How to pass feature-gate with k3d (Documentation seems out of date)

[tom-mayer]

Question / Where do you need Help?

Hey,
we have an encrypted harddrive which leads to certain problems when starting Kubernetes clusters (locally or in docker). To avoid that we have to use a feature-gate, the command to start minikube looks like this: minikube start --feature-gates="LocalStorageCapacityIsolation=false"

I'm trying to start k3d now but I cannot figure out how to forward the feature gate. I tried k3d cluster create rancher-test --k3s-arg '--kubelet-arg feature-gates=LocalStorageCapacityIsolation=false@server:0' but that didn't seem to fix the issue.

If I look at the docker container logs I can see Incorrect Usage: flag provided but not defined: -kubelet-arg "feature-gates so probably I'm using something wrong.

In the k3d faq concerning feature gates there are --k3s-agent-arg and --k3s-server-arg mentioned, but those don't seem to exist, at least I get a unknown flag error when I try them.

Scope of your Question

k3d version v5.0.1
k3s version v1.21.5-k3s2 (default)

[tom-mayer]

Using k3d cluster create CLUSTER_NAME -v /dev/mapper:/dev/mapper fixed the issue, seems I also had an BTRFS problem.

[iwilltry42]

Hi @tom-mayer , I'm glad you found the solution already!
For completeness: the k3s-server-arg/k3s-agent-arg flags were renamed to just k3s-arg to support nodefilters.

[BenTheElder]

👋 Kubernetes featuregates are only available until the feature goes GA (or is removed), and then the featuregate is removed and the feature is just on (or removed), LocalStorageCapacityIsolation is going GA in Kubernetes v1.25.0, but I've requested a kubelet option to enable use cases like this and there will be a kubelet option localStorageCapacityIsolation you can set instead (no idea how to do that with k3d, sorry).

kubernetes/kubernetes#111513, kubernetes/enhancements#361