Match Teleport version in helm command to Teleport proxy version

[peteroneilljr]

What would you like Teleport to do?

When creating a new Kubernetes token via the command line, the provided helm install command currently installs the latest version of Teleport by default. However, this can cause compatibility issues if the latest Teleport version is ahead of the Cloud Tenant version. For example, my Cloud Tenant is running version 16.4.10, while the latest Teleport version is 17, leading to a mismatch that prevents the agent from connecting to the cluster.

It would be helpful if the helm install command included the --version flag prefilled with the current proxy version to ensure compatibility.

tctl tokens add --type=kube
The invite token: cadd01e292c015af38fa3b59d8a1e57
This token will expire in 30 minutes.

To use with Helm installation, follow these steps:

# Retrieve the Teleport Helm charts
helm repo add teleport https://charts.releases.teleport.dev
# Refresh the Helm charts
helm repo update

> helm install teleport-agent teleport/teleport-kube-agent \
  --set kubeClusterName=cluster `# Change kubeClusterName to your preferred name.` \
  --set roles="kube\,app\,discovery" \
  --set proxyAddr=peter.teleport.sh:443 \
  --set authToken=cadd01e292c015af38fa3b59d8a1e57 \
  --create-namespace \
  --namespace=teleport-agent \
  --version=${current_proxy_version} ## Add this line

What problem does this solve?

This change eliminates confusion for users whose agents fail to come online due to a version mismatch between the installed agent and the cluster proxy.

If a workaround exists, please include it.

The current workaround is to manually determine the cluster's version and add the --version flag to the Helm command. However, this requires extra effort and can be easily overlooked, especially by new users.