How to trigger CI/CD pipeline only on master branch using GitLab CI/CD configuration?

Question

I have a GitLab CI/CD configuration where I want the pipeline to be triggered only when changes are pushed to the master branch. Below is a simplified version of my .gitlab-ci.yml file:

stages:
    - deploy

deploy:
    stage: deploy
    rules:
        - if: '$CI_COMMIT_REF_NAME == "master"'
        - when: manual
    before_script:
        - apt-get update && apt-get install sshpass && apt-get install make
        - chmod 400 $SSH_KEY
    script:
        - sshpass -p $SSH_PASS ssh -o "StrictHostKeyChecking=no" $USER_NAME@$HOST "cd /home/backend && git pull && make docker-restart"

With this configuration, the pipeline should only run when changes are pushed to the master branch. However, it seems like the pipeline is triggered even when changes are pushed to other branches.

How can I modify my GitLab CI/CD configuration to ensure that the pipeline is triggered only when changes are pushed to the master branch?

Answer 1

There's a small typo in your if key, but besides that I think you'd be better using the variable $CI_COMMIT_BRANCH instead, as the one you're currently using takes into account tags too. Also as a small improvement, if your default branch is master you can do the check with a variable too:

stages:
    - deploy

deploy:
    stage: deploy
    rules:
        - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH
          when: manual
    before_script:
        - apt-get update && apt-get install sshpass && apt-get install make
        - chmod 400 $SSH_KEY
    script:
        - sshpass -p $SSH_PASS ssh -o "StrictHostKeyChecking=no" $USER_NAME@$HOST "cd /home/backend && git pull && make docker-restart"

Full reference for GitLab's predefined variables can be found here.