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *guestCapabilitiesClient) Write(ctx context.Context, in *vagrant_io.WriteRequest, opts ...grpc.CallOption) (*vagrant_io.WriteResponse, error) {
+	out := new(vagrant_io.WriteResponse)
+	err := c.cc.Invoke(ctx, "/vagrant.caps.GuestCapabilities/Write", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 // GuestCapabilitiesServer is the server API for GuestCapabilities service.
 type GuestCapabilitiesServer interface {
 	GuestCapabilities(context.Context, *vagrant_common.NullRequest) (*CapabilitiesResponse, error)
 	GuestCapability(context.Context, *GuestCapabilityRequest) (*GuestCapabilityResponse, error)
+	// These are IO helpers for streaming
+	Read(context.Context, *vagrant_io.ReadRequest) (*vagrant_io.ReadResponse, error)
+	Write(context.Context, *vagrant_io.WriteRequest) (*vagrant_io.WriteResponse, error)
 }
 
 func RegisterGuestCapabilitiesServer(s *grpc.Server, srv GuestCapabilitiesServer) {
@@ -609,6 +634,42 @@ func _GuestCapabilities_GuestCapability_Handler(srv interface{}, ctx context.Con
 	return interceptor(ctx, in, info, handler)
 }
 
+func _GuestCapabilities_Read_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(vagrant_io.ReadRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(GuestCapabilitiesServer).Read(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/vagrant.caps.GuestCapabilities/Read",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(GuestCapabilitiesServer).Read(ctx, req.(*vagrant_io.ReadRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _GuestCapabilities_Write_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(vagrant_io.WriteRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(GuestCapabilitiesServer).Write(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/vagrant.caps.GuestCapabilities/Write",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(GuestCapabilitiesServer).Write(ctx, req.(*vagrant_io.WriteRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
 var _GuestCapabilities_serviceDesc = grpc.ServiceDesc{
 	ServiceName: "vagrant.caps.GuestCapabilities",
 	HandlerType: (*GuestCapabilitiesServer)(nil),
@@ -621,6 +682,14 @@ var _GuestCapabilities_serviceDesc = grpc.ServiceDesc{
 			MethodName: "GuestCapability",
 			Handler:    _GuestCapabilities_GuestCapability_Handler,
 		},
+		{
+			MethodName: "Read",
+			Handler:    _GuestCapabilities_Read_Handler,
+		},
+		{
+			MethodName: "Write",
+			Handler:    _GuestCapabilities_Write_Handler,
+		},
 	},
 	Streams:  []grpc.StreamDesc{},
 	Metadata: "vagrant_caps/capabilities.proto",
@@ -632,6 +701,9 @@ var _GuestCapabilities_serviceDesc = grpc.ServiceDesc{
 type HostCapabilitiesClient interface {
 	HostCapabilities(ctx context.Context, in *vagrant_common.NullRequest, opts ...grpc.CallOption) (*CapabilitiesResponse, error)
 	HostCapability(ctx context.Context, in *HostCapabilityRequest, opts ...grpc.CallOption) (*HostCapabilityResponse, error)
+	// These are IO helpers for streaming
+	Read(ctx context.Context, in *vagrant_io.ReadRequest, opts ...grpc.CallOption) (*vagrant_io.ReadResponse, error)
+	Write(ctx context.Context, in *vagrant_io.WriteRequest, opts ...grpc.CallOption) (*vagrant_io.WriteResponse, error)
 }
 
 type hostCapabilitiesClient struct {
@@ -660,10 +732,31 @@ func (c *hostCapabilitiesClient) HostCapability(ctx context.Context, in *HostCap
 	return out, nil
 }
 
+func (c *hostCapabilitiesClient) Read(ctx context.Context, in *vagrant_io.ReadRequest, opts ...grpc.CallOption) (*vagrant_io.ReadResponse, error) {
+	out := new(vagrant_io.ReadResponse)
+	err := c.cc.Invoke(ctx, "/vagrant.caps.HostCapabilities/Read", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *hostCapabilitiesClient) Write(ctx context.Context, in *vagrant_io.WriteRequest, opts ...grpc.CallOption) (*vagrant_io.WriteResponse, error) {
+	out := new(vagrant_io.WriteResponse)
+	err := c.cc.Invoke(ctx, "/vagrant.caps.HostCapabilities/Write", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 // HostCapabilitiesServer is the server API for HostCapabilities service.
 type HostCapabilitiesServer interface {
 	HostCapabilities(context.Context, *vagrant_common.NullRequest) (*CapabilitiesResponse, error)
 	HostCapability(context.Context, *HostCapabilityRequest) (*HostCapabilityResponse, error)
+	// These are IO helpers for streaming
+	Read(context.Context, *vagrant_io.ReadRequest) (*vagrant_io.ReadResponse, error)
+	Write(context.Context, *vagrant_io.WriteRequest) (*vagrant_io.WriteResponse, error)
 }
 
 func RegisterHostCapabilitiesServer(s *grpc.Server, srv HostCapabilitiesServer) {
@@ -706,6 +799,42 @@ func _HostCapabilities_HostCapability_Handler(srv interface{}, ctx context.Conte
 	return interceptor(ctx, in, info, handler)
 }
 
+func _HostCapabilities_Read_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(vagrant_io.ReadRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(HostCapabilitiesServer).Read(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/vagrant.caps.HostCapabilities/Read",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(HostCapabilitiesServer).Read(ctx, req.(*vagrant_io.ReadRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _HostCapabilities_Write_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(vagrant_io.WriteRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(HostCapabilitiesServer).Write(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/vagrant.caps.HostCapabilities/Write",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(HostCapabilitiesServer).Write(ctx, req.(*vagrant_io.WriteRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
 var _HostCapabilities_serviceDesc = grpc.ServiceDesc{
 	ServiceName: "vagrant.caps.HostCapabilities",
 	HandlerType: (*HostCapabilitiesServer)(nil),
@@ -718,6 +847,14 @@ var _HostCapabilities_serviceDesc = grpc.ServiceDesc{
 			MethodName: "HostCapability",
 			Handler:    _HostCapabilities_HostCapability_Handler,
 		},
+		{
+			MethodName: "Read",
+			Handler:    _HostCapabilities_Read_Handler,
+		},
+		{
+			MethodName: "Write",
+			Handler:    _HostCapabilities_Write_Handler,
+		},
 	},
 	Streams:  []grpc.StreamDesc{},
 	Metadata: "vagrant_caps/capabilities.proto",
@@ -729,6 +866,9 @@ var _HostCapabilities_serviceDesc = grpc.ServiceDesc{
 type ProviderCapabilitiesClient interface {
 	ProviderCapabilities(ctx context.Context, in *vagrant_common.NullRequest, opts ...grpc.CallOption) (*ProviderCapabilitiesResponse, error)
 	ProviderCapability(ctx context.Context, in *ProviderCapabilityRequest, opts ...grpc.CallOption) (*ProviderCapabilityResponse, error)
+	// These are IO helpers for streaming
+	Read(ctx context.Context, in *vagrant_io.ReadRequest, opts ...grpc.CallOption) (*vagrant_io.ReadResponse, error)
+	Write(ctx context.Context, in *vagrant_io.WriteRequest, opts ...grpc.CallOption) (*vagrant_io.WriteResponse, error)
 }
 
 type providerCapabilitiesClient struct {
@@ -757,10 +897,31 @@ func (c *providerCapabilitiesClient) ProviderCapability(ctx context.Context, in
 	return out, nil
 }
 
+func (c *providerCapabilitiesClient) Read(ctx context.Context, in *vagrant_io.ReadRequest, opts ...grpc.CallOption) (*vagrant_io.ReadResponse, error) {
+	out := new(vagrant_io.ReadResponse)
+	err := c.cc.Invoke(ctx, "/vagrant.caps.ProviderCapabilities/Read", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *providerCapabilitiesClient) Write(ctx context.Context, in *vagrant_io.WriteRequest, opts ...grpc.CallOption) (*vagrant_io.WriteResponse, error) {
+	out := new(vagrant_io.WriteResponse)
+	err := c.cc.Invoke(ctx, "/vagrant.caps.ProviderCapabilities/Write", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 // ProviderCapabilitiesServer is the server API for ProviderCapabilities service.
 type ProviderCapabilitiesServer interface {
 	ProviderCapabilities(context.Context, *vagrant_common.NullRequest) (*ProviderCapabilitiesResponse, error)
 	ProviderCapability(context.Context, *ProviderCapabilityRequest) (*ProviderCapabilityResponse, error)
+	// These are IO helpers for streaming
+	Read(context.Context, *vagrant_io.ReadRequest) (*vagrant_io.ReadResponse, error)
+	Write(context.Context, *vagrant_io.WriteRequest) (*vagrant_io.WriteResponse, error)
 }
 
 func RegisterProviderCapabilitiesServer(s *grpc.Server, srv ProviderCapabilitiesServer) {
@@ -803,6 +964,42 @@ func _ProviderCapabilities_ProviderCapability_Handler(srv interface{}, ctx conte
 	return interceptor(ctx, in, info, handler)
 }
 
