DevOps Platform

GitLab

Overview

GitLab is a comprehensive DevOps platform that provides Git repository management along with integrated CI/CD, security scanning, and project management tools. Founded in 2011, GitLab offers both cloud-hosted (GitLab.com) and self-hosted solutions, making it popular among enterprises that require on-premises deployment. GitLab emphasizes the complete DevOps lifecycle, from planning and development to security and monitoring.

Details

GitLab combines version control with a full DevOps toolchain in a single application. Unlike GitHub's marketplace approach, GitLab provides built-in features for the entire software development lifecycle, including issue tracking, merge requests, CI/CD pipelines, container registry, security scanning, and monitoring.

The platform offers three deployment options: GitLab.com (SaaS), GitLab Self-Managed (on-premises), and GitLab Dedicated (single-tenant cloud). This flexibility allows organizations to choose the deployment model that best fits their security and compliance requirements.

GitLab's CI/CD system is one of its strongest features, offering parallel execution, auto-scaling runners, and integrated deployment tools. The platform also includes advanced security features like SAST, DAST, dependency scanning, and container scanning as part of its DevSecOps approach.

Key differentiators include built-in container registry, Kubernetes integration, advanced merge request analytics, and comprehensive project templates for various technology stacks.

Advantages and Disadvantages

Advantages

• Complete DevOps Platform: All-in-one solution from planning to monitoring
• Self-Hosting Option: Full control with on-premises deployment
• Built-in CI/CD: Powerful pipeline system without external tools
• Security-First Approach: Integrated security scanning and compliance
• Flexible Deployment: SaaS, self-managed, or dedicated options
• Strong Enterprise Features: Advanced user management and compliance
• Open Source Core: Community edition available for free
• Kubernetes Integration: Native container orchestration support

Disadvantages

• Resource Intensive: Self-hosted instances require significant resources
• Complex Setup: Initial configuration can be overwhelming
• Learning Curve: Many features require time to master
• Cost Scaling: Enterprise features can become expensive
• Performance Issues: Large instances may experience slower performance
• Limited Third-Party Ecosystem: Fewer integrations than competitors

Reference Pages

• GitLab Official Website
• GitLab Documentation
• GitLab CI/CD Documentation
• GitLab API Documentation
• GitLab University
• GitLab Community

Code Examples

Basic GitLab Workflow

# Clone a GitLab repository
git clone https://gitlab.com/user/project.git

# Create a new branch for feature development
git checkout -b feature/new-feature

# Make changes and commit
git add .
git commit -m "Add new feature implementation"

# Push branch to GitLab
git push origin feature/new-feature

# Create merge request via web interface or GitLab CLI

GitLab CI/CD Pipeline Configuration

# .gitlab-ci.yml
stages:
  - test
  - build
  - deploy

variables:
  NODE_VERSION: "18"
  DOCKER_DRIVER: overlay2

# Test stage
test:
  stage: test
  image: node:${NODE_VERSION}
  cache:
    paths:
      - node_modules/
  before_script:
    - npm ci
  script:
    - npm run test
    - npm run lint
  coverage: '/Coverage: \d+\.\d+%/'
  artifacts:
    reports:
      coverage_report:
        coverage_format: cobertura
        path: coverage/cobertura-coverage.xml

# Build stage
build:
  stage: build
  image: docker:latest
  services:
    - docker:dind
  before_script:
    - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
  script:
    - docker build -t $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA .
    - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
  only:
    - main
    - develop

# Deploy to staging
deploy_staging:
  stage: deploy
  image: alpine:latest
  before_script:
    - apk add --no-cache curl
  script:
    - echo "Deploying to staging environment"
    - curl -X POST "$STAGING_WEBHOOK_URL" -H "Authorization: Bearer $STAGING_TOKEN"
  environment:
    name: staging
    url: https://staging.example.com
  only:
    - develop

# Deploy to production
deploy_production:
  stage: deploy
  image: alpine:latest
  script:
    - echo "Deploying to production environment"
    - curl -X POST "$PRODUCTION_WEBHOOK_URL" -H "Authorization: Bearer $PRODUCTION_TOKEN"
  environment:
    name: production
    url: https://example.com
  when: manual
  only:
    - main

