CI/CD Pipeline Explained: From Git Commit to Kubernetes Deploy (Docker + GitHub Actions)

A CI/CD pipeline is the path from a git commit to a running service your customers can hit. Without it, teams ship by hand: build locally, push an image, edit YAML, hope the cluster agrees. With it, every merge can run tests, produce an immutable Docker image, and roll out to Kubernetes with a repeatable process.

This guide explains a production-shaped pipeline for NestJS microservices and SaaS platforms — and how Cyber Infoware kits wire GitHub Actions, Docker, and Kubernetes so you start from a working delivery path.

CI vs CD in one minute

• Continuous Integration (CI) — on every pull request: install, lint, unit/integration tests, build the app
• Continuous Delivery — produce a deployable artifact (Docker image) ready for staging/production
• Continuous Deployment (CD) — automatically apply that artifact to a cluster (with gates and rollbacks)

A practical GitHub Actions + Docker + Kubernetes flow

1. Developer opens a PR — Actions runs tests against NestJS services.
2. Merge to main — pipeline builds a Docker image tagged by git SHA.
3. Image is pushed to a registry (GHCR, ECR, etc.).
4. Deploy job updates Kubernetes manifests / Helm values to the new tag.
5. Cluster pulls the image; Deployment does a rolling update across Pods.
6. Health probes fail? Kubernetes stops the rollout; you roll back to the previous tag.

Why image tags matter

Always deploy an immutable tag (`sha-abc123`), not floating `latest`. That is how you reproduce incidents and roll back safely. SaaS control planes with many services need this discipline — one bad gateway image should not force a mystery rebuild.

Pipeline design tips for multi-service SaaS

• One workflow per service (or a matrix) so a catalog change does not rebuild billing
• Cache node_modules / Docker layers to keep PR feedback under a few minutes
• Separate staging and production environments with explicit approvals for prod
• Smoke-test the API gateway and Keycloak login after deploy — not only unit tests
• Emit OpenTelemetry traces in the app so deploy regressions show up in Grafana quickly

What “done” looks like

You can merge a NestJS change, watch Actions go green, and see the new tag on a Kubernetes Deployment without SSH. That is the delivery bar modern SaaS buyers quietly assume. Explore packages on cyberinfoware.com or contact us to match a kit to your pipeline goals.