With Helm

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The chart is published on GHCR as an OCI artifact, with the same version as the app and the image. It is also listed on Artifact Hub.

Needs	Installs into	You get
`kubectl`, Helm 4 and a cluster	the namespace you choose	a ServiceAccount, a Service (`LoadBalancer` by default) and a Deployment with 2 pods, all named `hello-kubernetes-<release name>`. An Ingress or an HTTPRoute, if you turn one on.

Install

Install the chart as the release hello-world, in a new hello-kubernetes namespace:

helm install hello-world oci://ghcr.io/paulbouwer/charts/hello-kubernetes \
  --namespace hello-kubernetes --create-namespace \
  --wait

You see STATUS: deployed, and notes that say how to reach the app for the Service type you chose.

To install a specific version, add --version, for example --version 1.11.0. Without it, Helm installs the newest release.

Set values

Set values with --set, or put them in a values file:

--set
values.yaml

helm install custom-message oci://ghcr.io/paulbouwer/charts/hello-kubernetes \
  --namespace hello-kubernetes --create-namespace \
  --set-string message="I just deployed this on Kubernetes!" \
  --set service.type=ClusterIP \
  --wait

message: "I just deployed this on Kubernetes!"
service:
  type: ClusterIP

With a values file, install with --values values.yaml. Use --set-string for the message, so Helm keeps it as text even if it looks like a number or yes. In a values file, quote it.

--set and --set-string read some characters as syntax, even inside quotes: a comma starts the next value, braces make a list, and a backslash escapes the next character. Put a backslash before each of them, as in --set-string message='Hello\, Kubernetes!', or put text like this in a values file. The config builder escapes them for you.

Helm checks your values against the chart’s schema on every install and upgrade. A misspelled or unknown key, a wrong type or a value that isn’t allowed stops the install, with a message that names the value, for example additional properties 'pathPrefx' not allowed. Editors that read JSON Schema show each value’s description and allowed values.

Every value is in the values reference. To see them from the chart itself:

helm show values oci://ghcr.io/paulbouwer/charts/hello-kubernetes

Verify

Forward a local port to the Service:

kubectl port-forward service/hello-kubernetes-custom-message 8080:80 --namespace hello-kubernetes

Open http://localhost:8080/. You see I just deployed this on Kubernetes!. With a LoadBalancer Service, kubectl get service shows its external address; see where the external address works.

To check that the chart is the one this repo published, verify its signed provenance. helm pull prints the chart’s digest:

helm pull oci://ghcr.io/paulbouwer/charts/hello-kubernetes --version 1.11.0
gh attestation verify oci://ghcr.io/paulbouwer/charts/hello-kubernetes@<digest> --repo paulbouwer/hello-kubernetes

Upgrade

Change a value, or move to a newer chart, with helm upgrade. --reset-then-reuse-values starts from the new chart’s defaults, then applies the values you set before:

helm upgrade custom-message oci://ghcr.io/paulbouwer/charts/hello-kubernetes \
  --namespace hello-kubernetes --reset-then-reuse-values \
  --set-string message="Upgraded!" \
  --wait

The pods are replaced one at a time, and the page then shows Upgraded!.

Use --reset-then-reuse-values, not --reuse-values. --reuse-values also reuses the old chart’s defaults, so a value that is new in the chart is missing, and the upgrade can fail. Moving from 1.10, it does. See Upgrading from 1.10.

Uninstall

helm uninstall hello-world --namespace hello-kubernetes
helm uninstall custom-message --namespace hello-kubernetes
kubectl delete namespace hello-kubernetes

helm list --all-namespaces shows the releases, if you don’t remember their names.

Requirements

Helm 4. The chart is tested with Helm 4 only.
Kubernetes 1.35 or newer. CI tests 1.35 and the current release, on kind and k3d.
linux/amd64 or linux/arm64 nodes.