Merge pull request #2896 from mitchellh/f-provider-caps

Provider Capabilities

lib/vagrant/machine.rb

@@ -114,6 +114,7 @@ module Vagrant
       # Initializes the provider last so that it has access to all the
       # state we setup on this machine.
       @provider = provider_cls.new(self)
+      @provider._initialize(@provider_name, self)
     end
 
     # This calls an action on the provider. The provider may or may not

lib/vagrant/plugin/v2/components.rb

@@ -49,6 +49,11 @@ module Vagrant
         # @return [Hash<Symbol, Registry>]
         attr_reader :providers
 
+        # This contains all the registered provider capabilities.
+        #
+        # @return [Hash<Symbol, Registry>]
+        attr_reader :provider_capabilities
+
         # This contains all the synced folder implementations by name.
         #
         # @return [Registry<Symbol, Array<Class, Integer>>]
@@ -65,6 +70,7 @@ module Vagrant
           @hosts   = Registry.new
           @host_capabilities = Hash.new { |h, k| h[k] = Registry.new }
           @providers = Registry.new
+          @provider_capabilities = Hash.new { |h, k| h[k] = Registry.new }
           @synced_folders = Registry.new
         end
       end

lib/vagrant/plugin/v2/manager.rb

@@ -113,7 +113,6 @@ module Vagrant
           results
         end
 
-
         # This returns all registered providers.
         #
         # @return [Hash]
@@ -125,6 +124,21 @@ module Vagrant
           end
         end
 
+        # This returns all the registered provider capabilities.
+        #
+        # @return [Hash]
+        def provider_capabilities
+          results = Hash.new { |h, k| h[k] = Registry.new }
+
+          @registered.each do |plugin|
+            plugin.components.provider_capabilities.each do |provider, caps|
+              results[provider].merge!(caps)
+            end
+          end
+
+          results
+        end
+
         # This returns all the config classes for the various providers.
         #
         # @return [Hash]

lib/vagrant/plugin/v2/plugin.rb

@@ -193,6 +193,18 @@ module Vagrant
           nil
         end
 
+        # Defines a capability for the given provider. The block should return
+        # a class/module that has a method with the capability name, ready
+        # to be executed. This means that if it is an instance method,
+        # the block should return an instance of the class.
+        #
+        # @param [String] provider The name of the provider
+        # @param [String] cap The name of the capability
+        def self.provider_capability(provider, cap, &block)
+          components.provider_capabilities[provider.to_sym].register(cap.to_sym, &block)
+          nil
+        end
+
         # Registers additional provisioners to be available.
         #
         # @param [String] name Name of the provisioner.

lib/vagrant/plugin/v2/provider.rb

@@ -1,3 +1,5 @@
+require "vagrant/capability_host"
+
 module Vagrant
   module Plugin
     module V2
@@ -5,6 +7,8 @@ module Vagrant
       # is responsible for creating compute resources to match the needs
       # of a Vagrant-configured system.
       class Provider
+        include CapabilityHost
+
         # Initialize the provider to represent the given machine.
         #
         # @param [Vagrant::Machine] machine The machine that this provider
@@ -63,6 +67,18 @@ module Vagrant
         def state
           nil
         end
+
+        # This is an internal initialize function that should never be
+        # overridden. It is used to initialize some common internal state
+        # that is used in a provider.
+        def _initialize(name, machine)
+          initialize_capabilities!(
+            name.to_sym,
+            { name.to_sym => [Class.new, nil] },
+            Vagrant.plugin("2").manager.provider_capabilities,
+            machine,
+          )
+        end
       end
     end
   end

test/unit/vagrant/machine_test.rb

@@ -7,7 +7,11 @@ describe Vagrant::Machine do
   include_context "unit"
 
   let(:name)     { "foo" }
-  let(:provider) { double("provider") }
+  let(:provider) do
+    double("provider").tap do |obj|
+      obj.stub(:_initialize => nil)
+    end
+  end
   let(:provider_cls) do
     obj = double("provider_cls")
     obj.stub(:new => provider)
@@ -48,9 +52,14 @@ describe Vagrant::Machine do
       #
       # @yield [machine] Yields the machine that the provider initialization
       #   method received so you can run additional tests on it.
-      def provider_init_test
+      def provider_init_test(instance=nil)
         received_machine = nil
 
+        if !instance
+          instance = double("instance")
+          instance.stub(:_initialize => nil)
+        end
+
         provider_cls = double("provider_cls")
         provider_cls.should_receive(:new) do |machine|
           # Store this for later so we can verify that it is the
@@ -62,7 +71,8 @@ describe Vagrant::Machine do
 
           # Yield our machine if we want to do additional tests
           yield machine if block_given?
-        end
+          true
+        end.and_return(instance)
 
         # Initialize a new machine and verify that we properly receive
         # the machine we expect.
@@ -117,6 +127,17 @@ describe Vagrant::Machine do
           machine.provider.should be_nil
         end
       end
+
+      it "should initialize the capabilities" do
+        instance = double("instance")
+        instance.should_receive(:_initialize).with do |p, m|
+          expect(p).to eq(provider_name)
+          expect(m.name).to eq(name)
+          true
+        end
+
+        provider_init_test(instance)
+      end
     end
   end
 

test/unit/vagrant/plugin/v2/plugin_test.rb

@@ -281,6 +281,16 @@ describe Vagrant::Plugin::V2::Plugin do
     end
   end
 
+  describe "provider capabilities" do
+    it "should register host capabilities" do
+      plugin = Class.new(described_class) do
+        provider_capability("foo", "bar") { "baz" }
+      end
+
+      plugin.components.provider_capabilities[:foo][:bar].should == "baz"
+    end
+  end
+
   describe "provisioners" do
     it "should register provisioner classes" do
       plugin = Class.new(described_class) do

test/unit/vagrant/plugin/v2/provider_test.rb

@@ -1,9 +1,13 @@
 require File.expand_path("../../../../base", __FILE__)
 
 describe Vagrant::Plugin::V2::Provider do
+  include_context "unit"
+
   let(:machine)  { Object.new }
   let(:instance) { described_class.new(machine) }
 
+  subject { instance }
+
   it "should return nil by default for actions" do
     instance.action(:whatever).should be_nil
   end
@@ -15,4 +19,32 @@ describe Vagrant::Plugin::V2::Provider do
   it "should return nil by default for state" do
     instance.state.should be_nil
   end
+
+  context "capabilities" do
+    before do
+      register_plugin("2") do |p|
+        p.provider_capability("bar", "foo") {}
+
+        p.provider_capability("foo", "bar") do
+          Class.new do
+            def self.bar(machine)
+              raise "bar #{machine.id}"
+            end
+          end
+        end
+      end
+
+      machine.stub(id: "YEAH")
+
+      instance._initialize("foo", machine)
+    end
+
+    it "can execute capabilities" do
+      expect(subject.capability?(:foo)).to be_false
+      expect(subject.capability?(:bar)).to be_true
+
+      expect { subject.capability(:bar) }.
+        to raise_error("bar YEAH")
+    end
+  end
 end