Merge branch 'trigger-downstream-pipelines-against-stable-branch-automatically' into 'master'

Automatically trigger downstream pipelines against stable branches

See merge request gitlab-org/gitlab!83602

scripts/trigger-build.rb

@@ -83,7 +83,7 @@ def simple_forwarded_variables
     # Override to trigger and work with pipeline on different GitLab instance
     # type: :downstream -> downstream build and pipeline status
     # type: :upstream -> this project, e.g. for posting comments
-    def gitlab_client(type)
+    def gitlab_client(_type)
       # By default, always use the same client
       @gitlab_client ||= Gitlab.client(
         endpoint: 'https://gitlab.com/api/v4',
@@ -97,10 +97,15 @@ def downstream_project_path
     end
 
     # Must be overridden
-    def ref
+    def ref_param_name
       raise NotImplementedError
     end
 
+    # Can be overridden
+    def primary_ref
+      'main'
+    end
+
     # Can be overridden
     def trigger_token
       ENV['CI_JOB_TOKEN']
@@ -116,6 +121,27 @@ def version_param_value(version_file)
       ENV[version_file]&.strip || File.read(version_file).strip
     end
 
+    # Can be overridden
+    def trigger_stable_branch_if_detected?
+      false
+    end
+
+    def stable_branch?
+      ENV['CI_COMMIT_REF_NAME'] =~ /^[\d-]+-stable(-ee)?$/
+    end
+
+    def fallback_ref
+      if trigger_stable_branch_if_detected? && stable_branch?
+        ENV['CI_COMMIT_REF_NAME'].delete_suffix('-ee')
+      else
+        primary_ref
+      end
+    end
+
+    def ref
+      ENV.fetch(ref_param_name, fallback_ref)
+    end
+
     def base_variables
       # Use CI_MERGE_REQUEST_SOURCE_BRANCH_SHA for omnibus checkouts due to pipeline for merged results,
       # and fallback to CI_COMMIT_SHA for the `detached` pipelines.
@@ -146,8 +172,16 @@ def downstream_project_path
       ENV.fetch('OMNIBUS_PROJECT_PATH', 'gitlab-org/build/omnibus-gitlab-mirror')
     end
 
-    def ref
-      ENV.fetch('OMNIBUS_BRANCH', 'master')
+    def ref_param_name
+      'OMNIBUS_BRANCH'
+    end
+
+    def primary_ref
+      'master'
+    end
+
+    def trigger_stable_branch_if_detected?
+      true
     end
 
     def extra_variables
@@ -184,10 +218,16 @@ def variables
 
     private
 
-    def ref
-      return ENV['CI_COMMIT_REF_NAME'] if ENV['CI_COMMIT_REF_NAME'] =~ /^[\d-]+-stable(-ee)?$/
+    def ref_param_name
+      'CNG_BRANCH'
+    end
+
+    def primary_ref
+      'master'
+    end
 
-      ENV.fetch('CNG_BRANCH', 'master')
+    def trigger_stable_branch_if_detected?
+      true
     end
 
     def extra_variables
@@ -272,8 +312,8 @@ def downstream_project_path
       ENV.fetch('DOCS_PROJECT_PATH', 'gitlab-org/gitlab-docs')
     end
 
-    def ref
-      ENV.fetch('DOCS_BRANCH', 'main')
+    def ref_param_name
+      'DOCS_BRANCH'
     end
 
     # `gitlab-org/gitlab-docs` pipeline trigger "Triggered from gitlab-org/gitlab 'review-docs-deploy' job"
@@ -377,8 +417,12 @@ def extra_variables
       }
     end
 
-    def ref
-      ENV['GITLABCOM_DATABASE_TESTING_TRIGGER_REF'] || 'master'
+    def ref_param_name
+      'GITLABCOM_DATABASE_TESTING_TRIGGER_REF'
+    end
+
+    def primary_ref
+      'master'
     end
   end