GitLab Automated Merge Request Management Workflow

Workflow Name

GitLab Automated Merge Request Management Workflow

Key Features and Highlights

This workflow enables full-cycle automated management of merge requests (MRs) within GitLab projects, including detection, creation, updating, and closing. The system periodically checks for open merge requests on specified branches to prevent duplicate creation; automatically adds custom comments; intelligently merges after CI pipeline completion; and supports closing outdated merge requests. By automating these operations, it significantly reduces manual effort and the risk of errors in managing merge requests.

Core Problems Addressed

• Prevents duplicate merge requests for the same branch, ensuring uniqueness and validity of MRs
• Automatically adds remarks to improve communication efficiency around merge requests
• Automatically merges after pipeline success to maintain code quality
• Closes invalid or outdated merge requests to keep MR management clean
• Reduces manual operations to enhance team collaboration efficiency

Use Cases

• Software development teams requiring automated management of GitLab merge requests
• CI/CD pipelines that trigger automated merge request handling
• Multi-branch, multi-developer collaborative projects needing MR maintenance
• Automatically closing long-unprocessed or abandoned merge requests to maintain repository health

Main Workflow Steps

1. Scheduled Trigger: Periodically initiates the workflow to keep merge request statuses up to date.
2. Check Existing Merge Requests (via API): Uses GitLab API to verify if there are any open merge requests for the target branch.
3. Existence Check: Determines whether to create a new merge request based on the query results.
4. Create New Merge Request: Creates a new MR when no duplicates exist, specifying source branch, target branch, and title.
5. Add Custom Notes to Merge Request: Adds comments to the newly created MR for team awareness and context.
6. Wait for Pipeline Completion (30 seconds wait): Pauses to allow the CI pipeline to run and complete.
7. Set Merge Parameters: Configures options such as auto-merge upon pipeline success and whether to delete the source branch.
8. Auto Merge When Pipeline Succeeds: Automatically merges the MR once the pipeline passes successfully.
9. Batch Process Old Merge Requests: Iterates over all MRs to automatically close those that are no longer needed (via API).

Involved Systems and Services

• GitLab API: For querying, creating, updating, closing merge requests, and adding comments.
• n8n Automation Platform: Serves as the automation engine orchestrating and connecting all workflow nodes.

Target Users and Value

• Software Development Teams and DevOps Engineers: Saves significant time by automating repetitive MR management tasks.
• Project Managers and Team Leads: Enhances the standardization and visibility of code merge processes, reducing human errors.
• CI/CD Environments: Ensures code merges align with pipeline status, improving code quality and delivery efficiency.
• Projects with Multiple Branches and Collaborators: Effectively manages complex MR states to maintain a clean and orderly codebase.

This workflow is a powerful tool for automating GitLab merge request management, ideal for software teams aiming to improve code review and merge efficiency.