Lint and Template Gates in CI
Failing the build on invalid charts early.
Lint and Template Gates in CI is a free Helm Academy lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Helm Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Catch Bugs Before the Cluster
A broken chart should fail your pipeline, not your production cluster. CI gates let you reject bad charts the moment a pull request opens. 🛡️
helm lint Is Your First Gate
The command helm lint runs static checks on a chart: it verifies the structure, required fields, and common best-practice issues without touching any cluster.
helm lint ./mychartWhat lint Actually Checks
Lint flags a missing Chart.yaml field, an unparseable template, or an icon that is not a URL. It is fast and needs no Kubernetes connection.
Strict Mode Turns Warnings Into Failures
Add --strict so lint warnings also fail the run. In CI you want the build red on anything questionable, not a silent warning nobody reads.
helm lint --strict ./mychartLint With Real Values
Pass -f to lint against the values a release will actually use. A chart can be valid empty yet break once your production values are merged in.
helm lint -f values-prod.yaml ./mychartThe Second Gate: helm template
After lint passes, run helm template to render every manifest locally. If templating fails, the pipeline stops before anything reaches Kubernetes.
helm template ./mychart > rendered.yamlWhy template Catches More
Lint is shallow; helm template fully evaluates your Go template logic. A typo in a range or a nil value surfaces here, not at deploy time.
Exit Codes Drive the Gate
Both commands return a non-zero exit code on failure. CI runners read that code automatically and mark the job failed, blocking the merge.
Validate Rendered YAML Against the API
Pipe the rendered output into kubeval or kubeconform to confirm it matches real Kubernetes schemas. This catches a wrong field name early.
helm template ./mychart | kubeconform -strictWire It Into a CI Step
Chain the gates in one job so a failure short-circuits the rest. In most runners && stops on the first non-zero exit, keeping feedback fast.
helm lint --strict ./mychart && helm template ./mychart > /dev/nullRun Gates on Every Pull Request
Trigger these checks on each pull request, not just on merge. Reviewers see a green check that proves the chart still renders correctly.
Quick Check
Which gate fully evaluates your Go template logic to catch a bad range expression?
Recap: Fail Fast in CI
Gate every change with helm lint --strict then helm template, optionally schema-checking the output. Bad charts fail the build, never the cluster. ✅
Frequently asked questions
Is the “Lint and Template Gates in CI” lesson free?
Yes — the full text of “Lint and Template Gates in CI” is free to read here on the web, and the Helm Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Helm Academy course, upgrade to CoddyKit PRO.
What will I learn in “Lint and Template Gates in CI”?
Failing the build on invalid charts early. You practise Helm Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Helm Academy?
No prior experience is required. Helm Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Lint and Template Gates in CI” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Helm Academy lesson?
Yes. Every Helm Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.