GitLab Container Registry Usage

# Login to GitLab Container Registry
docker login registry.gitlab.com

# Build and tag image
docker build -t registry.gitlab.com/username/project:latest .

# Push image to GitLab registry
docker push registry.gitlab.com/username/project:latest

# Pull image from GitLab registry
docker pull registry.gitlab.com/username/project:latest

# Use in GitLab CI/CD
# Images are automatically available as $CI_REGISTRY_IMAGE

GitLab API Usage

# Get personal access token from GitLab settings
GITLAB_TOKEN="your-access-token"
GITLAB_URL="https://gitlab.com"

# List projects
curl --header "PRIVATE-TOKEN: $GITLAB_TOKEN" "$GITLAB_URL/api/v4/projects"

# Create a new project
curl --header "PRIVATE-TOKEN: $GITLAB_TOKEN" \
     --header "Content-Type: application/json" \
     --data '{"name":"my-project","visibility":"private"}' \
     "$GITLAB_URL/api/v4/projects"

# Create merge request
curl --header "PRIVATE-TOKEN: $GITLAB_TOKEN" \
     --header "Content-Type: application/json" \
     --data '{
       "source_branch":"feature-branch",
       "target_branch":"main",
       "title":"Add new feature"
     }' \
     "$GITLAB_URL/api/v4/projects/PROJECT_ID/merge_requests"

GitLab Runner Configuration

# .gitlab-runner/config.toml
concurrent = 4
check_interval = 0

[session_server]
  session_timeout = 1800

[[runners]]
  name = "docker-runner"
  url = "https://gitlab.com/"
  token = "your-runner-token"
  executor = "docker"
  [runners.custom_build_dir]
  [runners.cache]
    [runners.cache.s3]
    [runners.cache.gcs]
    [runners.cache.azure]
  [runners.docker]
    tls_verify = false
    image = "docker:latest"
    privileged = true
    disable_entrypoint_overwrite = false
    oom_kill_disable = false
    disable_cache = false
    volumes = ["/cache", "/var/run/docker.sock:/var/run/docker.sock"]
    shm_size = 0

Security Scanning Integration

# Security scanning in .gitlab-ci.yml
include:
  - template: Security/SAST.gitlab-ci.yml
  - template: Security/Secret-Detection.gitlab-ci.yml
  - template: Security/Dependency-Scanning.gitlab-ci.yml
  - template: Security/Container-Scanning.gitlab-ci.yml

# Custom SAST configuration
sast:
  variables:
    SAST_EXCLUDED_PATHS: "spec, test, tests, tmp"
    SAST_BANDIT_EXCLUDED_PATHS: "*/tests/*"

# Container scanning for Docker images
container_scanning:
  variables:
    CS_IMAGE: $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA

GitLab Pages Deployment

# Deploy static site to GitLab Pages
pages:
  stage: deploy
  image: node:18
  script:
    - npm ci
    - npm run build
    - cp -r dist/ public/
  artifacts:
    paths:
      - public
  only:
    - main

# Custom domain configuration
# Add CNAME record pointing to username.gitlab.io
# Configure in GitLab project settings

Issue and Merge Request Templates

<!-- .gitlab/issue_templates/Bug.md -->
## Bug Report

### Description
A clear and concise description of the bug.

### Steps to Reproduce
1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

### Expected Behavior
A clear description of what you expected to happen.

### Screenshots
If applicable, add screenshots to help explain your problem.

### Environment
- OS: [e.g. iOS]
- Browser: [e.g. chrome, safari]
- Version: [e.g. 22]

/label ~bug ~needs-investigation

<!-- .gitlab/merge_request_templates/Default.md -->
## Merge Request

### Description
Brief description of the changes made.

### Changes Made
- [ ] Feature A
- [ ] Bug fix B
- [ ] Documentation update

### Testing
- [ ] Unit tests pass
- [ ] Integration tests pass
- [ ] Manual testing completed

### Checklist
- [ ] Code follows style guidelines
- [ ] Self-review completed
- [ ] Documentation updated
- [ ] Breaking changes documented

/label ~feature