CI/CD with GitHub Actions

CI/CD stands for Continuous Integration and Continuous Deployment. CI automatically tests every code push. CD automatically deploys code that passes tests. Together they let teams ship safely multiple times per day with full confidence.

01.Continuous Integration (CI) in Practice

Every push to any branch and every PR triggers the CI pipeline. A typical pipeline: checkout → install deps → lint (catch code style issues) → unit tests → integration tests → build → code coverage check. If any step fails, the whole job fails, PRs are blocked from merging, and the author is notified. CI ensures main is always working code.

Commit Timeline

a1b2c3d

init

b2c3d4e

feat

c3d4e5f

fix

d4e5f6a

HEAD

02.Continuous Deployment (CD) in Practice

CD runs only after CI passes on main. Typical steps: run full test suite → build Docker image or static bundle → push image to registry → update staging environment automatically → run smoke tests against staging → if all pass, deploy to production. With good test coverage, teams deploy dozens of times per day with zero manual steps.

Distributed Architecture

💻

Your Local

push / pull

☁️

GitHub (Remote)

push / pull

💻

Teammate's Local

Commands

commands — click to reveal output

mkdir -p .github/workflows

Create the GitHub Actions workflows directory

# .github/workflows/ci-cd.yml
# name: CI/CD Pipeline
# on:
#   push:
#     branches: [main]
#   pull_request:
#     branches: [main]
# jobs:
#   test:
#     runs-on: ubuntu-latest
#     steps:
#       - uses: actions/checkout@v4
#       - uses: actions/setup-node@v4
#         with: { node-version: '20' }
#       - run: npm ci
#       - run: npm run lint
#       - run: npm test
#   deploy:
#     needs: test
#     if: github.ref == 'refs/heads/main'
#     runs-on: ubuntu-latest
#     steps:
#       - uses: actions/checkout@v4
#       - run: npm ci && npm run build
#       - run: npx gh-pages -d dist

Full CI/CD pipeline example

git add .github/ && git commit -m "Add CI/CD pipeline"

Commit and push to activate the workflow

gh run list --workflow=ci-cd.yml

Check recent pipeline run results

▼ show output

gh run watch

Watch a pipeline run in real time in your terminal

KNOWLEDGE CHECK

What is the difference between CI and CD?

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