+func _ProviderCapabilities_Read_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(vagrant_io.ReadRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(ProviderCapabilitiesServer).Read(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/vagrant.caps.ProviderCapabilities/Read",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(ProviderCapabilitiesServer).Read(ctx, req.(*vagrant_io.ReadRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _ProviderCapabilities_Write_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(vagrant_io.WriteRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(ProviderCapabilitiesServer).Write(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/vagrant.caps.ProviderCapabilities/Write",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(ProviderCapabilitiesServer).Write(ctx, req.(*vagrant_io.WriteRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
 var _ProviderCapabilities_serviceDesc = grpc.ServiceDesc{
 	ServiceName: "vagrant.caps.ProviderCapabilities",
 	HandlerType: (*ProviderCapabilitiesServer)(nil),
@@ -815,6 +1012,14 @@ var _ProviderCapabilities_serviceDesc = grpc.ServiceDesc{
 			MethodName: "ProviderCapability",
 			Handler:    _ProviderCapabilities_ProviderCapability_Handler,
 		},
+		{
+			MethodName: "Read",
+			Handler:    _ProviderCapabilities_Read_Handler,
+		},
+		{
+			MethodName: "Write",
+			Handler:    _ProviderCapabilities_Write_Handler,
+		},
 	},
 	Streams:  []grpc.StreamDesc{},
 	Metadata: "vagrant_caps/capabilities.proto",
@@ -823,37 +1028,40 @@ var _ProviderCapabilities_serviceDesc = grpc.ServiceDesc{
 func init() { proto.RegisterFile("vagrant_caps/capabilities.proto", fileDescriptor_591a3013bd09a9cb) }
 
 var fileDescriptor_591a3013bd09a9cb = []byte{
-	// 510 bytes of a gzipped FileDescriptorProto
+	// 560 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xac, 0x95, 0xcf, 0x6e, 0xd3, 0x40,
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xc4, 0x95, 0x4d, 0x6f, 0xd3, 0x30,
-	0x10, 0xc6, 0xb5, 0x14, 0x0a, 0x9d, 0x56, 0xfc, 0x59, 0x85, 0x60, 0x4c, 0x25, 0x22, 0x53, 0x44,
+	0x18, 0xc7, 0x95, 0xee, 0x05, 0xf6, 0x6c, 0xe2, 0xc5, 0x2a, 0x5d, 0x16, 0x26, 0x51, 0x85, 0x21,
-	0x84, 0x84, 0x2d, 0x85, 0x0b, 0x87, 0x1e, 0x90, 0xa8, 0x28, 0xe2, 0x80, 0x50, 0xe0, 0x56, 0x89,
+	0x2a, 0x24, 0x12, 0xa9, 0x5c, 0x40, 0xda, 0x01, 0x89, 0x89, 0x21, 0x0e, 0x08, 0x75, 0x48, 0x1c,
-	0x6a, 0x63, 0x16, 0x7b, 0x91, 0xbd, 0x6b, 0x76, 0xd7, 0x11, 0xe5, 0x11, 0xb8, 0x71, 0xe0, 0x8d,
+	0x26, 0x31, 0xb9, 0x9d, 0x49, 0x8d, 0x12, 0x3b, 0xd8, 0x4e, 0xc5, 0xf8, 0x08, 0xdc, 0x38, 0xf0,
-	0xb8, 0xf0, 0x16, 0x3c, 0x0a, 0xb2, 0xbd, 0x71, 0xed, 0x7a, 0x5d, 0x97, 0xd2, 0x53, 0x32, 0x93,
+	0x71, 0xb8, 0xf0, 0x2d, 0xf8, 0x36, 0x28, 0x89, 0x93, 0x25, 0x8b, 0xbb, 0x8c, 0xad, 0xd2, 0x4e,
-	0x99, 0xf9, 0xe6, 0xfb, 0xd9, 0x9a, 0xc0, 0xfd, 0x25, 0x89, 0x24, 0xe1, 0xfa, 0x30, 0x24, 0x99,
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 }

ext/go-plugin/vagrant/plugin/proto/vagrant_caps/capabilities.proto

@@ -2,6 +2,7 @@ syntax = "proto3";
 package vagrant.caps;
 
 import "github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin/proto/vagrant_common/common.proto";
+import "github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin/proto/vagrant_io/io.proto";
 
 message Capability {
   string name = 1;
@@ -59,14 +60,23 @@ message HostCapabilityResponse {
 service GuestCapabilities {
   rpc GuestCapabilities(vagrant.common.NullRequest) returns (CapabilitiesResponse);
   rpc GuestCapability(GuestCapabilityRequest) returns (GuestCapabilityResponse);
+  // These are IO helpers for streaming
+  rpc Read(vagrant.io.ReadRequest) returns (vagrant.io.ReadResponse);
+  rpc Write(vagrant.io.WriteRequest) returns (vagrant.io.WriteResponse);
 }
 
 service HostCapabilities {
   rpc HostCapabilities(vagrant.common.NullRequest) returns (CapabilitiesResponse);
   rpc HostCapability(HostCapabilityRequest) returns (HostCapabilityResponse);
+  // These are IO helpers for streaming
+  rpc Read(vagrant.io.ReadRequest) returns (vagrant.io.ReadResponse);
+  rpc Write(vagrant.io.WriteRequest) returns (vagrant.io.WriteResponse);
 }
 
 service ProviderCapabilities {
   rpc ProviderCapabilities(vagrant.common.NullRequest) returns (ProviderCapabilitiesResponse);
   rpc ProviderCapability(ProviderCapabilityRequest) returns (ProviderCapabilityResponse);
+  // These are IO helpers for streaming
+  rpc Read(vagrant.io.ReadRequest) returns (vagrant.io.ReadResponse);
+  rpc Write(vagrant.io.WriteRequest) returns (vagrant.io.WriteResponse);
 }

ext/go-plugin/vagrant/plugin/proto/vagrant_config/config.pb.go

@@ -7,6 +7,7 @@ import proto "github.com/golang/protobuf/proto"
 import fmt "fmt"
 import math "math"
 import vagrant_common "github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin/proto/vagrant_common"
+import vagrant_io "github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin/proto/vagrant_io"
 
 import (
 	context "golang.org/x/net/context"
@@ -356,6 +357,9 @@ type ConfigClient interface {
 	ConfigLoad(ctx context.Context, in *LoadRequest, opts ...grpc.CallOption) (*LoadResponse, error)
 	ConfigValidate(ctx context.Context, in *ValidateRequest, opts ...grpc.CallOption) (*ValidateResponse, error)
 	ConfigFinalize(ctx context.Context, in *FinalizeRequest, opts ...grpc.CallOption) (*FinalizeResponse, error)
+	// These are IO helpers for streaming
+	Read(ctx context.Context, in *vagrant_io.ReadRequest, opts ...grpc.CallOption) (*vagrant_io.ReadResponse, error)
+	Write(ctx context.Context, in *vagrant_io.WriteRequest, opts ...grpc.CallOption) (*vagrant_io.WriteResponse, error)
 }
 
 type configClient struct {
@@ -402,12 +406,33 @@ func (c *configClient) ConfigFinalize(ctx context.Context, in *FinalizeRequest,
 	return out, nil
 }
 
+func (c *configClient) Read(ctx context.Context, in *vagrant_io.ReadRequest, opts ...grpc.CallOption) (*vagrant_io.ReadResponse, error) {
+	out := new(vagrant_io.ReadResponse)
+	err := c.cc.Invoke(ctx, "/vagrant.config.Config/Read", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *configClient) Write(ctx context.Context, in *vagrant_io.WriteRequest, opts ...grpc.CallOption) (*vagrant_io.WriteResponse, error) {
+	out := new(vagrant_io.WriteResponse)
+	err := c.cc.Invoke(ctx, "/vagrant.config.Config/Write", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 // ConfigServer is the server API for Config service.
 type ConfigServer interface {
 	ConfigAttributes(context.Context, *vagrant_common.NullRequest) (*AttributesResponse, error)
 	ConfigLoad(context.Context, *LoadRequest) (*LoadResponse, error)
 	ConfigValidate(context.Context, *ValidateRequest) (*ValidateResponse, error)
 	ConfigFinalize(context.Context, *FinalizeRequest) (*FinalizeResponse, error)
+	// These are IO helpers for streaming
+	Read(context.Context, *vagrant_io.ReadRequest) (*vagrant_io.ReadResponse, error)
+	Write(context.Context, *vagrant_io.WriteRequest) (*vagrant_io.WriteResponse, error)
 }
 
 func RegisterConfigServer(s *grpc.Server, srv ConfigServer) {
@@ -486,6 +511,42 @@ func _Config_ConfigFinalize_Handler(srv interface{}, ctx context.Context, dec fu
 	return interceptor(ctx, in, info, handler)
 }
 
