Fixes #105: Add CLI hooks to mechanisms and plugins, implement --igno…

…re-app-stop-failures for CodeDeploy. (#184)

Fixes #105: Add CLI hooks to mechanisms and plugins.

docs/plugins.md

@@ -39,7 +39,40 @@ retreive the name of the stack, stack parameters and stack outputs. This support
 should be expanded in the future to provide Plugins with more control over the
 CloudFormation stack.
 
-## Adding a plugin to a CLI tool.
+## Manipulating CLI options with Plugins
+
+If you wish to modify the options accepted by a core Moonshot command
+in order to affect the pre/post hooks defined in your plugin,
+implement a method called `<action>_cli_hook`. This hook will be
+passed an instance of OptionParser, which you can manipulate and
+return. For example:
+
+```ruby
+class MyPlugin
+  def pre_build(_)
+    puts "FULL SPEED AHEAD!!!!" if @hyperdrive
+  end
+
+  def build_cli_hook(parser)
+    parser.on('--foo', '-F', TrueClass, 'ENABLE HYPERDRIVE') do |v|
+      @hyperdrive = v
+    end
+  end
+end
+```
+
+With this plugin, the output of `moonshot build --help` reflects the
+new command line option:
+
+```
+Usage: moonshot build VERSION
+    -v, --[no-]verbose               Show debug logging
+    -n, --environment=NAME           Which environment to operate on.
+        --[no-]interactive-logger    Enable or disable fancy logging
+    -F, --foo                        ENABLE HYPERDRIVE
+```
+
+## Adding a plugin to Moonshot
 
 Once you have defined or included your plugin class, you can add a
 plugin by modifying your `Moonfile.rb` file, like so:

lib/moonshot/command_line_dispatcher.rb

@@ -10,8 +10,11 @@ def dispatch!
       # Look to see if we're allowed only to run in certain accounts, or
       # not allowed to run in specific accounts.
       check_account_restrictions
+
+      # Allow any mechanisms or plugins to hook into this CLI command.
       handler = @klass.new
-      handler.parser.parse!
+      parser = build_parser(handler)
+      parser.parse!
 
       unless @args.size == handler.method(:execute).arity
         warn handler.parser.help
@@ -36,5 +39,33 @@ def check_account_restrictions
 
       raise 'Command account restriction violation.'
     end
+
+    def build_parser(handler)
+      parser = handler.parser
+
+      # Each mechanism / plugin may manipulate the OptionParser object
+      # associated with this command.
+      [:build_mechanism, :deployment_mechanism, :artifact_repository].each do |prov|
+        provider = Moonshot.config.send(prov)
+
+        if provider.respond_to?(hook_func_name(@command))
+          parser = provider.send(hook_func_name(@command), parser)
+        end
+      end
+
+      Moonshot.config.plugins.each do |plugin|
+        if plugin.respond_to?(hook_func_name(@command))
+          parser = plugin.send(hook_func_name(@command), parser)
+        end
+      end
+
+      parser
+    end
+
+    # Name of the function a plugin or mechanism could define to manipulate
+    # the parser for a command.
+    def hook_func_name(command)
+      command.tr('-', '_') << '_cli_hook'
+    end
   end
 end

lib/moonshot/deployment_mechanism/code_deploy.rb

@@ -40,6 +40,7 @@ def initialize(
     @group_name = group_name
     @codedeploy_role = role
     @codedeploy_config = config_name
+    @ignore_app_stop_failures = false
   end
 
   def post_create_hook
@@ -70,13 +71,7 @@ def deploy_hook(artifact_repo, version_name)
     deployment_id = nil
 
     ilog.start_threaded 'Creating Deployment' do |s|
-      res = cd_client.create_deployment(
-        application_name: app_name,
-        deployment_group_name: group_name,
-        revision: revision_for_artifact_repo(artifact_repo, version_name),
-        deployment_config_name: @codedeploy_config,
-        description: "Deploying version #{version_name}"
-      )
+      res = create_deployment(artifact_repo, version_name)
       deployment_id = res.deployment_id
       s.continue "Created Deployment #{deployment_id.blue}."
       success = wait_for_deployment(deployment_id, s)
@@ -96,6 +91,17 @@ def post_delete_hook
     end
   end
 
+  def deploy_cli_hook(parser)
+    parser.on('--ignore-app-stop-failures', TrueClass, 'Continue deployment on ApplicationStop failures') do |v| # rubocop:disable LineLength
+      puts "ignore = #{v}"
+      @ignore_app_stop_failures = v
+    end
+
+    parser
+  end
+
+  alias push_cli_hook deploy_cli_hook
+
   private
 
   # By default, use the stack name as the application name, unless one has been
@@ -333,6 +339,17 @@ def s3_revision_for(artifact_repo, version_name)
     }
   end
 
+  def create_deployment(artifact_repo, version_name)
+    cd_client.create_deployment(
+      application_name: app_name,
+      deployment_group_name: group_name,
+      revision: revision_for_artifact_repo(artifact_repo, version_name),
+      deployment_config_name: @codedeploy_config,
+      description: "Deploying version #{version_name}",
+      ignore_application_stop_failures: @ignore_app_stop_failures
+    )
+  end
+
   def doctor_check_code_deploy_role
     iam_client.get_role(role_name: @codedeploy_role).role
     success("#{@codedeploy_role} exists.")