CI/CD: automate your application deployment

CI/CD: automate application deployment — From commit to production: tests, build, security gates, approvals and rollback.

Key takeaways (TL;DR) Pipeline: Install → Lint → Test → Build → Scan → Deploy (staging → prod with approval). Secrets in CI secret store; prefer OIDC + vault/cloud secret manager over long‑lived keys. Idempotency and rollback via versioned artifacts or immutable Docker images. Observability: metrics, logs and alerts (SLI/SLO). Quality gates on tests/coverage.

CI/CD automates tests, builds and deployments so you can ship faster and safer. This guide proposes a reference pipeline, best practices and concrete examples withGitHub ActionsandGitLab CI.

Platforms & key tools

GitHub Actions— YAML workflows, OIDC to cloud:github.com/features/actions
GitLab CI— .gitlab-ci.yml, environments & approvals:docs.gitlab.com/ee/ci
Jenkins— declarative pipelines:jenkins.io/doc
Docker& registries (GHCR, GitLab Registry, ECR, GCR) for reproducible artifacts.
Kubernetes+Argo CD/Flux(GitOps) for declarative deployments.
Quality/Security:ESLint,Jest/PHPUnit,SonarQube,Trivy(images),Dependabot/Renovate.

Reference pipeline

Install deps +cache(npm/pnpm/composer).
Quality:lint,format,unit testsandcoverage.
Security:SCA(deps),SAST(code),image scanif Docker.
Build: artifact (zip) or taggedDocker image(app:1.2.3+sha).
Stagingdeploy (auto) →e2e/smokechecks.
Approval gate →productiondeploy (manual) +post‑deploy verification.

GitHub Actions example (Node)

GitLab CI example (Docker + Kubernetes)

Environments, secrets and security

Useenvironments(staging, preprod, prod) withURLsandaccess rules.
Prefer OIDC +cloud roles(AWS/GCP/Azure) over long‑lived keys; rotate secrets.
Enableapprovals,code owners,branch protectionand security scans.

Deployment strategies

Blue/Green: two environments; switch traffic after validation.
Canary: progressively shift traffic (1% → 100%).
Rolling: gradually replace pods/instances.
Feature flagsto decouple release from deploy.

Tools mentioned GitHub Actions, GitLab CI, Jenkins, Docker, Kubernetes, Argo CD/Flux, SonarQube, Trivy, Dependabot/Renovate.