+func _Config_Read_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(vagrant_io.ReadRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(ConfigServer).Read(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/vagrant.config.Config/Read",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(ConfigServer).Read(ctx, req.(*vagrant_io.ReadRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _Config_Write_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(vagrant_io.WriteRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(ConfigServer).Write(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/vagrant.config.Config/Write",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(ConfigServer).Write(ctx, req.(*vagrant_io.WriteRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
 var _Config_serviceDesc = grpc.ServiceDesc{
 	ServiceName: "vagrant.config.Config",
 	HandlerType: (*ConfigServer)(nil),
@@ -506,6 +567,14 @@ var _Config_serviceDesc = grpc.ServiceDesc{
 			MethodName: "ConfigFinalize",
 			Handler:    _Config_ConfigFinalize_Handler,
 		},
+		{
+			MethodName: "Read",
+			Handler:    _Config_Read_Handler,
+		},
+		{
+			MethodName: "Write",
+			Handler:    _Config_Write_Handler,
+		},
 	},
 	Streams:  []grpc.StreamDesc{},
 	Metadata: "vagrant_config/config.proto",
@@ -514,28 +583,31 @@ var _Config_serviceDesc = grpc.ServiceDesc{
 func init() { proto.RegisterFile("vagrant_config/config.proto", fileDescriptor_952629f1a9a7438c) }
 
 var fileDescriptor_952629f1a9a7438c = []byte{
-	// 363 bytes of a gzipped FileDescriptorProto
+	// 415 bytes of a gzipped FileDescriptorProto
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-	0x10, 0x82, 0xff, 0x33, 0xa2, 0x88, 0xd3, 0xd2, 0x1a, 0xbd, 0xf7, 0x2e, 0x60, 0xd7, 0x48, 0x6c,
+	0x7c, 0xe8, 0x69, 0xc3, 0xf9, 0x0e, 0xef, 0xce, 0x39, 0x09, 0x3c, 0x7a, 0x57, 0xd0, 0x5c, 0x22,
-	0xa1, 0x35, 0x9a, 0x06, 0xf8, 0x15, 0xf4, 0x9f, 0x49, 0xc2, 0x66, 0x44, 0xd1, 0x0d, 0x05, 0x90,
+	0x04, 0xbd, 0x80, 0x48, 0x62, 0x75, 0x94, 0x46, 0x9d, 0x9d, 0x3f, 0xf0, 0x5e, 0x4b, 0x4c, 0xa1,
-	0x03, 0xdb, 0x29, 0x09, 0x63, 0xc6, 0xa9, 0xbd, 0x5e, 0x86, 0xde, 0x35, 0x0c, 0x2a, 0x80, 0x2d,
+	0x16, 0xcd, 0x1e, 0xf8, 0x3f, 0x18, 0x5f, 0x92, 0x98, 0x05, 0x44, 0xd2, 0x03, 0x05, 0x90, 0x05,
-	0xbf, 0x0f, 0x1d, 0x4d, 0x2f, 0xff, 0x68, 0xa3, 0x86, 0x27, 0x9c, 0x40, 0xff, 0x8e, 0x71, 0x92,
+	0x6f, 0x13, 0xe2, 0x47, 0x2c, 0xa5, 0x26, 0xbd, 0x34, 0x9d, 0xff, 0x30, 0xa9, 0x00, 0xa6, 0xfc,
-	0xb0, 0xaf, 0x4d, 0x4f, 0xf0, 0x2e, 0x61, 0x50, 0xc9, 0xfe, 0xfa, 0xcf, 0xb3, 0xef, 0x36, 0x74,
+	0x47, 0x18, 0x28, 0x7a, 0xf9, 0x46, 0x63, 0xed, 0xb9, 0xc2, 0x0f, 0x18, 0x9f, 0xb0, 0x94, 0xc4,
-	0x6e, 0xb5, 0xf1, 0x68, 0x02, 0x03, 0xb3, 0xab, 0x1c, 0x42, 0x43, 0xbf, 0x9a, 0x0e, 0x6d, 0xe3,
+	0xec, 0xf1, 0xd0, 0x15, 0x9c, 0x05, 0x4c, 0x2a, 0xd9, 0x4b, 0xdf, 0xf9, 0xeb, 0xa9, 0x0b, 0x83,
-	0x53, 0x91, 0x24, 0xf6, 0x35, 0xae, 0xe7, 0x2f, 0x8f, 0x8e, 0xbf, 0xc6, 0xda, 0x7b, 0x00, 0x03,
+	0x63, 0xb5, 0x4d, 0x68, 0x09, 0x13, 0x7d, 0xaa, 0x26, 0x84, 0xa6, 0x6e, 0xb5, 0x72, 0x6a, 0x37,
-	0xfd, 0xf5, 0x61, 0x09, 0xa7, 0x6f, 0x2c, 0x18, 0xe8, 0x1e, 0xac, 0x3f, 0xb4, 0xa0, 0x09, 0xf4,
+	0x2e, 0x8a, 0x38, 0x36, 0xb7, 0xb1, 0x1d, 0x77, 0x77, 0x1f, 0xdd, 0x96, 0xd1, 0x9e, 0x02, 0x68,
-	0x0c, 0xa8, 0xec, 0x2a, 0x3a, 0xaa, 0xeb, 0x6b, 0x86, 0xb9, 0xa3, 0x66, 0x41, 0x1d, 0x5a, 0x76,
+	0xe8, 0x7a, 0x0e, 0x3b, 0x38, 0x95, 0xb1, 0x35, 0x40, 0xfb, 0x4b, 0x7b, 0xd0, 0x80, 0x96, 0x30,
-	0x70, 0x15, 0x5a, 0xb3, 0x60, 0x15, 0x5a, 0x6f, 0xfe, 0xb4, 0xa3, 0x47, 0xfd, 0xfc, 0x27, 0x00,
+	0xd2, 0xa0, 0xb2, 0xab, 0xe8, 0x5b, 0x5d, 0x5f, 0x1b, 0x98, 0x3d, 0xdb, 0x2f, 0xa8, 0x43, 0xcb,
-	0x00, 0xff, 0xff, 0xe0, 0x00, 0xbf, 0x51, 0x76, 0x03, 0x00, 0x00,
+	0x0e, 0x36, 0xa1, 0xb5, 0x11, 0x34, 0xa1, 0x8d, 0xe6, 0xff, 0x85, 0x9e, 0x47, 0x49, 0x80, 0x3e,
+	0x6d, 0x94, 0x8c, 0xbb, 0x6b, 0x4f, 0x89, 0xb0, 0x9a, 0x01, 0x93, 0xba, 0x80, 0xfe, 0x95, 0x60,
+	0x92, 0xa2, 0x1d, 0x89, 0x72, 0x95, 0xc9, 0x9f, 0x5b, 0x22, 0x3a, 0x7b, 0x35, 0x50, 0xff, 0xd8,
+	0xef, 0xe7, 0x00, 0x00, 0x00, 0xff, 0xff, 0x5f, 0x44, 0xad, 0xc6, 0x44, 0x04, 0x00, 0x00,
 }

ext/go-plugin/vagrant/plugin/proto/vagrant_config/config.proto

@@ -2,6 +2,7 @@ syntax = "proto3";
 package vagrant.config;
 
 import "github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin/proto/vagrant_common/common.proto";
+import "github.com/hashicorp/vagrant/ext/go-plugin/vagrant/plugin/proto/vagrant_io/io.proto";
 
 message AttributesResponse {
   repeated string attributes = 1;
@@ -41,4 +42,7 @@ service Config {
   rpc ConfigLoad(LoadRequest) returns (LoadResponse);
   rpc ConfigValidate(ValidateRequest) returns (ValidateResponse);
   rpc ConfigFinalize(FinalizeRequest) returns (FinalizeResponse);
+  // These are IO helpers for streaming
+  rpc Read(vagrant.io.ReadRequest) returns (vagrant.io.ReadResponse);
+  rpc Write(vagrant.io.WriteRequest) returns (vagrant.io.WriteResponse);
 }

ext/go-plugin/vagrant/plugin/provider.go

@@ -2,6 +2,7 @@ package plugin
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
 
 	"google.golang.org/grpc"
@@ -110,19 +111,26 @@ func (c *GRPCProviderClient) MachineIdChanged(m *vagrant.Machine) (err error) {
 	return
 }
 
