GitLab CI/CD

GitLab CI/CD is an all-in-one DevOps solution that combines a Git version control system with continuous integration and continuous deployment capabilities. Unlike solutions requiring multiple tools, GitLab offers a unified experience from code to production. This integrated approach reduces operational complexity and improves traceability across the entire software lifecycle.

GitLab CI/CD Fundamentals

• Pipeline as Code: declarative configuration via .gitlab-ci.yml file versioned with source code
• Distributed runners: execution agents capable of running on various infrastructures (cloud, on-premise, Kubernetes)
• Modular architecture: stages, jobs, and artifacts enabling complex workflow structuring
• Native integration: repository management, issues, merge requests, and CI/CD in a single interface

Strategic Benefits

• Complete DevOps cycle visibility from planning through post-deployment monitoring
• Infrastructure cost reduction through intelligent caching and runner sharing
• Integrated security with native vulnerability scanning, compliance, and secrets management
• Horizontal scalability supporting thousands of simultaneous pipelines
• Auto DevOps: preconfigured templates for automatic deployment without manual configuration
• Compliance and audit: complete traceability of deployments and code changes

GitLab CI/CD Pipeline Example

stages:
  - build
  - test
  - security
  - deploy

variables:
  DOCKER_DRIVER: overlay2
  NODE_ENV: production

# Template to avoid repetition
.node-template: &node-template
  image: node:18-alpine
  cache:
    key: ${CI_COMMIT_REF_SLUG}
    paths:
      - node_modules/
  before_script:
    - npm ci --prefer-offline

build:app:
  <<: *node-template
  stage: build
  script:
    - npm run build
    - npm run lint
  artifacts:
    paths:
      - dist/
    expire_in: 1 week
  only:
    - merge_requests
    - main

test:unit:
  <<: *node-template
  stage: test
  coverage: '/Statements\s*:\s*(\d+\.\d+)%/'
  script:
    - npm run test:coverage
  artifacts:
    reports:
      coverage_report:
        coverage_format: cobertura
        path: coverage/cobertura-coverage.xml

security:sast:
  stage: security
  image: returntocorp/semgrep
  script:
    - semgrep --config=auto --json -o sast-report.json
  artifacts:
    reports:
      sast: sast-report.json
  allow_failure: true

deploy:staging:
  stage: deploy
  image: alpine:latest
  before_script:
    - apk add --no-cache curl
  script:
    - |
      curl -X POST "$DEPLOY_WEBHOOK_URL" \
        -H "Authorization: Bearer $DEPLOY_TOKEN" \
        -d "{\"environment\":\"staging\",\"version\":\"$CI_COMMIT_SHA\"}"
  environment:
    name: staging
    url: https://staging.example.com
    on_stop: stop:staging
  only:
    - main

stop:staging:
  stage: deploy
  script:
    - echo "Stopping staging environment"
  when: manual
  environment:
    name: staging
    action: stop

deploy:production:
  stage: deploy
  extends: deploy:staging
  script:
    - |
      curl -X POST "$DEPLOY_WEBHOOK_URL" \
        -H "Authorization: Bearer $DEPLOY_TOKEN" \
        -d "{\"environment\":\"production\",\"version\":\"$CI_COMMIT_SHA\"}"
  environment:
    name: production
    url: https://example.com
  only:
    - tags
  when: manual

Structured Implementation

1. Install and configure GitLab Runner (Docker, Kubernetes, or shell executor based on infrastructure)
2. Create .gitlab-ci.yml file at project root with stages and jobs definition
3. Configure CI/CD variables (Settings > CI/CD > Variables) to store secrets and configuration
4. Define environments and their URLs in Deployments section to enable tracking
5. Implement merge request pipelines to validate code before merging
6. Configure branch protection rules and required approvals
7. Enable security features (SAST, DAST, dependency scanning) via templates
8. Set up monitoring with Prometheus/Grafana integration to track metrics

Ecosystem and Integrations

• Kubernetes: native deployment with Auto DevOps and cluster integration
• Terraform: infrastructure provisioning with state stored in GitLab
• Jira/ServiceNow: bidirectional synchronization of issues and incidents
• Slack/Teams: real-time notifications on pipeline status
• HashiCorp Vault: centralized secrets management with automatic rotation
• Prometheus/Grafana: CI/CD metrics and deployment observability
• Trivy/Snyk: container and dependency vulnerability analysis

GitLab CI/CD transforms team velocity by eliminating silos between development and operations. The all-in-one approach reduces licensing and training costs while improving collaboration through unified visibility. Large enterprises particularly appreciate compliance features, self-hosting for data sovereignty, and proven scalability across thousands of simultaneous projects.