Make pipeline processing asynchronous

app/models/ci/build.rb

@@ -67,7 +67,7 @@ module Ci
           environment: build.environment,
           status_event: 'enqueue'
         )
-        MergeRequests::AddTodoWhenBuildFailsService.new(build.project, nil).close(new_build)
+        MergeRequests::AddTodoWhenBuildFailsService.new(build.project, nil).close(new_build.pipeline)
         build.pipeline.mark_as_processable_after_stage(build.stage_idx)
         new_build
       end

app/models/ci/pipeline.rb

@@ -73,6 +73,14 @@ module Ci
       after_transition do |pipeline, transition|
         pipeline.execute_hooks unless transition.loopback?
       end
+
+      after_transition [:created, :pending, :running] => :success do |pipeline|
+        MergeRequests::MergeWhenBuildSucceedsService.new(pipeline.project, nil).trigger(pipeline)
+      end
+
+      after_transition any => :failed do |pipeline|
+        MergeRequests::AddTodoWhenBuildFailsService.new(pipeline.project, nil).execute(pipeline)
+      end
     end
 
     # ref can't be HEAD or SHA, can only be branch/tag name
@@ -251,9 +259,8 @@ module Ci
       Ci::ProcessPipelineService.new(project, user).execute(self)
     end
 
-    def build_updated
+    def update_status
       with_lock do
-        reload
         case latest_builds_status
         when 'pending' then enqueue
         when 'running' then run

app/models/commit_status.rb

@@ -74,10 +74,6 @@ class CommitStatus < ActiveRecord::Base
       true
     end
 
-    after_transition do |commit_status, transition|
-      commit_status.pipeline.try(:build_updated) unless transition.loopback?
-    end
-
     after_transition [:created, :pending, :running] => :success do |commit_status|
       MergeRequests::MergeWhenBuildSucceedsService.new(commit_status.pipeline.project, nil).trigger(commit_status)
     end
@@ -85,6 +81,16 @@ class CommitStatus < ActiveRecord::Base
     after_transition any => :failed do |commit_status|
       MergeRequests::AddTodoWhenBuildFailsService.new(commit_status.pipeline.project, nil).execute(commit_status)
     end
+
+    after_transition do |commit_status, transition|
+      if commit_status.pipeline && !transition.loopback?
+        ProcessPipelineWorker.perform_async(
+          commit_status.pipeline.id,
+          process: HasStatus.COMPLETED_STATUSES.include?(commit_status.status))
+      end
+
+      true
+    end
   end
 
   delegate :sha, :short_sha, to: :pipeline

app/services/merge_requests/add_todo_when_build_fails_service.rb

 module MergeRequests
   class AddTodoWhenBuildFailsService < MergeRequests::BaseService
     # Adds a todo to the parent merge_request when a CI build fails
-    def execute(commit_status)
-      each_merge_request(commit_status) do |merge_request|
+    def execute(pipeline)
+      each_merge_request(pipeline) do |merge_request|
         todo_service.merge_request_build_failed(merge_request)
       end
     end
 
     # Closes any pending build failed todos for the parent MRs when a build is retried
-    def close(commit_status)
-      each_merge_request(commit_status) do |merge_request|
+    def close(pipeline)
+      each_merge_request(pipeline) do |merge_request|
         todo_service.merge_request_build_retried(merge_request)
       end
     end

app/services/merge_requests/base_service.rb

@@ -42,11 +42,11 @@ module MergeRequests
       super(:merge_request)
     end
 
-    def merge_request_from(commit_status)
-      branches = commit_status.ref
+    def merge_request_from(pipeline)
+      branches = pipeline.ref
 
       # This is for ref-less builds
-      branches ||= @project.repository.branch_names_contains(commit_status.sha)
+      branches ||= @project.repository.branch_names_contains(pipeline.sha)
 
       return [] if branches.blank?
 
@@ -56,14 +56,11 @@ module MergeRequests
       merge_requests.uniq.select(&:source_project)
     end
 
-    def each_merge_request(commit_status)
+    def each_merge_request(pipeline)
       merge_request_from(commit_status).each do |merge_request|
-        pipeline = merge_request.pipeline
+        next unless pipeline == merge_request.pipeline
 
-        next unless pipeline
-        next unless pipeline.sha == commit_status.sha
-
-        yield merge_request, pipeline
+        yield merge_request
       end
     end
   end

app/services/merge_requests/merge_when_build_succeeds_service.rb

@@ -19,11 +19,12 @@ module MergeRequests
     end
 
     # Triggers the automatic merge of merge_request once the build succeeds
-    def trigger(commit_status)
-      each_merge_request(commit_status) do |merge_request, pipeline|
+    def trigger(pipeline)
+      return unless pipeline.success?
+
+      each_merge_request(pipeline) do |merge_request|
         next unless merge_request.merge_when_build_succeeds?
         next unless merge_request.mergeable?
-        next unless pipeline.success?
 
         MergeWorker.perform_async(merge_request.id, merge_request.merge_user_id, merge_request.merge_params)
       end

app/workers/process_pipeline_worker.rb

+class ProcessPipelineWorker
+  include Sidekiq::Worker
+
+  sidekiq_options queue: :default
+
+  def perform(pipeline_id, params)
+    begin
+      pipeline = Ci::Pipeline.find(pipeline_id)
+    rescue ActiveRecord::RecordNotFound
+      return
+    end
+
+    pipeline.process! if params[:process]
+
+    pipeline.update_status
+  end
+end