-func (c *GRPCProviderClient) RunAction(actName string, runData string, m *vagrant.Machine) (r string, err error) {
+func (c *GRPCProviderClient) RunAction(actName string, args interface{}, m *vagrant.Machine) (r interface{}, err error) {
 	machData, err := vagrant.DumpMachine(m)
 	if err != nil {
 		return
 	}
+	runData, err := json.Marshal(args)
+	if err != nil {
+		return
+	}
 	resp, err := c.client.RunAction(context.Background(), &vagrant_provider.RunActionRequest{
 		Name:    actName,
-		Data:    runData,
+		Data:    string(runData),
 		Machine: machData})
 	if err != nil {
 		return
 	}
-	r = resp.Data
+	err = json.Unmarshal([]byte(resp.Data), &r)
+	if err != nil {
+		return
+	}
 	if resp.Error != "" {
 		err = errors.New(resp.Error)
 	}
@@ -178,10 +186,6 @@ func (c *GRPCProviderClient) Name() string {
 	return resp.Name
 }
 
-func (p *ProviderPlugin) GRPCServer(broker *go_plugin.GRPCBroker, s *grpc.Server) error {
-	return nil
-}
-
 func (p *ProviderPlugin) GRPCClient(ctx context.Context, broker *go_plugin.GRPCBroker, c *grpc.ClientConn) (interface{}, error) {
 	client := vagrant_provider.NewProviderClient(c)
 	return &GRPCProviderClient{
@@ -199,12 +203,7 @@ func (p *ProviderPlugin) GRPCClient(ctx context.Context, broker *go_plugin.GRPCB
 	}, nil
 }
 
-type GRPCProviderPlugin struct {
+func (p *ProviderPlugin) GRPCServer(broker *go_plugin.GRPCBroker, s *grpc.Server) error {
-	ProviderPlugin
-	Impl Provider
-}
-
-func (p *GRPCProviderPlugin) GRPCServer(broker *go_plugin.GRPCBroker, s *grpc.Server) error {
 	p.Impl.Init()
 	vagrant_provider.RegisterProviderServer(s, &GRPCProviderServer{
 		Impl: p.Impl,
@@ -221,10 +220,6 @@ func (p *GRPCProviderPlugin) GRPCServer(broker *go_plugin.GRPCBroker, s *grpc.Se
 	return nil
 }
 
-func (p *GRPCProviderPlugin) GRPCClient(context.Context, *go_plugin.GRPCBroker, *grpc.ClientConn) (interface{}, error) {
-	return nil, nil
-}
-
 type GRPCProviderServer struct {
 	GRPCIOServer
 	GRPCConfigServer
@@ -257,12 +252,21 @@ func (s *GRPCProviderServer) RunAction(ctx context.Context, req *vagrant_provide
 		resp.Error = e.Error()
 		return
 	}
-	r, e := s.Impl.RunAction(req.Name, req.Data, m)
+	var args interface{}
+	err = json.Unmarshal([]byte(req.Data), &args)
+	if err != nil {
+		return
+	}
+	r, e := s.Impl.RunAction(req.Name, args, m)
 	if e != nil {
 		resp.Error = e.Error()
 		return
 	}
-	resp.Data = r
+	result, err := json.Marshal(r)
+	if err != nil {
+		return
+	}
+	resp.Data = string(result)
 	return
 }
 

ext/go-plugin/vagrant/plugin/provider_test.go

@@ -0,0 +1,313 @@
+package plugin
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/hashicorp/go-plugin"
+	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant"
+)
+
+func TestProvider_Action(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &ProviderPlugin{Impl: &MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	resp, err := impl.Action("valid", &vagrant.Machine{})
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	if resp[0] != "self::DoTask" {
+		t.Errorf("%s != self::DoTask", resp[0])
+	}
+}
+
+func TestProvider_Action_invalid(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &ProviderPlugin{Impl: &MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	_, err = impl.Action("invalid", &vagrant.Machine{})
+	if err == nil {
+		t.Errorf("illegal action")
+	}
+}
+
+func TestProvider_IsInstalled(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &ProviderPlugin{Impl: &MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	installed, err := impl.IsInstalled(&vagrant.Machine{})
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	if !installed {
+		t.Errorf("bad result")
+	}
+}
+
+func TestProvider_IsUsable(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &ProviderPlugin{Impl: &MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	usable, err := impl.IsUsable(&vagrant.Machine{})
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	if !usable {
+		t.Errorf("bad result")
+	}
+}
+
+func TestProvider_MachineIdChanged(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &ProviderPlugin{Impl: &MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	err = impl.MachineIdChanged(&vagrant.Machine{})
+	if err != nil {
+		t.Errorf("err: %s", err)
+	}
+}
+
+func TestProvider_Name(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &ProviderPlugin{Impl: &MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	resp := impl.Name()
+	if resp != "mock_provider" {
+		t.Errorf("%s != mock_provider", resp)
+	}
+}
+
+func TestProvider_RunAction(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &ProviderPlugin{Impl: &MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	args := []string{"test_arg", "other_arg"}
+	m := &vagrant.Machine{}
+
+	resp, err := impl.RunAction("valid", args, m)
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+
+	result := resp.([]interface{})
+	if result[0] != "valid" {
+		t.Errorf("%s != valid", result[0])
+	}
+	if result[1] != "test_arg" {
+		t.Errorf("%s != test_arg", result[1])
+	}
+}
+
+func TestProvider_RunAction_invalid(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &ProviderPlugin{Impl: &MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	args := []string{"test_arg", "other_arg"}
+	m := &vagrant.Machine{}
+
+	_, err = impl.RunAction("invalid", args, m)
+	if err == nil {
+		t.Fatalf("illegal action run")
+	}
+}
+
+func TestProvider_SshInfo(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &ProviderPlugin{Impl: &MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	resp, err := impl.SshInfo(&vagrant.Machine{})
+	if err != nil {
+		t.Fatalf("invalid resp: %s", err)
+	}
+
+	if resp.Host != "localhost" {
+		t.Errorf("%s != localhost", resp.Host)
+	}
+	if resp.Port != 2222 {
+		t.Errorf("%d != 2222", resp.Port)
+	}
+}
+
+func TestProvider_State(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &ProviderPlugin{Impl: &MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	resp, err := impl.State(&vagrant.Machine{})
+	if err != nil {
+		t.Fatalf("invalid resp: %s", err)
+	}
+
+	if resp.Id != "default" {
+		t.Errorf("%s != default", resp.Id)
+	}
+	if resp.ShortDesc != "running" {
+		t.Errorf("%s != running", resp.ShortDesc)
+	}
+}
+
+func TestProvider_Info(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &ProviderPlugin{Impl: &MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	resp := impl.Info()
+
+	if resp.Description != "Custom" {
+		t.Errorf("%s != Custom", resp.Description)
+	}
+	if resp.Priority != 10 {
+		t.Errorf("%d != 10", resp.Priority)
+	}
+}
+
+func TestProvider_MachineUI_output(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"provider": &ProviderPlugin{Impl: &MockProvider{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("provider")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(Provider)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	go func() {
+		_, err = impl.RunAction("send_output", nil, &vagrant.Machine{})
+		if err != nil {
+			t.Fatalf("bad resp: %s", err)
+		}
+	}()
+
+	resp, err := impl.Read("stdout")
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+
+	if !strings.Contains(resp, "test_output_p") {
+		t.Errorf("%s !~ test_output_p", resp)
+	}
+}

ext/go-plugin/vagrant/plugin/synced_folder.go

@@ -31,7 +31,7 @@ type GRPCSyncedFolderClient struct {
 	client vagrant_folder.SyncedFolderClient
 }
 
-func (c *GRPCSyncedFolderClient) Cleanup(m *vagrant.Machine, o *vagrant.FolderOptions) (err error) {
+func (c *GRPCSyncedFolderClient) Cleanup(m *vagrant.Machine, o vagrant.FolderOptions) (err error) {
 	machine, err := vagrant.DumpMachine(m)
 	if err != nil {
 		return
@@ -52,7 +52,7 @@ func (c *GRPCSyncedFolderClient) Cleanup(m *vagrant.Machine, o *vagrant.FolderOp
 	return
 }
 
-func (c *GRPCSyncedFolderClient) Disable(m *vagrant.Machine, f *vagrant.FolderList, o *vagrant.FolderOptions) (err error) {
+func (c *GRPCSyncedFolderClient) Disable(m *vagrant.Machine, f vagrant.FolderList, o vagrant.FolderOptions) (err error) {
 	machine, err := vagrant.DumpMachine(m)
 	if err != nil {
 		return
@@ -78,7 +78,7 @@ func (c *GRPCSyncedFolderClient) Disable(m *vagrant.Machine, f *vagrant.FolderLi
 	return
 }
 
