Educates Upgrade Kubernetes

Educates Kubernetes Version Upgrade Protocol

Upgrade Kubernetes version support based on $ARGUMENTS.

• If <new-version> is provided (e.g. 1.35), add support for that version.
• If --drop <old-version> is provided (e.g. --drop 1.31), remove that version.
• If no arguments, check https://www.downloadkubernetes.com/ for the latest stable versions and ask the user whether to keep 3 or 4 versions before proceeding.

We support versions for linux on amd64 and arm64 only.

Step 1: Gather Version Information

For the new kubectl version

1. Fetch checksums for both architectures:

   • https://dl.k8s.io/v{KUBECTL_VERSION}/kubernetes-client-linux-amd64.tar.gz.sha512
   • https://dl.k8s.io/v{KUBECTL_VERSION}/kubernetes-client-linux-arm64.tar.gz.sha512

   The full version string uses semantic versioning (e.g. 1.35.1). The short version is major.minor (e.g. 1.35).

2. Find the corresponding kind node image and SHA256 digest at https://github.com/kubernetes-sigs/kind/releases. Image format: kindest/node:v<K8S_VERSION>@sha256:<DIGEST>

Current versions

Read workshop-images/base-environment/Dockerfile to see which versions are currently installed and their RUN block format. Read client-programs/pkg/constants/kubernetes.go to see the current kind image map.

Step 2: Update All Files

You must update all of the following. Do not skip any.

workshop-images/base-environment/Dockerfile

Adding a new version — add a RUN <<EOF block following the existing pattern:

RUN <<EOF
    KUBECTL_VERSION=1.35.1
    KUBECTL_SHORT_VERSION=$(echo ${KUBECTL_VERSION} | cut -d. -f1,2)
    CHECKSUM_amd64="<sha512-for-amd64>"
    CHECKSUM_arm64="<sha512-for-arm64>"
    # ... rest of install block (copy from adjacent version block)
EOF

Removing an old version — delete the entire RUN <<EOF ... EOF block for that version.

Version mapping scripts (2 files with identical logic)

Update the case statement in both files to match the currently supported versions:

• workshop-images/base-environment/opt/kubernetes/bin/kubectl
• workshop-images/base-environment/opt/eduk8s/etc/setup.d/01-kubernetes.sh

(The kubectl-convert plugin and its wrapper were removed in 4.0; branches predating that carry a third copy of the same case statement at opt/kubernetes/bin/kubectl-convert.)

Pattern rules:

• 1.2* and 1.3[012] (or equivalent old versions) → map to the lowest supported version
• One explicit case per supported version (e.g. 1.33, 1.34, 1.35, 1.36)
• Default fallback (*) → the highest supported version

Example for versions 1.33–1.36:

case "$KUBECTL_VERSION" in
1.2*)
    KUBECTL_VERSION=1.33
    ;;
1.3[012])
    KUBECTL_VERSION=1.33
    ;;
1.33)
    KUBECTL_VERSION=1.33
    ;;
1.34)
    KUBECTL_VERSION=1.34
    ;;
1.35)
    KUBECTL_VERSION=1.35
    ;;
1.36)
    KUBECTL_VERSION=1.36
    ;;
*)
    KUBECTL_VERSION=1.36
    ;;
esac

The three files must have identical case statement logic.

client-programs/pkg/constants/kubernetes.go

This map is what educates local cluster create --kubernetes-version uses to pick a kind node image, so the digests must come from the kind release the CLI vendors (sigs.k8s.io/kind in client-programs/go.mod). The node-image set and digests are kind-version-specific — take them from the matching release notes at https://github.com/kubernetes-sigs/kind/releases, not an older kind release.

Update KubernetesVersionToKindImage — add new version entries, remove dropped ones:

var KubernetesVersionToKindImage = map[string]string{
    "1.36": "kindest/node:v1.36.x@sha256:<digest>",
    "1.35": "kindest/node:v1.35.x@sha256:<digest>",
    "1.34": "kindest/node:v1.34.x@sha256:<digest>",
    "1.33": "kindest/node:v1.33.x@sha256:<digest>",
}

const DefaultKubernetesVersion = "1.36"

DefaultKubernetesVersion is the version local cluster create uses when --kubernetes-version is not given. It currently tracks the newest supported version ("1.36"); if you would rather trade recency for stability, the second-newest is a reasonable alternative — just keep it consistent with the code, go.mod, and the release notes.

Whenever the supported set or the vendored kind version changes, also update any code comments that name a specific version or kind release so they still match reality — e.g. the sigs.k8s.io/kind vX.Y.Z note in pkg/constants/kubernetes.go and the example node image in the Ensuring node image (...) comment in pkg/cluster/kindcluster.go.