CE port for pipelines for external pull requestsce-detect-github-pull-requests

Detect if pipeline runs for a GitHub pull request

When using a mirror for CI/CD only we register a pull_request
webhook. When a pull_request webhook is received, if the
source branch SHA matches the actual head of the branch in the
repository we create immediately a new pipeline for the
external pull request. Otherwise we store the
pull request info for when the push webhook is received.

When using "only/except: external_pull_requests" we can detect
if the pipeline has a open pull request on GitHub and create or
not the job based on that.

1 files changed, 25 insertions, 0 deletions

diff --git a/app/workers/update_external_pull_requests_worker.rb b/app/workers/update_external_pull_requests_worker.rb
new file mode 100644
index 00000000000..c5acfa82ada
--- /dev/null
+++ b/app/workers/update_external_pull_requests_worker.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+class UpdateExternalPullRequestsWorker
+  include ApplicationWorker
+
+  def perform(project_id, user_id, ref)
+    project = Project.find_by_id(project_id)
+    return unless project
+
+    user = User.find_by_id(user_id)
+    return unless user
+
+    branch = Gitlab::Git.branch_name(ref)
+    return unless branch
+
+    external_pull_requests = project.external_pull_requests
+      .by_source_repository(project.import_source)
+      .by_source_branch(branch)
+
+    external_pull_requests.find_each do |pull_request|
+      ExternalPullRequests::CreatePipelineService.new(project, user)
+        .execute(pull_request)
+    end
+  end
+end