GitLab CI and Other Platforms

While GitHub Actions is popular, it is not the only CI/CD platform. This lesson covers GitLab CI/CD, Jenkins, CircleCI, and other platforms, helping you understand the landscape and choose the right tool.

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GitLab CI/CD

GitLab CI/CD is a built-in CI/CD solution that is part of GitLab — no separate tool or integration needed.

Key Features

• Integrated — CI/CD lives alongside code, issues, and container registry
• Auto DevOps — automatic pipeline detection and configuration
• Self-hosted or cloud — run GitLab on your own servers or use gitlab.com
• Container Registry — built-in Docker image registry
• Environments — track deployments across environments
• Review Apps — deploy each merge request to its own environment

.gitlab-ci.yml

GitLab pipelines are defined in a .gitlab-ci.yml file at the root of the repository:

stages:
  - build
  - test
  - deploy

variables:
  NODE_ENV: production

build:
  stage: build
  image: node:20-alpine
  script:
    - npm ci
    - npm run build
  artifacts:
    paths:
      - dist/
    expire_in: 1 hour

test:
  stage: test
  image: node:20-alpine
  script:
    - npm ci
    - npm run lint
    - npm test -- --coverage
  coverage: '/All files[^|]*\|[^|]*\s+([\d.]+)/'

deploy:
  stage: deploy
  image: alpine:latest
  script:
    - ./deploy.sh
  only:
    - main
  environment:
    name: production
    url: https://myapp.example.com

GitLab Runners

GitLab uses runners to execute jobs. Runners can be:

Type	Description
Shared runners	Provided by GitLab (cloud)
Group runners	Shared across projects in a group
Project runners	Dedicated to a single project
Self-hosted	Installed on your own infrastructure

GitLab CI vs GitHub Actions

Feature	GitLab CI	GitHub Actions
Config file	.gitlab-ci.yml	.github/workflows/*.yml
Runner types	Shared, group, project	GitHub-hosted, self-hosted
Container registry	Built-in	GHCR (separate)
Auto DevOps	Yes	No (manual config)
Review apps	Built-in	Requires setup
Marketplace	Fewer templates	Large marketplace
Self-hosting	Full GitLab instance	Only runners
Free tier	400 min/month	2,000 min/month

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Jenkins

Jenkins is the oldest and most widely deployed CI/CD server. It is open-source and highly extensible.

Key Features

• Extensible — 1,800+ plugins for every tool and service
• Self-hosted — full control over infrastructure
• Pipeline as code — Jenkinsfile (Groovy DSL)
• Distributed builds — master/agent architecture
• Legacy support — widely used in enterprises

Jenkinsfile

pipeline {
    agent any

    environment {
        NODE_ENV = 'production'
    }

    stages {
        stage('Build') {
            steps {
                sh 'npm ci'
                sh 'npm run build'
            }
        }

        stage('Test') {
            steps {
                sh 'npm test'
            }
        }

        stage('Deploy') {
            when {
                branch 'main'
            }
            steps {
                sh './deploy.sh'
            }
        }
    }

    post {
        always {
            junit 'test-results/*.xml'
        }
        failure {
            mail to: 'team@example.com',
                 subject: "Build Failed: ${env.JOB_NAME}",
                 body: "Check: ${env.BUILD_URL}"
        }
    }
}

When to Use Jenkins