Devops Cicd

DevOps & CI/CD Skill

Patterns for pipelines, containers, and deployment.

WHEN_TO_USE

Apply this skill when configuring CI/CD pipelines, writing Dockerfiles, setting up GitHub Actions workflows, or preparing deployment checklists. Reference the patterns here before creating new pipeline or container configurations.

GitHub Actions Workflow Pattern

name: CI

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

jobs:
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version-file: '.nvmrc'
          cache: 'npm'
      - run: npm ci
      - run: npm run lint

  test:
    runs-on: ubuntu-latest
    needs: lint
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version-file: '.nvmrc'
          cache: 'npm'
      - run: npm ci
      - run: npm test -- --coverage
      - uses: actions/upload-artifact@v4
        with:
          name: coverage
          path: coverage/

  build:
    runs-on: ubuntu-latest
    needs: test
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version-file: '.nvmrc'
          cache: 'npm'
      - run: npm ci
      - run: npm run build

Key Practices

• Pin action versions to specific commits or major tags (@v4).
• Use concurrency to cancel superseded runs.
• Cache dependencies (cache: 'npm', cache: 'pip').
• Run lint before test, test before build. Fail fast.

Docker Best Practices

# Multi-stage build
FROM node:22-slim AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci --production=false
COPY . .
RUN npm run build

FROM node:22-slim AS runner
WORKDIR /app
RUN addgroup --system app && adduser --system --ingroup app app
COPY --from=builder /app/dist ./dist
COPY --from=builder /app/node_modules ./node_modules
COPY --from=builder /app/package.json ./
USER app
EXPOSE 3000
HEALTHCHECK --interval=30s --timeout=3s CMD wget -q --spider http://localhost:3000/health || exit 1
CMD ["node", "dist/index.js"]

Rules

• Use multi-stage builds to minimize image size.
• Run as non-root user.
• Include .dockerignore (node_modules, .git, .env, tests).
• Pin base image versions. Never use latest.
• Add HEALTHCHECK for orchestrator integration.
• One process per container.

Environment Configuration

.env.example          # Template with all required variables (committed)
.env                  # Local overrides (gitignored)
.env.test             # Test environment (gitignored)

Rules

• Never commit .env files with real values.
• Document every variable in .env.example with comments.
• Validate all environment variables at startup — fail fast if missing.
• Use typed config objects, not raw process.env access throughout code.

Deployment Checklist

Pre-deploy:

• All tests pass on CI.
• No critical or high vulnerability alerts.
• Database migrations tested and reversible.
• Environment variables configured for target environment.
• Feature flags set correctly.

Deploy:

• Deploy to staging first. Verify.
• Deploy to production with rollback plan ready.
• Monitor error rates and latency for 15 minutes post-deploy.

Post-deploy:

• Verify health checks pass.
• Run smoke tests against production.
• Notify team of successful deployment.