Kubernetes: cannot get path "//.well-known/openid-configuration"

I’ve been playing with using kubernetes service account JWTs to authenticate Pods. To get the cert for checking the JWT signature, I needed to hit the https://kubernetes.default.svc/.well-known/openid-configuration endpoint, however as the URL was coming from a config file it ended up being https://kubernetes.default.svc//.well-known/openid-configuration (mind the double //). This worked well locally where everything runs under the powerful default service account, but when deployed I got an error saying:

  "kind": "Status",
  "apiVersion": "v1",
  "metadata": {

  "status": "Failure",
  "message": "forbidden: User \"system:serviceaccount:my-namespace:my-service-account\" cannot get path \"//.well-known/openid-configuration\"",
  "reason": "Forbidden",
  "details": {

  "code": 403

The solution was to remove the second /, and hitting https://kubernetes.default.svc/.well-known/openid-configuration worked like a charm.

Googleing the error didn’t bring up anything useful, so I’m sharing it here in the hopes of saving others the debugging time.