GitHub Actions vs GitLab CI: Complete Comparison of CI/CD Tools

Introduction

In modern software development, Continuous Integration and Continuous Delivery (CI/CD) tools are essential for automating testing, building, and deploying applications. GitHub Actions and GitLab CI are two of the most popular platforms for implementing CI/CD pipelines. In this comprehensive article, I'll provide a detailed comparison with practical, real-world examples.

What are GitHub Actions and GitLab CI?

GitHub Actions is GitHub's native CI/CD solution, introduced in 2019, which allows you to automate workflows directly from your GitHub repositories. It offers seamless integration with the GitHub ecosystem and provides a marketplace with thousands of pre-built actions.

GitLab CI/CD is the continuous integration tool integrated into GitLab, available since 2012, forming part of GitLab's complete DevOps ecosystem. It's known for its maturity, enterprise features, and comprehensive pipeline visualization capabilities.

Feature Comparison

1. Syntax and Configuration

GitHub Actions uses YAML files in the .github/workflows/ folder:

name: GitHub Actions Demo
on:
  push:
    branches: [ main, develop ]
  pull_request:
    branches: [ main ]

jobs:
  test:
    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v4

    - name: Set up Node.js
      uses: actions/setup-node@v4
      with:
        node-version: '20'

    - name: Install dependencies
      run: npm ci

    - name: Run tests
      run: npm test

    - name: Run linter
      run: npm run lint

GitLab CI uses a .gitlab-ci.yml file in the repository root:

stages:
  - test
  - build
  - deploy

variables:
  NODE_VERSION: "20"

test:
  stage: test
  image: node:${NODE_VERSION}
  before_script:
    - npm ci
  script:
    - npm test
    - npm run lint
  coverage: '/All files[^|]*\|[^|]*\s+([\d\.]+)/'
  only:
    - main
    - develop
    - merge_requests

Key Differences:

• GitHub Actions organizes by jobs and steps
• GitLab CI emphasizes stages for better pipeline visualization
• GitLab CI has built-in support for Docker images per job
• GitHub Actions uses marketplace actions for extended functionality

2. Runners and Execution Environment

GitHub Actions:

• GitHub-hosted runners (generous free tier)
• Self-hosted runners for custom environments
• Multiple operating systems: Ubuntu, Windows, macOS
• Event-based execution (push, PR, schedule, manual dispatch, etc.)
• Matrix builds for testing across multiple configurations
• Job dependencies with needs keyword

GitLab CI:

• Shared runners on GitLab.com
• Project-specific runners
• Group-level runners for organization-wide sharing
• Superior Kubernetes integration with native support
• More flexibility in runner configuration and tags
• Built-in Docker registry integration

3. Artifact Management

GitHub Actions:

build:
  needs: test
  runs-on: ubuntu-latest

  steps:
  - uses: actions/checkout@v4

  - name: Set up Node.js
    uses: actions/setup-node@v4
    with:
      node-version: '20'

  - name: Install dependencies
    run: npm ci

  - name: Build application
    run: npm run build

  - name: Upload artifact
    uses: actions/upload-artifact@v4
    with:
      name: build-files
      path: dist/
      retention-days: 7

GitLab CI:

build:
  stage: build
  image: node:${NODE_VERSION}
  before_script:
    - npm ci
  script:
    - npm run build
  artifacts:
    paths:
      - dist/
    expire_in: 1 week
    reports:
      junit: junit.xml
  needs:
    - test

Comparison:

• GitLab CI has native artifact support with built-in expiration
• GitHub Actions requires specific actions for upload/download
• GitLab CI offers better artifact reporting capabilities
• Both support cross-job artifact sharing

4. Deployment and Environments

GitHub Actions with deployment configuration:

deploy:
  needs: build
  runs-on: ubuntu-latest
  if: github.ref == 'refs/heads/main'
  environment:
    name: production
    url: https://production.example.com

  steps:
  - name: Download artifact
    uses: actions/download-artifact@v4
    with:
      name: build-files
      path: dist/

  - name: Deploy to production
    run: |
      echo "Deploying to production..."
      # Add your deployment commands here

GitLab CI with configured environments:

deploy_production:
  stage: deploy
  image: alpine:latest
  before_script:
    - apk add --no-cache openssh-client
  script:
    - echo "Deploying to production..."
    - echo "Add your deployment commands here"
  environment:
    name: production
    url: https://production.example.com
    on_stop: stop_production
  only:
    - main
  when: manual
  needs:
    - build

stop_production:
  stage: deploy
  script:
    - echo "Stopping production environment..."
  environment:
    name: production
    action: stop
  when: manual

Key Differences:

• GitLab CI has more advanced environment management
• GitLab CI supports environment stop actions for cleanup
• Both support manual deployments and environment URLs
• GitLab CI provides better environment tracking in the UI

5. Advanced Features

GitHub Actions Advantages:

• Marketplace Ecosystem: 20,000+ pre-built actions
• Matrix Builds: Easy configuration for multiple OS/versions
• Composite Actions: Reusable action creation
• OIDC Integration: Secure cloud provider authentication
• GitHub Integration: Native issues, PRs, and code insights

