How to deploy Helm charts to Kubernetes from CI

What and why

Helm packages Kubernetes manifests into versioned, parameterized charts. Instead of hand-editing YAML per environment, you template it once and supply values. This tutorial deploys a chart to Kubernetes from CI with per-environment overrides.

Prerequisites

• A Kubernetes cluster and credentials.
• Helm installed.
• A containerized app and a CI pipeline.

Steps

1. Create a chart

helm create web

This scaffolds a chart with templates, a values.yaml, and metadata.

2. Parameterize templates with values

Reference values in templates so they vary by environment:

image:
  repository: ghcr.io/acme/web
  tag: "{{ .Values.image.tag }}"
replicaCount: {{ .Values.replicaCount }}

Defaults live in values.yaml.

3. Add per-environment value files

Create values-staging.yaml and values-prod.yaml with only the differences, such as replica counts and resource limits. Keep shared defaults in the base file.

4. Authenticate CI to the cluster

Provide a kubeconfig or cloud credentials as CI secrets, scoped to the target namespace. The pipeline needs permission to manage releases in that namespace only.

5. Run helm upgrade in CI

      - run: |
          helm upgrade --install web ./web \
            -f values-prod.yaml \
            --set image.tag=${{ github.sha }} \
            --namespace web --wait

upgrade --install creates the release if absent and upgrades it otherwise; --wait blocks until resources are ready.

Verification

Run helm status web -n web and confirm the release is deployed. Check kubectl get pods -n web shows the new image tag. Roll back with helm rollback web to confirm release history is tracked.

Next Steps

Lint and template-test charts in CI before deploy. Publish charts to a chart repository for reuse. Combine with a GitOps controller so Helm releases are reconciled from Git.