Prevent worker that updates merge requests head pipeline from failing jobsissue_41021

4 files changed, 26 insertions, 3 deletions

diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 422f138c4ea..c40e2a09012 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -83,6 +83,12 @@ class MergeRequest < ActiveRecord::Base
       transition locked: :opened
     end
 
+    before_transition any => :opened do |merge_request|
+      Sidekiq::Worker.skipping_transaction_check do
+        UpdateHeadPipelineForMergeRequestWorker.perform_async(merge_request.id)
+      end
+    end
+
     state :opened
     state :closed
     state :merged
diff --git a/app/services/ci/create_pipeline_service.rb b/app/services/ci/create_pipeline_service.rb
index 85db2760e23..c8b112132b3 100644
--- a/app/services/ci/create_pipeline_service.rb
+++ b/app/services/ci/create_pipeline_service.rb
@@ -81,7 +81,7 @@ module Ci
     end
 
     def related_merge_requests
-      MergeRequest.where(source_project: pipeline.project, source_branch: pipeline.ref)
+      MergeRequest.opened.where(source_project: pipeline.project, source_branch: pipeline.ref)
     end
   end
 end
diff --git a/app/workers/stuck_merge_jobs_worker.rb b/app/workers/stuck_merge_jobs_worker.rb
index 36d2a2e6466..e31fa0fea47 100644
--- a/app/workers/stuck_merge_jobs_worker.rb
+++ b/app/workers/stuck_merge_jobs_worker.rb
@@ -23,7 +23,13 @@ class StuckMergeJobsWorker
     merge_requests = MergeRequest.where(id: completed_ids)
 
     merge_requests.where.not(merge_commit_sha: nil).update_all(state: :merged)
-    merge_requests.where(merge_commit_sha: nil).update_all(state: :opened, merge_jid: nil)
+
+    merge_requests_to_reopen = merge_requests.where(merge_commit_sha: nil)
+    merge_requests_to_reopen.update_all(merge_jid: nil)
+
+    # Do not reopen merge requests using direct queries.
+    # We rely on state machine callbacks to update head_pipeline_id
+    merge_requests_to_reopen.map(&:unlock_mr)
 
     Rails.logger.info("Updated state of locked merge jobs. JIDs: #{completed_jids.join(', ')}")
   end
diff --git a/app/workers/update_head_pipeline_for_merge_request_worker.rb b/app/workers/update_head_pipeline_for_merge_request_worker.rb
index 0a2e9b63578..9614daf1976 100644
--- a/app/workers/update_head_pipeline_for_merge_request_worker.rb
+++ b/app/workers/update_head_pipeline_for_merge_request_worker.rb
@@ -8,8 +8,19 @@ class UpdateHeadPipelineForMergeRequestWorker
     pipeline = Ci::Pipeline.where(project: merge_request.source_project, ref: merge_request.source_branch).last
 
     return unless pipeline && pipeline.latest?
-    raise ArgumentError, 'merge request sha does not equal pipeline sha' if merge_request.diff_head_sha != pipeline.sha
+
+    if merge_request.diff_head_sha != pipeline.sha
+      log_error_message_for(merge_request)
+
+      return
+    end
 
     merge_request.update_attribute(:head_pipeline_id, pipeline.id)
   end
+
+  def log_error_message_for(merge_request)
+    Gitlab::EnvironmentLogger.error(
+      "Outdated head pipeline for active merge request: id=#{merge_request.id}, source_branch=#{merge_request.source_branch}, diff_head_sha=#{merge_request.diff_head_sha}"
+    )
+  end
 end