GitLab CI and CD - rishavry/WorksPresentation GitHub Wiki

  • CI/CD is a continuous method of software development, where you continuously build, test, deploy, and monitor iterative code changes. GitLab is a popular tool for this.

  • In my Megagram project, I would use GitLab for the smooth deployment of all my frontends and backends; specifically, all my frontends and backends will have to pass tests, and if they do, then the production-code gets updated in a timely fashion.

  • Here is what I would do to use GitLab for CI/CD- I would add a file called .gitlab-ci.yml(which will be executed by the 'GitLab runner' anytime a git commit occurs in the remote-repo) with content similar to the following-

    variables:
    IMAGE_NAME: docker-username/docker-registry #this will be the name of the image you would 
    IMAGE_TAG: insert-image-tag-here


stages: #the stages will be executed in order from top to bottom, and if any stage fails, the remaining stages
    # will not take place; furthermore, the git push will fail if any stage fails, and all jobs that are
    # in the same stage will be executed concurrently
    - test  #testing code of current-state of repository (CI)
    - build #building docker-image of current-state of repository
    - deploy #deploying docker-image of current-state of repository (CD)


run_tests:  #job 1, which will be taking place in a Docker container
    image: insert-image-here:insert-tag-here 
    before_script:
        - apt-get update && apt-get install make
    script:
        - make test


build_image: #job 2, which will be taking place in another Docker container
    stage: build
    image: docker:28.2.2
    services:
        - docker:28.2.2-dind
    variables:
        DOCKER_TLS_CERTDIR = "/certs"
    before_script:
        - docker login -u $REGISTRY_USER -p $REGISTRY_PASS #$REGISTRY_USER and $REGISTRY_PASS are secure secret variables whose values were declared in the GitLab website
    script:
        - docker build -t $IMAGE_NAME:$IMAGE_TAG . #the repository 
        - docker push $IMAGE_NAME:$IMAGE_TAG   


deploy_image: #job 3, which will be taking place in another Docker container
    stage: deploy
    script:
        - #ssh into the master-node of the Kubernetes-cluster, delete the current deployment of the docker-image that represented the state of the 
        # repository in the previous commit. then deploy the newly-pushed docker-image that reflects the current state of the repository
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