Start creating the plugin middleware sequences

lib/vagrant/environment.rb

@@ -411,6 +411,7 @@ module Vagrant
           :box_collection => boxes,
           :global_config  => config_global,
           :host           => host,
+          :gems_path      => gems_path,
           :root_path      => root_path,
           :tmp_path       => tmp_path,
           :ui             => @ui

plugins/commands/gem/command.rb

@@ -15,7 +15,7 @@ module VagrantPlugins
         if defined?(Bundler)
           require 'bundler/shared_helpers'
           if Bundler::SharedHelpers.in_bundle?
-            raise Errors::GemCommandInBundler
+            raise Vagrant::Errors::GemCommandInBundler
           end
         end
 

plugins/commands/plugin/action.rb

@@ -0,0 +1,22 @@
+require "pathname"
+
+require "vagrant/action/builder"
+
+module VagrantPlugins
+  module CommandPlugin
+    module Action
+      # This middleware sequence will install a plugin.
+      def self.action_install
+        Vagrant::Action::Builder.new.tap do |b|
+          b.use BundlerCheck
+          b.use InstallGem
+        end
+      end
+
+      # The autoload farm
+      action_root = Pathname.new(File.expand_path("../action", __FILE__))
+      autoload :BundlerCheck, action_root.join("bundler_check")
+      autoload :InstallGem, action_root.join("install_gem")
+    end
+  end
+end

plugins/commands/plugin/action/bundler_check.rb

@@ -0,0 +1,25 @@
+module VagrantPlugins
+  module CommandPlugin
+    module Action
+      class BundlerCheck
+        def initialize(app, env)
+          @app = app
+        end
+
+        def call(env)
+          # Bundler sets up its own custom gem load paths such that our
+          # own gems are never loaded. Therefore, give an error if a user
+          # tries to install gems while within a Bundler-managed environment.
+          if defined?(Bundler)
+            require 'bundler/shared_helpers'
+            if Bundler::SharedHelpers.in_bundle?
+              raise Vagrant::Errors::GemCommandInBundler
+            end
+          end
+
+          @app.call(env)
+        end
+      end
+    end
+  end
+end

plugins/commands/plugin/action/install_gem.rb

@@ -0,0 +1,47 @@
+require "rubygems"
+require "rubygems/gem_runner"
+
+require "log4r"
+
+module VagrantPlugins
+  module CommandPlugin
+    module Action
+      # This action takes the `:plugin_name` variable in the environment
+      # and installs it using the RubyGems API.
+      class InstallGem
+        def initialize(app, env)
+          @app    = app
+          @logger = Log4r::Logger.new("vagrant::plugins::plugincommand::installgem")
+        end
+
+        def call(env)
+          plugin_name = env[:plugin_name]
+
+          # First, install the gem
+          begin
+            # Set the GEM_HOME so that it is installed into our local gems path
+            old_gem_home = ENV["GEM_HOME"]
+            ENV["GEM_HOME"] = env[:gems_path].to_s
+            p ENV["GEM_PATH"]
+            @logger.debug("Set GEM_HOME to: #{ENV["GEM_HOME"]}")
+
+            @logger.info("Installing gem: #{plugin_name}")
+            env[:ui].info(
+              I18n.t("vagrant.commands.plugin.installing", :name => plugin_name))
+            Gem.clear_paths
+            Gem::GemRunner.new.run(
+              ["install", plugin_name, "--no-ri", "--no-rdoc"])
+          ensure
+            ENV["GEM_HOME"] = old_gem_home
+          end
+
+          # Mark that we installed the gem
+          env[:plugin_state_file].add_plugin(plugin_name)
+
+          # Continue
+          @app.call(env)
+        end
+      end
+    end
+  end
+end

plugins/commands/plugin/command/install.rb

@@ -0,0 +1,29 @@
+require 'optparse'
+
+module VagrantPlugins
+  module CommandPlugin
+    module Command
+      class Install < Vagrant.plugin("2", :command)
+        def execute
+          opts = OptionParser.new do |o|
+            o.banner = "Usage: vagrant plugin install <name> [-h]"
+          end
+
+          # Parse the options
+          argv = parse_options(opts)
+          return if !argv
+          raise Vagrant::Errors::CLIInvalidUsage, :help => opts.help.chomp if argv.length < 1
+
+          # Install the gem
+          @env.action_runner.run(Action.action_install, {
+            :plugin_name => argv[0],
+            :plugin_state_file => StateFile.new(@env.data_dir.join("plugins.json"))
+          })
+
+          # Success, exit status 0
+          0
+        end
+      end
+    end
+  end
+end

plugins/commands/plugin/command/root.rb

@@ -10,6 +10,10 @@ module VagrantPlugins
           @main_args, @sub_command, @sub_args = split_main_and_subcommand(argv)
 
           @subcommands = Vagrant::Registry.new
+          @subcommands.register(:install) do
+            require_relative "install"
+            Install
+          end
         end
 
         def execute

plugins/commands/plugin/plugin.rb

@@ -14,5 +14,8 @@ DESC
         Command::Root
       end
     end
+
+    autoload :Action, File.expand_path("../action", __FILE__)
+    autoload :StateFile, File.expand_path("../state_file", __FILE__)
   end
 end

plugins/commands/plugin/state_file.rb

@@ -0,0 +1,32 @@
+require "json"
+
+module VagrantPlugins
+  module CommandPlugin
+    # This is a helper to deal with the plugin state file that Vagrant
+    # uses to track what plugins are installed and activated and such.
+    class StateFile
+      def initialize(path)
+        @path = path
+
+        @data = {}
+        @data = JSON.parse(@path.read) if @path.exist?
+      end
+
+      # Add a plugin that is installed to the state file.
+      #
+      # @param [String] name The name of the plugin
+      def add_plugin(name)
+        @data["installed"] ||= []
+        @data["installed"] << name
+        save!
+      end
+
+      # This saves the state back into the state file.
+      def save!
+        @path.open("w+") do |f|
+          f.write(JSON.dump(@data))
+        end
+      end
+    end
+  end
+end

templates/locales/en.yml

@@ -411,6 +411,9 @@ en:
           ready to `vagrant up` your first virtual environment! Please read
           the comments in the Vagrantfile as well as documentation on
           `vagrantup.com` for more information on using Vagrant.
+      plugin:
+        installing: |-
+          Installing the '%{name}' plugin...
       status:
         aborted: |-
           The VM is in an aborted state. This means that it was abruptly