Automate GitLab Merge Requests Using APIs with n8n

Who is this template for?

This template is designed for developers, DevOps engineers, and automation enthusiasts who want to streamline their GitLab merge request process using n8n, a low-code workflow automation tool. It eliminates manual intervention by automating the merging of GitLab branches through API calls.

How it works ?

Trigger the workflow: The workflow can be triggered by a webhook, a scheduled event, or a GitLab event (e.g., a new merge request is created or approved).

Fetch Merge Request Details: n8n makes an API call to GitLab to retrieve merge request details.

Check Merge Conditions: The workflow validates whether the merge request meets predefined conditions (e.g., approvals met, CI/CD pipelines passed).

Perform the Merge: If all conditions are met, n8n sends a request to the GitLab API to merge the branch automatically.

Setup Steps

1. Prerequisites

An n8n instance (Self-hosted or Cloud)

A GitLab personal access token with API access

A GitLab repository with merge requests enabled

2. Create the n8n Workflow

Set up a trigger: Choose a trigger node (Webhook, Cron, or GitLab Trigger).

Fetch merge request details: Add an HTTP Request node to call GET /merge_requests/:id from GitLab API.

Validate conditions:

Check if the merge request has necessary approvals.

Ensure CI/CD pipelines have passed.

Merge the request:

Use an HTTP Request node to call PUT /merge_requests/:id/merge API.

3. Test the Workflow

Create a test merge request.

Check if the workflow triggers and merges automatically.

Debug using n8n logs if needed.

4. Deploy and Monitor

Deploy the workflow in production.

Use n8n’s monitoring features to track execution.

This template enables seamless GitLab merge automation, improving efficiency and reducing manual work!

Note: Never hard code API token or secret in your https request.