-func (c *GRPCSyncedFolderClient) Enable(m *vagrant.Machine, f *vagrant.FolderList, o *vagrant.FolderOptions) (err error) {
+func (c *GRPCSyncedFolderClient) Enable(m *vagrant.Machine, f vagrant.FolderList, o vagrant.FolderOptions) (err error) {
 	machine, err := vagrant.DumpMachine(m)
 	if err != nil {
 		return
@@ -136,7 +136,7 @@ func (c *GRPCSyncedFolderClient) Name() string {
 	return resp.Name
 }
 
-func (c *GRPCSyncedFolderClient) Prepare(m *vagrant.Machine, f *vagrant.FolderList, o *vagrant.FolderOptions) (err error) {
+func (c *GRPCSyncedFolderClient) Prepare(m *vagrant.Machine, f vagrant.FolderList, o vagrant.FolderOptions) (err error) {
 	machine, err := vagrant.DumpMachine(m)
 	if err != nil {
 		return
@@ -171,7 +171,7 @@ type GRPCSyncedFolderServer struct {
 
 func (s *GRPCSyncedFolderServer) Cleanup(ctx context.Context, req *vagrant_folder.CleanupRequest) (resp *vagrant_common.EmptyResponse, err error) {
 	resp = &vagrant_common.EmptyResponse{}
-	machine, err := vagrant.LoadMachine(req.Machine, nil)
+	machine, err := vagrant.LoadMachine(req.Machine, s.Impl)
 	if err != nil {
 		return
 	}
@@ -180,7 +180,7 @@ func (s *GRPCSyncedFolderServer) Cleanup(ctx context.Context, req *vagrant_folde
 	if err != nil {
 		return
 	}
-	e := s.Impl.Cleanup(machine, &options)
+	e := s.Impl.Cleanup(machine, options)
 	if e != nil {
 		resp.Error = e.Error()
 	}
@@ -189,7 +189,7 @@ func (s *GRPCSyncedFolderServer) Cleanup(ctx context.Context, req *vagrant_folde
 
 func (s *GRPCSyncedFolderServer) Disable(ctx context.Context, req *vagrant_folder.Request) (resp *vagrant_common.EmptyResponse, err error) {
 	resp = &vagrant_common.EmptyResponse{}
-	machine, err := vagrant.LoadMachine(req.Machine, nil)
+	machine, err := vagrant.LoadMachine(req.Machine, s.Impl)
 	if err != nil {
 		return
 	}
@@ -203,7 +203,7 @@ func (s *GRPCSyncedFolderServer) Disable(ctx context.Context, req *vagrant_folde
 	if err != nil {
 		return
 	}
-	e := s.Impl.Disable(machine, &folders, &options)
+	e := s.Impl.Disable(machine, folders, options)
 	if e != nil {
 		resp.Error = e.Error()
 	}
@@ -212,7 +212,7 @@ func (s *GRPCSyncedFolderServer) Disable(ctx context.Context, req *vagrant_folde
 
 func (s *GRPCSyncedFolderServer) Enable(ctx context.Context, req *vagrant_folder.Request) (resp *vagrant_common.EmptyResponse, err error) {
 	resp = &vagrant_common.EmptyResponse{}
-	machine, err := vagrant.LoadMachine(req.Machine, nil)
+	machine, err := vagrant.LoadMachine(req.Machine, s.Impl)
 	if err != nil {
 		return
 	}
@@ -226,7 +226,7 @@ func (s *GRPCSyncedFolderServer) Enable(ctx context.Context, req *vagrant_folder
 	if err != nil {
 		return
 	}
-	e := s.Impl.Enable(machine, &folders, &options)
+	e := s.Impl.Enable(machine, folders, options)
 	if e != nil {
 		resp.Error = e.Error()
 	}
@@ -242,7 +242,7 @@ func (s *GRPCSyncedFolderServer) Info(ctx context.Context, req *vagrant_common.N
 
 func (s *GRPCSyncedFolderServer) IsUsable(ctx context.Context, req *vagrant_common.EmptyRequest) (resp *vagrant_common.IsResponse, err error) {
 	resp = &vagrant_common.IsResponse{}
-	machine, err := vagrant.LoadMachine(req.Machine, nil)
+	machine, err := vagrant.LoadMachine(req.Machine, s.Impl)
 	if err != nil {
 		return
 	}
@@ -260,7 +260,7 @@ func (s *GRPCSyncedFolderServer) Name(ctx context.Context, req *vagrant_common.N
 
 func (s *GRPCSyncedFolderServer) Prepare(ctx context.Context, req *vagrant_folder.Request) (resp *vagrant_common.EmptyResponse, err error) {
 	resp = &vagrant_common.EmptyResponse{}
-	machine, err := vagrant.LoadMachine(req.Machine, nil)
+	machine, err := vagrant.LoadMachine(req.Machine, s.Impl)
 	if err != nil {
 		return
 	}
@@ -274,7 +274,7 @@ func (s *GRPCSyncedFolderServer) Prepare(ctx context.Context, req *vagrant_folde
 	if err != nil {
 		return
 	}
-	e := s.Impl.Prepare(machine, &folders, &options)
+	e := s.Impl.Prepare(machine, folders, options)
 	if e != nil {
 		resp.Error = e.Error()
 	}
@@ -282,10 +282,27 @@ func (s *GRPCSyncedFolderServer) Prepare(ctx context.Context, req *vagrant_folde
 }
 
 func (f *SyncedFolderPlugin) GRPCServer(broker *go_plugin.GRPCBroker, s *grpc.Server) error {
-	vagrant_folder.RegisterSyncedFolderServer(s, &GRPCSyncedFolderServer{Impl: f.Impl})
+	f.Impl.Init()
+	vagrant_folder.RegisterSyncedFolderServer(s,
+		&GRPCSyncedFolderServer{
+			Impl: f.Impl,
+			GRPCIOServer: GRPCIOServer{
+				Impl: f.Impl},
+			GRPCGuestCapabilitiesServer: GRPCGuestCapabilitiesServer{
+				Impl: f.Impl},
+			GRPCHostCapabilitiesServer: GRPCHostCapabilitiesServer{
+				Impl: f.Impl}})
 	return nil
 }
 
 func (f *SyncedFolderPlugin) GRPCClient(ctx context.Context, broker *go_plugin.GRPCBroker, c *grpc.ClientConn) (interface{}, error) {
-	return &GRPCSyncedFolderClient{client: vagrant_folder.NewSyncedFolderClient(c)}, nil
+	client := vagrant_folder.NewSyncedFolderClient(c)
+	return &GRPCSyncedFolderClient{
+		GRPCIOClient: GRPCIOClient{
+			client: client},
+		GRPCGuestCapabilitiesClient: GRPCGuestCapabilitiesClient{
+			client: client},
+		GRPCHostCapabilitiesClient: GRPCHostCapabilitiesClient{
+			client: client},
+		client: client}, nil
 }

