GitLab Bot

This is a GitLab bot, which at the moment only promotes changes from a source branch to a target branch by creating a merge request whenever the contents of the two branches differ. It supports GitLab webhooks to automatically check for changes on the project whenever GitLab receives a push.

Features

• Support for GitLab webhooks to automatically check for changes on push
• Automatically create merge requests if branch contents differ
• Project-specific configuration via a gitlab-bot.yml file
• Attach specified labels to automatically created merge requests

Project Configuration

Note: Unless already done, please install the bot server before configuring a project.

1. Create a gitlab-bot.yml in the default branch of the project you want to enable GitLab Bot for. This is an example:

   promote_branches:
   - source: exp
     target: sandbox
     labels:
       - Automated
   - source: sandbox
     target: production
     labels:
       - Automated
   

   • source and target refer to the source and target branch
   • labels refers to GitLab labels attached to the create merger requests.

2. Set up a GitLab webhook integration for the project.

   • URL: https://<gitlab-bot-host>/webhook
   • Secret Token: As configured for the bot
   • Trigger: Only 'Push Events'
   • Enable SSL verification: Yes

3. Add the GitLab bot user to the project.

   • Role: Developer

Installation

GitLab User

Create a GitLab user with the following settings:

• Access Level: Regular
• External: Yes (no need to give this user more access than necessary)
• URL: Add a link to this project repository to allow users to understand the bot (optional).

Log in as this user (unless you can't due to SSO), otherwise you must be a GitLab admin and impersonate it.

Go to the user's Settings, Access Tokens and create a new personal access token with the following setting:

• Scopes: api

You might also want to disable all email notifications for the user under Settings, Notifications.

Bot Server

For a server deploment, GitLab bot needs the following environment variables set:

• APP_URL - The GitLab instance URL
• APP_PRIVATE_TOKEN - A private token to authenticate against GitLab as GitLab user.
• APP_SERVER_WEBHOOK_AUTH_TOKEN - A random value that needs to be shared with GitLab, for authentication (generate e.g. using openssl rand -hex 20). The value set here must be put into the Secret Token field in GitLab, as shown above.

Deployment

Deployment happens automatically via GitLab CI on Kubernetes (via kustomize). See .gitlab-ci.yml and kubernetes/ for details.

For recreating the secret containing the environment variables above, you can use the following command:

kubectl create secret generic gitlab-bot \
    --from-literal=APP_URL=https://gitlab.example.com \
    --from-literal=APP_SERVER_WEBHOOK_AUTH_TOKEN='randomly-generated-string' \
    --from-literal=APP_PRIVATE_TOKEN=='token-from-gitlab'