Add optional support for docker-compose

Adds configuration switch to enable using docker-compose
to create and manage docker containers.

plugins/providers/docker/config.rb

@@ -19,6 +19,8 @@ module VagrantPlugins
       # @return [String]
       attr_accessor :build_dir
 
+      attr_accessor :compose
+
       # An optional file name of a Dockerfile to be used when building
       # the image. This requires Docker >1.5.0.
       #
@@ -138,6 +140,7 @@ module VagrantPlugins
         @build_args = []
         @build_dir  = UNSET_VALUE
         @cmd        = UNSET_VALUE
+        @compose    = UNSET_VALUE
         @create_args = UNSET_VALUE
         @dockerfile = UNSET_VALUE
         @env        = {}
@@ -201,6 +204,7 @@ module VagrantPlugins
         @build_args = [] if @build_args == UNSET_VALUE
         @build_dir  = nil if @build_dir == UNSET_VALUE
         @cmd        = [] if @cmd == UNSET_VALUE
+        @compose    = false if @compose == UNSET_VALUE
         @create_args = [] if @create_args == UNSET_VALUE
         @dockerfile = nil if @dockerfile == UNSET_VALUE
         @env       ||= {}

plugins/providers/docker/driver.rb

@@ -1,7 +1,8 @@
 require "json"
-
 require "log4r"
 
+require_relative "./driver/compose"
+
 module VagrantPlugins
   module DockerProvider
     class Driver

plugins/providers/docker/driver/compose.rb

@@ -0,0 +1,166 @@
+require "json"
+require "log4r"
+
+module VagrantPlugins
+  module DockerProvider
+    class Driver
+      class Compose < Driver
+
+        # @return [String] Compose file format version
+        COMPOSE_VERSION = "2".freeze
+
+        # @return [Pathname] data directory to store composition
+        attr_reader :data_directory
+        # @return [Vagrant::Machine]
+        attr_reader :machine
+
+        # Create a new driver instance
+        #
+        # @param [Vagrant::Machine] machine Machine instance for this driver
+        def initialize(machine)
+          super()
+          @machine = machine
+          @data_directory = Pathname.new(machine.env.local_data_path).
+            join("docker-compose")
+          @data_directory.mkpath
+          @logger = Log4r::Logger.new("vagrant::docker::driver::compose")
+          @compose_lock = Mutex.new
+        end
+
+        def build(dir, **opts, &block)
+          update_composition do |composition|
+            composition["build"] = dir
+          end
+        end
+
+        def create(params, **opts, &block)
+          # NOTE: Use the direct machine name as we don't
+          # need to worry about uniqueness with compose
+          name    = machine.name.to_s
+          image   = params.fetch(:image)
+          links   = params.fetch(:links)
+          ports   = Array(params[:ports])
+          volumes = Array(params[:volumes])
+          cmd     = Array(params.fetch(:cmd))
+          env     = params.fetch(:env)
+          expose  = Array(params[:expose])
+
+          begin
+            update_composition do |composition|
+              services = composition["services"] ||= {}
+              services[name] = {
+                "image" => image,
+                "environment" => env,
+                "expose" => expose,
+                "ports" => ports,
+                "volumes" => volumes,
+                "links" => links,
+                "command" => cmd
+              }
+            end
+          rescue
+            update_composition(false) do |composition|
+              composition["services"].delete(name)
+            end
+            raise
+          end
+          get_container_id(name)
+        end
+
+        def rm(cid)
+          if created?(cid)
+            destroy = false
+            compose_execute("rm", "-f", machine.name.to_s)
+            update_composition do |composition|
+              if composition["services"] && composition["services"].key?(machine.name.to_s)
+                @logger.info("Removing container `#{machine.name}`")
+                composition["services"].delete(machine.name.to_s)
+                destroy = composition["services"].empty?
+              end
+            end
+            if destroy
+              @logger.info("No containers remain. Destroying full environment.")
+              compose_execute("down", "--remove-orphans")
+            end
+          end
+        end
+
+        def created?(cid)
+          result = super
+          if !result
+            composition = get_current_composition
+            if composition["services"] && composition["services"].has_key?(machine.name.to_s)
+              result = true
+            end
+          end
+          result
+        end
+
+        private
+
+        # Lookup the ID for the container with the given name
+        #
+        # @param [String] name Name of container
+        # @return [String] Container ID
+        def get_container_id(name)
+          compose_execute("ps", "-q", name).chomp
+        end
+
+        # Execute a `docker-compose` command
+        def compose_execute(*cmd, **opts)
+          @compose_lock.synchronize do
+            execute("docker-compose", "-f", composition_path.to_s,
+              "-p", machine.env.cwd.basename.to_s, *cmd, **opts)
+          end
+        end
+
+        # Apply any changes made to the composition
+        def apply_composition!
+          machine.env.lock("compose", retry: true) do
+            compose_execute("up", "-d", "--remove-orphans")
+          end
+        end
+
+        # Update the composition and apply changes if requested
+        #
+        # @param [Boolean] apply Apply composition changes
+        def update_composition(apply=true)
+          machine.env.lock("compose", retry: true) do
+            composition = get_current_composition
+            yield composition
+            write_composition(composition)
+            apply_composition! if apply
+          end
+        end
+
+        # @return [Hash] current composition contents
+        def get_current_composition
+          composition = {"version" => COMPOSE_VERSION.dup}
+          if composition_path.exist?
+            composition.merge!(
+              YAML.load(composition_path.read)
+            )
+          end
+          composition
+        end
+
+        # Save the composition
+        #
+        # @param [Hash] composition New composition
+        def write_composition(composition)
+          tmp_file = Tempfile.new("vagrant-docker-compose")
+          tmp_file.write(composition.to_yaml)
+          tmp_file.close
+          @compose_lock.synchronize do
+            FileUtils.mv(tmp_file.path, composition_path.to_s)
+          end
+        end
+
+        # @return [Pathname] path to the docker-compose.yml file
+        def composition_path
+          data_directory.join("docker-compose.yml")
+        end
+      end
+    end
+  end
+end

plugins/providers/docker/provider.rb

@@ -31,11 +31,13 @@ module VagrantPlugins
 
       # Returns the driver instance for this provider.
       def driver
-        return @driver if @driver
+        if !@driver
+          if @machine.provider_config.compose
+            @driver = Driver::Compose.new(@machine)
+          else
             @driver = Driver.new
-
-        # If we are running on a host machine, then we set the executor
-        # to execute remotely.
+          end
+        end
         if host_vm?
           @driver.executor = Executor::Vagrant.new(host_vm)
         end