GitLab CI Advantages:

• Auto DevOps: Automatic CI/CD configuration
• Parent-Child Pipelines: Complex workflow orchestration
• Multi-Project Pipelines: Cross-repository dependencies
• Dynamic Environments: Environment per branch
• Built-in Container Registry: Integrated Docker registry
• Security Scanning: SAST, DAST, dependency scanning

Pros and Cons

GitHub Actions

Advantages:
✅ Perfect integration with GitHub ecosystem
✅ Extensive marketplace with thousands of reusable actions
✅ Generous free tier for hosted runners
✅ Modern, flexible syntax
✅ Excellent for open-source projects
✅ Easy to get started quickly
✅ Strong community support

Disadvantages:
❌ Less mature than GitLab CI (introduced in 2019)
❌ Basic coverage reporting
❌ Limited pipeline visualization options
❌ Tied to GitHub ecosystem
❌ Less granular control over runner configuration

GitLab CI/CD

Advantages:
✅ Complete DevOps platform (not just CI/CD)
✅ Robust enterprise features
✅ Superior pipeline visualization
✅ Detailed coverage reports
✅ Advanced environment management
✅ Auto DevOps and templates
✅ Built-in security scanning
✅ Better runner management

Disadvantages:
❌ Steeper learning curve
❌ More complex configuration for simple projects
❌ Shared runners have limited free capacity
❌ Requires more initial setup
❌ Less extensive action marketplace

Performance and Scalability

Build Speed

• GitHub Actions: Fast startup times, efficient for small to medium projects
• GitLab CI: Excellent caching mechanisms, better for large monorepos

Scalability

• GitHub Actions: Scales well with self-hosted runners
• GitLab CI: Superior enterprise scalability with runner fleets

Pricing Comparison

GitHub Actions

• Free: 2,000 minutes/month for private repos, unlimited for public
• Team: $4/user/month with 3,000 minutes
• Enterprise: $21/user/month with 50,000 minutes

GitLab CI

• Free: 400 minutes/month on shared runners
• Premium: $19/user/month with 10,000 minutes
• Ultimate: $99/user/month with 50,000 minutes

Recommended Use Cases

Use GitHub Actions if:

• Your code is hosted on GitHub
• You want quick setup and deployment
• You need to leverage the marketplace ecosystem
• You're working on open-source projects
• You prefer simplicity over advanced features
• Your team is already familiar with GitHub

Use GitLab CI if:

• You need a complete DevOps platform
• You require enterprise-grade features
• You work extensively with Kubernetes
• You need advanced environment management
• You want built-in security scanning
• You need fine-grained control over everything

Complete Example: Testing, Building, and Deployment Pipeline

You can find complete working examples in my repository:
🔗 Repository: https://github.com/RenzoFlv/Trabajo-Grupal-N-03

The repository includes:

• .github/workflows/github-actions-demo.yml: Complete pipeline with GitHub Actions including testing, building, and deployment stages
• .gitlab-ci.yml: Equivalent pipeline with GitLab CI featuring stages, artifacts, and environment configurations

What the Examples Demonstrate:

1. Automated Testing: Running unit tests and linters
2. Build Process: Compiling and packaging the application
3. Artifact Management: Storing and retrieving build outputs
4. Deployment Strategies: Different approaches for staging and production
5. Environment Configuration: Setting up and managing deployment targets

Migration Considerations

If you're considering migrating between platforms:

GitHub Actions → GitLab CI

• Convert workflow files to .gitlab-ci.yml
• Replace marketplace actions with Docker images or scripts
• Adjust artifact management syntax
• Reconfigure secrets and variables

GitLab CI → GitHub Actions

• Break down stages into jobs
• Find equivalent marketplace actions
• Convert before_script to setup steps
• Adjust environment configurations

Conclusion

Both GitHub Actions and GitLab CI are excellent CI/CD solutions, each with distinct strengths. GitHub Actions excels in simplicity and GitHub ecosystem integration, making it ideal for projects already on GitHub and teams seeking quick setup.

GitLab CI provides a comprehensive DevOps platform with advanced features, making it the choice for enterprises requiring extensive control and integrated security scanning.

Final Recommendation:

Choose based on:

• Where your code is hosted: Native integration matters
• Team size and complexity: Simple projects vs. enterprise needs
• Budget and resources: Consider the pricing tiers
• Team expertise: Learning curve varies significantly
• Required features: Advanced DevOps vs. quick CI/CD

The "best" tool depends entirely on your specific needs, team structure, and existing infrastructure. Both platforms continue to evolve, with GitHub Actions rapidly adding features and GitLab maintaining its position as a mature, feature-rich platform.

What's your experience?

Have you used either of these tools? What challenges did you face when implementing CI/CD? Share your thoughts in the comments!

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Related Resources:

• 📚 GitHub Actions Documentation
• 📚 GitLab CI/CD Documentation
• 💻 Example Repository with Both Configurations

Tags: #CICD #DevOps #GitHub #GitLab #Automation #Testing #ContinuousIntegration #ContinuousDelivery