providers/docker: remove built image on reload and destroy

plugins/providers/docker/action.rb

@@ -107,6 +107,7 @@ module VagrantPlugins
 
             b2.use ConfigValidate
             b2.use action_halt
+            b2.use DestroyBuildImage
             b2.use EnvSet, build_rebuild: true
             b2.use action_start
           end
@@ -135,6 +136,7 @@ module VagrantPlugins
                 b3.use EnvSet, :force_halt => true
                 b3.use action_halt
                 b3.use HostMachineSyncFoldersDisable
+                b3.use DestroyBuildImage
                 b3.use Destroy
                 b3.use ProvisionerCleanup
               else
@@ -250,6 +252,7 @@ module VagrantPlugins
       autoload :CompareSyncedFolders, action_root.join("compare_synced_folders")
       autoload :Create, action_root.join("create")
       autoload :Destroy, action_root.join("destroy")
+      autoload :DestroyBuildImage, action_root.join("destroy_build_image")
       autoload :HasSSH, action_root.join("has_ssh")
       autoload :HostMachine, action_root.join("host_machine")
       autoload :HostMachineBuildDir, action_root.join("host_machine_build_dir")

plugins/providers/docker/action/destroy_build_image.rb

@@ -0,0 +1,32 @@
+require "log4r"
+
+module VagrantPlugins
+  module DockerProvider
+    module Action
+      class DestroyBuildImage
+        def initialize(app, env)
+          @app = app
+          @logger = Log4r::Logger.new("vagrant::docker::destroybuildimage")
+        end
+
+        def call(env)
+          machine   = env[:machine]
+
+          # Try to read the image ID from the cache file if we've
+          # already built it.
+          image_file = machine.data_dir.join("docker_build_image")
+          image      = nil
+          if image_file.file?
+            image = image_file.read.chomp
+
+            machine.ui.output(I18n.t("docker_provider.build_image_destroy"))
+            machine.provider.driver.rmi(image)
+            image_file.delete
+          end
+
+          @app.call(env)
+        end
+      end
+    end
+  end
+end

plugins/providers/docker/driver.rb

@@ -94,6 +94,12 @@ module VagrantPlugins
         end
       end
 
+      def rmi(id)
+        execute('docker', 'rmi', id)
+      rescue Exception => e
+        raise if !e.to_s.include?("No such image")
+      end
+
       def inspect_container(cid)
         # DISCUSS: Is there a chance that this json will change after the container
         #          has been brought up?

templates/locales/providers_docker.yml

@@ -2,6 +2,8 @@ en:
   docker_provider:
     already_built: |-
       Image is already built from the Dockerfile. `vagrant reload` to rebuild.
+    build_image_destroy: |-
+      Removing built image...
     building: |-
       Building the container from a Dockerfile...
     creating: |-