synced_folders/nfs: automatically install NFS client if possible

If guests have the following capabilities, automatic NFS client
installation will be done:

  * nfs_client_installed - Checks if the NFS client is installed
  * nfs_client_install - Install the NFS client

Support is already in for Debian, Ubuntu, RedHat, CentOS, and Fedora

CHANGELOG.md

@@ -36,6 +36,8 @@ IMPROVEMENTS:
     plugins.
   - commands/plugin: `vagrant plugin install` can now install multiple
     plugins.
+  - synced\_folders/nfs: If the guest supports it, NFS clients will be
+    automatically installed in the guest.
 
 BUG FIXES:
 

lib/vagrant/errors.rb

@@ -360,6 +360,10 @@ module Vagrant
       error_key(:nfs_no_valid_ids)
     end
 
+    class NFSClientNotInstalledInGuest < VagrantError
+      error_key(:nfs_client_not_installed_in_guest)
+    end
+
     class NoDefaultSyncedFolderImpl < VagrantError
       error_key(:no_default_synced_folder_impl)
     end

plugins/guests/debian/cap/nfs_client.rb

@@ -0,0 +1,14 @@
+module VagrantPlugins
+  module GuestDebian
+    module Cap
+      class NFSClient
+        def self.nfs_client_install(machine)
+          machine.communicate.tap do |comm|
+            comm.sudo("apt-get -y update")
+            comm.sudo("apt-get -y install nfs-common portmap")
+          end
+        end
+      end
+    end
+  end
+end

plugins/guests/debian/plugin.rb

@@ -20,6 +20,11 @@ module VagrantPlugins
         require_relative "cap/change_host_name"
         Cap::ChangeHostName
       end
+
+      guest_capability("linux", "nfs_client_install") do
+        require_relative "cap/nfs_client"
+        Cap::NFSClient
+      end
     end
   end
 end

plugins/guests/linux/cap/nfs_client.rb

@@ -0,0 +1,11 @@
+module VagrantPlugins
+  module GuestLinux
+    module Cap
+      class NFSClient
+        def self.nfs_client_installed(machine)
+          machine.communicate.test("test -x /sbin/mount.nfs")
+        end
+      end
+    end
+  end
+end

plugins/guests/linux/plugin.rb

@@ -36,6 +36,11 @@ module VagrantPlugins
         Cap::MountVirtualBoxSharedFolder
       end
 
+      guest_capability("linux", "nfs_client_installed") do
+        require_relative "cap/nfs_client"
+        Cap::NFSClient
+      end
+
       guest_capability("linux", "read_ip_address") do
         require_relative "cap/read_ip_address"
         Cap::ReadIPAddress

plugins/guests/redhat/cap/nfs_client.rb

@@ -0,0 +1,13 @@
+module VagrantPlugins
+  module GuestRedHat
+    module Cap
+      class NFSClient
+        def self.nfs_client_install(machine)
+          machine.communicate.tap do |comm|
+            comm.sudo("yum -y install nfs-utils nfs-utils-lib")
+          end
+        end
+      end
+    end
+  end
+end

plugins/guests/redhat/plugin.rb

@@ -25,6 +25,11 @@ module VagrantPlugins
         require_relative "cap/network_scripts_dir"
         Cap::NetworkScriptsDir
       end
+
+      guest_capability("linux", "nfs_client_install") do
+        require_relative "cap/nfs_client"
+        Cap::NFSClient
+      end
     end
   end
 end

plugins/synced_folders/nfs/synced_folder.rb

@@ -37,6 +37,16 @@ module VagrantPlugins
         raise Vagrant::Errors::NFSNoHostIP if !nfsopts[:nfs_host_ip]
         raise Vagrant::Errors::NFSNoGuestIP if !nfsopts[:nfs_machine_ip]
 
+        if machine.guest.capability?(:nfs_client_installed)
+          installed = machine.guest.capability(:nfs_client_installed)
+          if !installed
+            can_install = machine.guest.capability?(:nfs_client_install)
+            raise Vagrant::Errors::NFSClientNotInstalledInGuest if !can_install
+            machine.ui.info I18n.t("vagrant.actions.vm.nfs.installing")
+            machine.guest.capability(:nfs_client_install)
+          end
+        end
+
         machine_ip = nfsopts[:nfs_machine_ip]
         machine_ip = [machine_ip] if !machine_ip.is_a?(Array)
 

templates/locales/en.yml

@@ -469,6 +469,14 @@ en:
         No valid IDs were given to the NFS synced folder implementation to
         prune. This is an internal bug with Vagrant and an issue should be
         filed.
+      nfs_client_not_installed_in_guest: |-
+        No NFS client was detected as installed in your guest machine. This
+        is required for NFS synced folders to work. In addition to this, Vagrant
+        doesn't know how to automatically install NFS for your machine, so
+        you must do this manually.
+
+        If this message is erroneous, you may disable this check by setting
+        `config.nfs.verify_installed` to `false` in your Vagrantfile.
       no_default_synced_folder_impl: |-
         No synced folder implementation is available for your synced folders!
         Please consult the documentation to learn why this may be the case.
@@ -1116,6 +1124,7 @@ en:
           preparing: "Preparing host only network..."
         nfs:
           exporting: Exporting NFS shared folders...
+          installing: "Installing NFS client..."
           mounting: Mounting NFS shared folders...
         provision:
           beginning: "Running provisioner: %{provisioner}..."