Tip: kube-apiserver can't start after adding a parameter

 Symptom:

We add a new oidc parameter for kube-apiserver to integrate with openID Dex.

The parameter is  --oidc-groups-prefix=oidc:

After that, kubelet can't start kube-apiserver static pod, and no obvious error reported

Solution:

The issue is to ":"  which is special character. It prevents kubelet to parse the parameter.

The right way is to quote it.  "--oidc-groups-prefix=oidc:" See more details in this github thread

Error: invalid bearer token, oidc: verify token: oidc: expected audience

Symptom:

After we implemented dex + github via link. With example-app,we are able to get ID-token via http://127.0.0.1:5555/
With ID-token, we construct kubeconfig, but when we access k8s cluster we hit error:

error: You must be logged in to the server (Unauthorized)

In kube api server logs, we see error:

invalid bearer token, oidc: verify token: oidc: expected audience \"123456\" got [\"example-app\"]]"

 Triage:

Check payload and verify JWT ID-token on https://jwt.io

Check dex container logs 

Find similar issues in github link1 link2

Solution:

It turns out the client-id is not matched. 

The client-id set on K8S API server (--oidc-client-id) link   needs to match the client-id in example-app.

In above example, “123456” is the one I set on K8S API server, while client-id is “example-app”  in the example-app which caused the problem