ext/go-plugin/vagrant/plugin/synced_folder_test.go

@@ -0,0 +1,368 @@
+package plugin
+
+import (
+	"errors"
+	"strings"
+	"testing"
+
+	"github.com/hashicorp/go-plugin"
+	"github.com/hashicorp/vagrant/ext/go-plugin/vagrant"
+)
+
+type MockSyncedFolder struct {
+	Core
+	vagrant.NoGuestCapabilities
+	vagrant.NoHostCapabilities
+}
+
+func (s *MockSyncedFolder) Cleanup(m *vagrant.Machine, opts vagrant.FolderOptions) error {
+	if opts != nil {
+		err, _ := opts["error"].(bool)
+		ui, _ := opts["ui"].(bool)
+		if err {
+			return errors.New("cleanup error")
+		}
+		if ui {
+			m.UI.Say("test_output_sf")
+			return nil
+		}
+	}
+	return nil
+}
+
+func (s *MockSyncedFolder) Disable(m *vagrant.Machine, f vagrant.FolderList, opts vagrant.FolderOptions) error {
+	if opts != nil && opts["error"].(bool) {
+		return errors.New("disable error")
+	}
+	return nil
+}
+
+func (s *MockSyncedFolder) Enable(m *vagrant.Machine, f vagrant.FolderList, opts vagrant.FolderOptions) error {
+	if opts != nil && opts["error"].(bool) {
+		return errors.New("enable error")
+	}
+	return nil
+}
+
+func (s *MockSyncedFolder) Info() *vagrant.SyncedFolderInfo {
+	return &vagrant.SyncedFolderInfo{
+		Description: "mock_folder",
+		Priority:    100}
+}
+
+func (s *MockSyncedFolder) IsUsable(m *vagrant.Machine) (bool, error) {
+	return true, nil
+}
+
+func (s *MockSyncedFolder) Name() string {
+	return "mock_folder"
+}
+
+func (s *MockSyncedFolder) Prepare(m *vagrant.Machine, f vagrant.FolderList, opts vagrant.FolderOptions) error {
+	if opts != nil && opts["error"].(bool) {
+		return errors.New("prepare error")
+	}
+	return nil
+}
+
+func TestSyncedFolder_Cleanup(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"folder": &SyncedFolderPlugin{Impl: &MockSyncedFolder{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("folder")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(SyncedFolder)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	err = impl.Cleanup(&vagrant.Machine{}, nil)
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+}
+
+func TestSyncedFolder_Cleanup_error(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"folder": &SyncedFolderPlugin{Impl: &MockSyncedFolder{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("folder")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(SyncedFolder)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	args := map[string]interface{}{
+		"error": true}
+
+	err = impl.Cleanup(&vagrant.Machine{}, args)
+	if err == nil {
+		t.Fatalf("illegal cleanup")
+	}
+	if err.Error() != "cleanup error" {
+		t.Errorf("%s != cleanup error", err.Error())
+	}
+}
+
+func TestSyncedFolder_Disable(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"folder": &SyncedFolderPlugin{Impl: &MockSyncedFolder{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("folder")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(SyncedFolder)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	err = impl.Disable(&vagrant.Machine{}, nil, nil)
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+}
+
+func TestSyncedFolder_Disable_error(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"folder": &SyncedFolderPlugin{Impl: &MockSyncedFolder{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("folder")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(SyncedFolder)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	folders := map[string]interface{}{
+		"folder_name": "options"}
+	args := map[string]interface{}{
+		"error": true}
+
+	err = impl.Disable(&vagrant.Machine{}, folders, args)
+	if err == nil {
+		t.Fatalf("illegal disable")
+	}
+	if err.Error() != "disable error" {
+		t.Errorf("%s != disable error", err.Error())
+	}
+}
+
+func TestSyncedFolder_Enable(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"folder": &SyncedFolderPlugin{Impl: &MockSyncedFolder{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("folder")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(SyncedFolder)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	err = impl.Enable(&vagrant.Machine{}, nil, nil)
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+}
+
+func TestSyncedFolder_Enable_error(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"folder": &SyncedFolderPlugin{Impl: &MockSyncedFolder{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("folder")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(SyncedFolder)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	folders := map[string]interface{}{
+		"folder_name": "options"}
+	args := map[string]interface{}{
+		"error": true}
+
+	err = impl.Enable(&vagrant.Machine{}, folders, args)
+	if err == nil {
+		t.Fatalf("illegal enable")
+	}
+	if err.Error() != "enable error" {
+		t.Errorf("%s != enable error", err.Error())
+	}
+}
+
+func TestSyncedFolder_Prepare(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"folder": &SyncedFolderPlugin{Impl: &MockSyncedFolder{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("folder")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(SyncedFolder)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	err = impl.Prepare(&vagrant.Machine{}, nil, nil)
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+}
+
+func TestSyncedFolder_Prepare_error(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"folder": &SyncedFolderPlugin{Impl: &MockSyncedFolder{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("folder")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(SyncedFolder)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	folders := map[string]interface{}{
+		"folder_name": "options"}
+	args := map[string]interface{}{
+		"error": true}
+
+	err = impl.Prepare(&vagrant.Machine{}, folders, args)
+	if err == nil {
+		t.Fatalf("illegal prepare")
+	}
+	if err.Error() != "prepare error" {
+		t.Errorf("%s != prepare error", err.Error())
+	}
+}
+
+func TestSyncedFolder_Info(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"folder": &SyncedFolderPlugin{Impl: &MockSyncedFolder{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("folder")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(SyncedFolder)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	resp := impl.Info()
+	if resp == nil {
+		t.Fatalf("bad resp")
+	}
+
+	if resp.Description != "mock_folder" {
+		t.Errorf("%s != mock_folder", resp.Description)
+	}
+	if resp.Priority != 100 {
+		t.Errorf("%d != 100", resp.Priority)
+	}
+}
+
+func TestSyncedFolder_IsUsable(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"folder": &SyncedFolderPlugin{Impl: &MockSyncedFolder{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("folder")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(SyncedFolder)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	resp, err := impl.IsUsable(&vagrant.Machine{})
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	if !resp {
+		t.Errorf("bad result")
+	}
+}
+
+func TestSyncedFolder_Name(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"folder": &SyncedFolderPlugin{Impl: &MockSyncedFolder{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("folder")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(SyncedFolder)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	resp := impl.Name()
+	if resp != "mock_folder" {
+		t.Errorf("%s != mock_folder", resp)
+	}
+}
+
+func TestSyncedFolder_MachineUI_output(t *testing.T) {
+	client, server := plugin.TestPluginGRPCConn(t, map[string]plugin.Plugin{
+		"folder": &SyncedFolderPlugin{Impl: &MockSyncedFolder{}}})
+	defer server.Stop()
+	defer client.Close()
+
+	raw, err := client.Dispense("folder")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	impl, ok := raw.(SyncedFolder)
+	if !ok {
+		t.Fatalf("bad %#v", raw)
+	}
+
+	go func() {
+		err := impl.Cleanup(&vagrant.Machine{}, map[string]interface{}{"ui": true})
+		if err != nil {
+			t.Fatalf("bad resp: %s", err)
+		}
+	}()
+
+	resp, err := impl.Read("stdout")
+	if err != nil {
+		t.Fatalf("bad resp: %s", err)
+	}
+	if !strings.Contains(resp, "test_output") {
+		t.Errorf("%s !~ test_output", resp)
+	}
+}

ext/go-plugin/vagrant/provider.go

@@ -7,7 +7,7 @@ type Provider interface {
 	IsUsable(machData *Machine) (bool, error)
 	MachineIdChanged(machData *Machine) error
 	Name() string
-	RunAction(actionName string, data string, machData *Machine) (string, error)
+	RunAction(actionName string, args interface{}, machData *Machine) (interface{}, error)
 	SshInfo(machData *Machine) (*SshInfo, error)
 	State(machData *Machine) (*MachineState, error)
 

ext/go-plugin/vagrant/response.go

@@ -1,20 +0,0 @@
-package vagrant
-
-import (
-	"encoding/json"
-	"fmt"
-)
-
-type Response struct {
-	Error  error       `json:"error"`
-	Result interface{} `json:"result"`
-}
-
-// Serialize the response into a JSON string
-func (r Response) Dump() string {
-	result, err := json.Marshal(r)
-	if err != nil {
-		return fmt.Sprintf(`{"error": "failed to encode response - %s"}`, err)
-	}
-	return string(result[:])
-}

ext/go-plugin/vagrant/synced_folder.go

@@ -9,13 +9,13 @@ type SyncedFolderInfo struct {
 }
 
 type SyncedFolder interface {
-	Cleanup(m *Machine, opts *FolderOptions) error
+	Cleanup(m *Machine, opts FolderOptions) error
-	Disable(m *Machine, f *FolderList, opts *FolderOptions) error
+	Disable(m *Machine, f FolderList, opts FolderOptions) error
-	Enable(m *Machine, f *FolderList, opts *FolderOptions) error
+	Enable(m *Machine, f FolderList, opts FolderOptions) error
 	Info() *SyncedFolderInfo
 	IsUsable(m *Machine) (bool, error)
 	Name() string
-	Prepare(m *Machine, f *FolderList, opts *FolderOptions) error
+	Prepare(m *Machine, f FolderList, opts FolderOptions) error
 
 	GuestCapabilities
 	HostCapabilities

lib/vagrant/go_plugin/capability_plugin.rb

@@ -6,12 +6,12 @@ module Vagrant
     module CapabilityPlugin
       # Wrapper class for go-plugin defined capabilities
       class Capability
-        extend TypedGoPlugin
+        include TypedGoPlugin
       end
 
       # @return [Interface]
       def self.interface
-        unless @_interface
+        if !@_interface
           @_interface = Interface.new
         end
         @_interface

lib/vagrant/go_plugin/core.rb

@@ -90,12 +90,16 @@ module Vagrant
 
           # Load given data into the provided machine. This is
           # used to update the machine with data received from
-          # go-plugins
+          # go-plugins. Currently the only modification applied
+          # is an ID change.
           #
           # @param [Hash] data Machine data from go-plugin
           # @param [Vagrant::Machine] machine
           # @return [Vagrant::Machine]
           def load_machine(data, machine)
+            if data[:id] != machine.id
+              machine.id = data[:id]
+            end
             machine
           end
 
