Refactor ApplyManifest to use separate strategies for command

[#154739913]

Signed-off-by: An Yu <anyu@pivotal.io>

app/actions/app_apply_manifest.rb

@@ -1,4 +1,5 @@
 require 'actions/process_scale'
+require 'cloud_controller/strategies/manifest_strategy'
 
 module VCAP::CloudController
   class AppApplyManifest
@@ -14,7 +15,7 @@ def apply(app_guid, message)
       lifecycle = AppLifecycleProvider.provide_for_update(app_update_message, app)
       AppUpdate.new(user_audit_info).update(app, app_update_message, lifecycle)
 
-      ProcessUpdate.new(user_audit_info).update(app.web_process, message.manifest_process_update_message)
+      ProcessUpdate.new(user_audit_info).update(app.web_process, message.manifest_process_update_message, ManifestStrategy)
 
       AppPatchEnvironmentVariables.new(user_audit_info).patch(app, message.manifest_env_update_message)
 

app/actions/current_process_types.rb

@@ -39,7 +39,7 @@ def evaluate_processes(app, process_types)
     def add_or_update_process(app, type, command)
       existing_process = app.processes_dataset.where(type: type).first
       if existing_process
-        ProcessUpdate.new(@user_audit_info).update(existing_process, ProcessUpdateMessage.new({ command: command }))
+        ProcessUpdate.new(@user_audit_info).update(existing_process, ProcessUpdateMessage.new({ command: command }), NonManifestStrategy)
       else
         ProcessCreate.new(@user_audit_info).create(app, { type: type, command: command })
       end

app/actions/process_update.rb

@@ -6,11 +6,12 @@ def initialize(user_audit_info)
       @user_audit_info = user_audit_info
     end
 
-    def update(process, message)
+    def update(process, message, strategy_class)
+      strategy = strategy_class.new(message, process)
       process.db.transaction do
         process.lock!
 
-        process.command              = message.command if message.requested?(:command)
+        process.command              = strategy.updated_command if message.requested?(:command)
         process.health_check_type    = message.health_check_type if message.requested?(:health_check_type)
         process.health_check_timeout = message.health_check_timeout if message.requested?(:health_check_timeout)
         if message.requested?(:health_check_type) && message.health_check_type != 'http'

app/controllers/v3/processes_controller.rb

@@ -12,6 +12,7 @@
 require 'messages/process_update_message'
 require 'messages/processes_list_message'
 require 'controllers/v3/mixins/app_sub_resource'
+require 'cloud_controller/strategies/non_manifest_strategy'
 
 class ProcessesController < ApplicationController
   include AppSubResource
@@ -45,7 +46,7 @@ def update
     message = ProcessUpdateMessage.create_from_http_request(unmunged_body)
     unprocessable!(message.errors.full_messages) unless message.valid?
 
-    ProcessUpdate.new(user_audit_info).update(@process, message)
+    ProcessUpdate.new(user_audit_info).update(@process, message, NonManifestStrategy)
 
     render status: :ok, json: Presenters::V3::ProcessPresenter.new(@process)
   rescue ProcessUpdate::InvalidProcess => e

app/models/helpers/process_types.rb

@@ -1,6 +1,5 @@
 module VCAP::CloudController
   class ProcessTypes
     WEB = 'web'.freeze
-    NULL_START_COMMANDS = ['default', 'null'].freeze
   end
 end

lib/cloud_controller/strategies/manifest_strategy.rb

@@ -0,0 +1,18 @@
+module VCAP::CloudController
+  class ManifestStrategy
+    NULL_START_COMMANDS = ['default', 'null'].freeze
+
+    def initialize(message, process)
+      @process = process
+      @message = message
+    end
+
+    def updated_command
+      if NULL_START_COMMANDS.include?(@message.command)
+        @process.detected_start_command
+      elsif @message.command
+        @message.command
+      end
+    end
+  end
+end

lib/cloud_controller/strategies/non_manifest_strategy.rb

@@ -0,0 +1,12 @@
+module VCAP::CloudController
+  class NonManifestStrategy
+    def initialize(message, process)
+      @process = process
+      @message = message
+    end
+
+    def updated_command
+      @message.command
+    end
+  end
+end

spec/unit/actions/app_apply_manifest_spec.rb

@@ -229,7 +229,7 @@ module VCAP::CloudController
             app_apply_manifest.apply(app.guid, message)
             expect(ProcessUpdate).to have_received(:new).with(user_audit_info)
             expect(process_update).to have_received(:update).
-              with(app.web_process, manifest_process_update_message)
+              with(app.web_process, manifest_process_update_message, ManifestStrategy)
           end
         end