CI/CD pipeline with GitLab CI

                  stages:
  - lint
  - test
  - build
  - deploy

variables:
  NODE_VERSION: "20"
  DOCKER_DRIVER: overlay2
  IMAGE_TAG: $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA

default:
  image: node:${NODE_VERSION}-alpine
  cache:
    key:
      files:
        - package-lock.json
    paths:
      - node_modules/

# Templates
.deploy_template: &deploy
  image: bitnami/kubectl:latest
  before_script:
    - kubectl config use-context $KUBE_CONTEXT

# Lint
lint:
  stage: lint
  script:
    - npm ci
    - npm run lint
    - npm run format:check
  rules:
    - if: $CI_PIPELINE_SOURCE == "merge_request_event"
    - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH

# Test with coverage
test:
  stage: test
  services:
    - name: postgres:16-alpine
      alias: db
  variables:
    POSTGRES_DB: test
    POSTGRES_PASSWORD: test
    DATABASE_URL: postgres://postgres:test@db:5432/test
  script:
    - npm ci
    - npm test -- --coverage
  coverage: '/All files[^|]*|[^|]* +([d.]+)/'
  artifacts:
    when: always
    reports:
      junit: junit.xml
      coverage_report:
        coverage_format: cobertura
        path: coverage/cobertura-coverage.xml
    paths:
      - coverage/
    expire_in: 7 days

# Build Docker image
build:
  stage: build
  image: docker:24
  services:
    - docker:24-dind
  before_script:
    - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
  script:
    - docker build -t $IMAGE_TAG .
    - docker push $IMAGE_TAG
  rules:
    - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH

# Deploy to staging
deploy_staging:
  <<: *deploy
  stage: deploy
  script:
    - kubectl set image deployment/web-app web-app=$IMAGE_TAG -n staging
    - kubectl rollout status deployment/web-app -n staging --timeout=300s
  environment:
    name: staging
    url: https://staging.example.com
  rules:
    - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH

# Deploy to production (manual gate)
deploy_production:
  <<: *deploy
  stage: deploy
  script:
    - kubectl set image deployment/web-app web-app=$IMAGE_TAG -n production
    - kubectl rollout status deployment/web-app -n production --timeout=300s
  environment:
    name: production
    url: https://app.example.com
  rules:
    - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH
      when: manual
  needs:
    - deploy_staging