@@ -157,7 +161,7 @@ module Vagrant
 
         # @return [String]
         def name
-          go_plugin_name.to_s.capitalize.tr("_", "")
+          go_plugin_name.to_s.split("_").map(&:capitalize).join
         end
       end
 

lib/vagrant/go_plugin/manager.rb

@@ -7,10 +7,9 @@ module Vagrant
       include Util::Logger
 
       # @return [Manager]
-      def self.instance(env=nil)
+      def self.instance
-        @instance ||= self.new
+        if !@instance
-        if env
+          @instance = self.new
-          @instance.envirnoment = env
         end
         @instance
       end

lib/vagrant/go_plugin/provider_plugin.rb

@@ -60,31 +60,11 @@ module Vagrant
       # provider so that it can be interacted with normally within
       # Vagrant
       class Provider < Vagrant.plugin("2", :provider)
+        include DirectGoPlugin
+
         # @return [Vagrant::Machine]
         attr_reader :machine
 
-        # @return [String] plugin name associated to this class
-        def self.go_plugin_name
-          @go_plugin_name
-        end
-
-        # Set the plugin name for this class
-        #
-        # @param [String] n plugin name
-        # @return [String]
-        # @note can only be set once
-        def self.go_plugin_name=(n)
-          if @go_plugin_name
-            raise ArgumentError.new("Class plugin name has already been set")
-          end
-          @go_plugin_name = n
-        end
-
-        # @return [String]
-        def self.name
-          go_plugin_name.to_s.capitalize.tr("_", "")
-        end
-
         def initialize(machine)
           @machine = machine
         end
@@ -234,21 +214,6 @@ module Vagrant
           end
         end
 
-        def capability
-        end
-
-        # Check if provider has requested capability
-        #
-        # @param [String] provider_name provider name for request
-        # @param [String] capability_name name of the capability
-        # @param [Vagrant::Machine] machine instance of guest
-        # @return [Boolean]
-        def has_capability(provider_name, capability_name, machine)
-          result = load_result { _provider_has_capability(provider_name,
-            capability_name, dump_machine(machine)) }
-          result
-        end
-
         # Check if provider is installed
         #
         # @param [String] provider_name provider name for request

test/unit/vagrant/go_plugin/capability_plugin_test.rb

@@ -0,0 +1,19 @@
+require_relative "../../base"
+
+describe Vagrant::GoPlugin::CapabilityPlugin do
+  describe Vagrant::GoPlugin::CapabilityPlugin::Capability do
+    it "should be a TypedGoPlugin" do
+      expect(described_class.ancestors).to include(Vagrant::GoPlugin::TypedGoPlugin)
+    end
+  end
+
+  describe ".interface" do
+    it "should create an interface instance" do
+      expect(described_class.interface).to be_a(Vagrant::GoPlugin::CapabilityHost::Interface)
+    end
+
+    it "should cache generated interface" do
+      expect(described_class.interface).to be(described_class.interface)
+    end
+  end
+end

test/unit/vagrant/go_plugin/core_test.rb

@@ -0,0 +1,214 @@
+require_relative "../../base"
+
+describe Vagrant::GoPlugin::Core do
+  include_context "unit"
+
+  let(:subject_class) { Class.new.tap { |c| c.include(described_class) } }
+  let(:subject) { subject_class.new }
+
+  let(:name)     { "foo" }
+  let(:provider) { new_provider_mock }
+  let(:provider_cls) do
+    obj = double("provider_cls")
+    allow(obj).to receive(:new).and_return(provider)
+    obj
+  end
+  let(:provider_config) { Object.new }
+  let(:provider_name) { :test }
+  let(:provider_options) { {} }
+  let(:base)     { false }
+  let(:box) do
+    double("box",
+      name: "foo",
+      provider: :dummy,
+      version: "1.0",
+      directory: "box dir",
+      metadata: nil,
+      metadata_url: nil)
+  end
+
+  let(:config)   { env.vagrantfile.config }
+  let(:data_dir) { Pathname.new(Dir.mktmpdir("vagrant-machine-data-dir")) }
+  let(:env)      do
+    # We need to create a Vagrantfile so that this test environment
+    # has a proper root path
+    test_env.vagrantfile("")
+
+    # Create the Vagrant::Environment instance
+    test_env.create_vagrant_env
+  end
+
+  let(:test_env) { isolated_environment }
+  let(:machine) {
+    Vagrant::Machine.new(name, provider_name, provider_cls, provider_config,
+      provider_options, config, data_dir, box,
+      env, env.vagrantfile, base)
+  }
+
+  def new_provider_mock
+    double("provider").tap do |obj|
+      allow(obj).to receive(:_initialize)
+        .with(provider_name, anything).and_return(nil)
+      allow(obj).to receive(:machine_id_changed).and_return(nil)
+      allow(obj).to receive(:state).and_return(Vagrant::MachineState.new(
+        :created, "", ""))
+    end
+  end
+
+  describe "#dump_machine" do
+    it "should raise error when argument is not a Vagrant Machine" do
+      expect { subject.dump_machine(:value) }.to raise_error(TypeError)
+    end
+
+    it "should dump machine to JSON string" do
+      expect(subject.dump_machine(machine)).to be_a(String)
+    end
+
+    it "should dump machine information" do
+      val = subject.dump_machine(machine)
+      result = JSON.load(val)
+      expect(result["name"]).to eq(machine.name)
+      expect(result["provider_name"]).to eq(machine.provider_name.to_s)
+      expect(result["data_dir"]).to eq(machine.data_dir.to_s)
+    end
+
+    it "should dump box information" do
+      val = subject.dump_machine(machine)
+      result = JSON.load(val)
+      expect(result["box"]).to_not be_nil
+      expect(result["box"]["name"]).to eq("foo")
+    end
+
+    it "should dump environment information" do
+      val = subject.dump_machine(machine)
+      result = JSON.load(val)
+      expect(result["environment"]).to_not be_nil
+      expect(result["environment"]["cwd"]).to eq(machine.env.cwd.to_s)
+    end
+  end
+
+  describe "#dump_environment" do
+    it "should dump environment to Hash" do
+      expect(subject.dump_environment(env)).to be_a(Hash)
+    end
+
+    it "should include environment information" do
+      result = subject.dump_environment(env)
+      expect(result[:cwd]).to eq(env.cwd)
+      expect(result[:data_dir]).to eq(env.data_dir)
+    end
+  end
+
+  describe "#load_machine" do
+    it "should set ID if ID has changed" do
+      expect(machine).to receive(:id=).with("newid")
+      subject.load_machine({id: "newid"}, machine)
+    end
+
+    it "should not set ID if ID has not changed" do
+      expect(machine).not_to receive(:id=)
+      subject.load_machine({id: machine.id}, machine)
+    end
+  end
+end
+
+describe Vagrant::GoPlugin::DirectGoPlugin do
+  let(:subject_class) { Class.new.tap { |c| c.include(described_class) } }
+  let(:subject) { subject_class.new }
+
+  describe ".go_plugin_name" do
+    it "should return nil by default" do
+      expect(subject_class.go_plugin_name).to be_nil
+    end
+
+    it "should return assigned name when assigned" do
+      subject_class.go_plugin_name = :test
+      expect(subject_class.go_plugin_name).to eq(:test)
+    end
+  end
+
+  describe ".go_plugin_name=" do
+    it "should allow for setting the plugin name" do
+      subject_class.go_plugin_name = :test_plugin
+      expect(subject_class.go_plugin_name).to eq(:test_plugin)
+    end
+
+    it "should raise error when name has already been set" do
+      subject_class.go_plugin_name = :test_plugin
+      expect {
+        subject_class.go_plugin_name = :different_plugin
+      }.to raise_error(ArgumentError)
+    end
+  end
+
+  describe ".plugin_name" do
+    it "should proxy to .go_plugin_name" do
+      expect(subject_class).to receive(:go_plugin_name)
+      subject_class.plugin_name
+    end
+  end
+
+  describe ".name" do
+    it "should default to empty string" do
+      expect(subject_class.name).to eq("")
+    end
+
+    it "should camel case the go_plugin_name" do
+      subject_class.go_plugin_name = "test_vagrant_plugin"
+      expect(subject_class.name).to eq("TestVagrantPlugin")
+    end
+  end
+
+  describe "#plugin_name" do
+    it "should proxy to .go_plugin_name" do
+      expect(subject_class).to receive(:go_plugin_name)
+      subject.plugin_name
+    end
+  end
+end
+
+describe Vagrant::GoPlugin::TypedGoPlugin do
+  let(:subject_class) { Class.new.tap { |c| c.include(described_class) } }
+  let(:subject) { subject_class.new }
+
+  it "should include DirectGoPlugin" do
+    expect(subject_class.ancestors).to include(Vagrant::GoPlugin::DirectGoPlugin)
+  end
+
+  describe ".go_plugin_type" do
+    it "should be nil by default" do
+      expect(subject_class.go_plugin_type).to be_nil
+    end
+
+    it "should return assigned type when set" do
+      subject_class.go_plugin_type = "provider"
+      expect(subject_class.go_plugin_type).to eq("provider")
+    end
+  end
+
+  describe ".go_plugin_type=" do
+    it "should allow setting plugin type" do
+      subject_class.go_plugin_type = "test_type"
+      expect(subject_class.go_plugin_type).to eq("test_type")
+    end
+
+    it "should convert plugin type value to string" do
+      subject_class.go_plugin_type = :test_type
+      expect(subject_class.go_plugin_type).to eq("test_type")
+    end
+
+    it "should raise an error when type has already been set" do
+      subject_class.go_plugin_type = :test_type
+      expect {
+        subject_class.go_plugin_type = :different_type
+      }.to raise_error(ArgumentError)
+    end
+  end
+
+  describe "#plugin_type" do
+    it "should proxy to .go_plugin_type" do
+      expect(subject_class).to receive(:go_plugin_type)
+      subject.plugin_type
+    end
+  end
+end

