Ship changes with Git, CI/CD and GitOps

$ run as a normal user# run as root (or with sudo)

Skills in this chapter

Git, CI/CD and GitOps — 7

Git — the start of every change

git keeps the history; branches and pull requests let the team review every change.

$git switch -c feat/health-check
$git commit -am "Add /health endpoint"
$git push -u origin feat/health-check
$git tag -a v1.4.0 -m "release 1.4.0" && git push --tags

Good practice:

Small pull requests; protected main; tags for releases.

6.2

GitHub CLI — PRs and Actions from the terminal

gh opens PRs, watches pipeline runs and reads the logs of failed jobs.

$gh pr create --fill
$gh run watch
$gh run view --log-failed
$gh workflow run deploy.yml -f environment=staging

6.3

act — test GitHub Actions locally

act runs your workflow in Docker on your machine, so you do not push 20 times to fix a pipeline.

$act -l
$act pull_request -j test
$act --secret-file .secrets

6.4

GitLab Runner and Jenkins — pipelines in companies

gitlab-runner runs .gitlab-ci.yml jobs; jenkins runs Jenkinsfile pipelines. You meet both in many companies.

#gitlab-runner register --url https://gitlab.com --token glrt-xxxx --executor docker --docker-image alpine:3.20 --non-interactive
#gitlab-runner verify
#systemctl status jenkins

6.5

Argo CD and Flux — GitOps

argocd and flux watch a Git repo and make the cluster match it — deploy = merge a pull request; rollback = revert.

$argocd app create shop --repo https://github.com/acme/gitops --path apps/shop/prod --dest-server https://kubernetes.default.svc --dest-namespace shop --sync-policy automated
$argocd app get shop
$flux get kustomizations
$flux reconcile kustomization apps --with-source

6.6

Build a pipeline with clear stages

Every good pipeline has the same stages; fast checks first.

Lint and unit test (make lint test) — fails in 1–2 minutes.
Build the image once, tag it with the commit SHA.
Push to the registry.
Deploy to staging — change the tag in the GitOps repo.
Smoke and load test staging (curl -f, k6).
Promote the same image to production (PR or manual approval).

Remember

A pipeline that takes more than 10 minutes makes people skip it. Cache, run jobs in parallel, and keep slow tests on a schedule.

Ship changes with Git, CI/CD and GitOps

All commands in this chapter