test/unit/vagrant/go_plugin/interface_test.rb

@@ -0,0 +1,56 @@
+require_relative "../../base"
+
+describe Vagrant::GoPlugin::Interface do
+  before do
+    allow_any_instance_of(described_class).to receive(:_setup)
+  end
+
+  describe "#load_plugins" do
+    let(:path) { double("path", to_s: "path") }
+
+    it "should raise error if path is not a directory" do
+      expect(File).to receive(:directory?).with(path.to_s).and_return(false)
+      expect { subject.load_plugins(path) }.to raise_error(ArgumentError)
+    end
+
+    it "should load plugins if path is a directory" do
+      expect(File).to receive(:directory?).with(path.to_s).and_return(true)
+      expect(subject).to receive(:_load_plugins).with(path.to_s)
+      subject.load_plugins(path)
+    end
+  end
+
+  describe "#register_plugins" do
+    it "should load Provider and SyncedFolder plugins" do
+      expect(Vagrant::GoPlugin::ProviderPlugin).to receive_message_chain(:interface, :load!)
+      expect(Vagrant::GoPlugin::SyncedFolderPlugin).to receive_message_chain(:interface, :load!)
+      subject.register_plugins
+    end
+  end
+
+  describe "#setup" do
+    after { subject }
+
+    it "should register at_exit action" do
+      expect(Kernel).to receive(:at_exit)
+      subject
+    end
+
+    it "should run the setup action" do
+      expect_any_instance_of(described_class).to receive(:_setup)
+    end
+
+    it "should only run the setup process once" do
+      expect_any_instance_of(described_class).to receive(:_setup).once
+      expect(subject.logger).to receive(:warn)
+      subject.setup
+    end
+  end
+
+  describe "#teardown" do
+    it "should run the teardown action" do
+      expect(subject).to receive(:_teardown)
+      subject.teardown
+    end
+  end
+end

test/unit/vagrant/go_plugin/manager_test.rb

@@ -0,0 +1,148 @@
+require_relative "../../base"
+
+describe Vagrant::GoPlugin::Manager do
+  include_context "unit"
+
+  let(:env) do
+    test_env.vagrantfile("")
+    test_env.create_vagrant_env
+  end
+
+  before do
+    allow(FileUtils).to receive(:mkdir_p)
+  end
+
+  describe ".instance" do
+    it "should return instance of manager" do
+      expect(described_class.instance).to be_a(described_class)
+    end
+
+    it "should cache instance" do
+      expect(described_class.instance).to be(described_class.instance)
+    end
+  end
+
+  describe ".new" do
+    it "should create the installation directory" do
+      expect(FileUtils).to receive(:mkdir_p).with(Vagrant::GoPlugin::INSTALL_DIRECTORY)
+      subject
+    end
+
+    it "should create installation temporary directory" do
+      expect(FileUtils).to receive(:mkdir_p).with(/tmp$/)
+      subject
+    end
+
+    it "should generate user state file" do
+      expect(subject.user_file).to be_a(Vagrant::Plugin::StateFile)
+    end
+  end
+
+  describe "#globalize!" do
+    let(:entries) { [double("entry1"), double("entry2")] }
+
+    before do
+      allow(File).to receive(:directory?).and_return(false)
+      allow(Dir).to receive(:glob).and_return(entries)
+      allow(Vagrant::GoPlugin).to receive_message_chain(:interface, :register_plugins)
+    end
+
+    context "when entries are not directories" do
+      before { allow(File).to receive(:directory?).and_return(false) }
+
+      it "should not load any plugins" do
+        interface = double("interface", register_plugins: nil)
+        allow(Vagrant::GoPlugin).to receive(:interface).and_return(interface)
+        expect(interface).not_to receive(:load_plugins)
+        subject.globalize!
+      end
+    end
+
+    context "when entries are directories" do
+      before { allow(File).to receive(:directory?).and_return(true) }
+
+      it "should load all entries" do
+        expect(Vagrant::GoPlugin).to receive_message_chain(:interface, :load_plugins).with(entries.first)
+        expect(Vagrant::GoPlugin).to receive_message_chain(:interface, :load_plugins).with(entries.last)
+        subject.globalize!
+      end
+    end
+
+    it "should register plugins after loading" do
+      expect(Vagrant::GoPlugin).to receive_message_chain(:interface, :register_plugins)
+      subject.globalize!
+    end
+  end
+
+  describe "#localize!" do
+  end
+
+  describe "#install_plugin" do
+    let(:plugin_name) { "test_plugin_name" }
+    let(:remote_source) { double("remote_source") }
+    let(:downloader) { double("downloader", download!: nil) }
+
+    before do
+      allow(FileUtils).to receive(:mkdir_p)
+      allow(Dir).to receive(:mktmpdir)
+      allow(Vagrant::Util::Downloader).to receive(:new).and_return(downloader)
+      allow(Zip::File).to receive(:open)
+    end
+
+    after { subject.install_plugin(plugin_name, remote_source) }
+
+    it "should create plugin directory for plugin name" do
+      expect(FileUtils).to receive(:mkdir_p).with(/test_plugin_name$/)
+    end
+
+    it "should create a temporary directory to download and unpack" do
+      expect(Dir).to receive(:mktmpdir).with(/go-plugin/, any_args)
+    end
+
+    it "should download the remote file" do
+      expect(Dir).to receive(:mktmpdir).with(any_args).and_yield("tmpdir")
+      expect(downloader).to receive(:download!)
+    end
+
+    it "should unzip the downloaded file" do
+      expect(Dir).to receive(:mktmpdir).with(any_args).and_yield("tmpdir")
+      expect(Zip::File).to receive(:open).with(/plugin.zip/)
+    end
+
+    it "should add the plugin to the user file" do
+      expect(subject.user_file).to receive(:add_go_plugin).and_call_original
+      expect(subject.user_file.has_go_plugin?("test_plugin_name")).to be_truthy
+    end
+  end
+
+  describe "#uninstall_plugin" do
+    let(:plugin_name) { "test_plugin_name" }
+
+    before do
+      allow(File).to receive(:directory?).and_call_original
+      allow(FileUtils).to receive(:rm_rf)
+    end
+
+    after { subject.uninstall_plugin(plugin_name) }
+
+    it "should remove plugin path when installed" do
+      expect(File).to receive(:directory?).with(/test_plugin_name/).and_return(true)
+      expect(FileUtils).to receive(:rm_rf).with(/test_plugin_name/)
+    end
+
+    it "should not remove plugin path when not installed" do
+      expect(File).to receive(:directory?).with(/test_plugin_name/).and_return(false)
+      expect(FileUtils).not_to receive(:rm_rf).with(/test_plugin_name/)
+    end
+
+    it "should have plugin name removed from user file when installed" do
+      expect(File).to receive(:directory?).with(/test_plugin_name/).and_return(true)
+      expect(subject.user_file).to receive(:remove_go_plugin).with(plugin_name)
+    end
+
+    it "should have plugin name removed from user file when not installed" do
+      expect(File).to receive(:directory?).with(/test_plugin_name/).and_return(false)
+      expect(subject.user_file).to receive(:remove_go_plugin).with(plugin_name)
+    end
+  end
+end

test/unit/vagrant/go_plugin_test.rb

@@ -0,0 +1,29 @@
+require_relative "../base"
+
+describe Vagrant::GoPlugin do
+  describe "INSTALL_DIRECTORY constant" do
+    let(:subject) { described_class.const_get(:INSTALL_DIRECTORY) }
+
+    it "should be a String" do
+      expect(subject).to be_a(String)
+    end
+
+    it "should be frozen" do
+      expect(subject).to be_frozen
+    end
+
+    it "should be within the user data path" do
+      expect(subject).to start_with(Vagrant.user_data_path.to_s)
+    end
+  end
+
+  describe ".interface" do
+    it "should return an interface instance" do
+      expect(described_class.interface).to be_a(Vagrant::GoPlugin::Interface)
+    end
+
+    it "should cache the interface instance" do
+      expect(described_class.interface).to be(described_class.interface)
+    end
+  end
+end