Not able to access kubernetes api from inside a pod container
Your login request is being sent to the tokenreview endpoint on port 80. I think this is because your kubernetes_host specifies a http URL. The 500 response is because it's not listening on port 80, but on 443 instead (as you can see in your service list output).
Try changing to https when configuring the auth, i.e.
payload.json{ "kubernetes_host": "https://kubernetes", "kubernetes_ca_cert": <k8s service account token>}
Finally I have figured out what went wrong:
my payload.json content was wrong
it should be like this:
{ "kubernetes_host": "https://kubernetes", "kubernetes_ca_cert": <kubectl exec to vault pod and cat /var/run/secrets/kubernetes.io/serviceaccount/ca.crt, now make the cert one line by following this answer: https://stackoverflow.com/a/14580203/2054147>}Now below endpoint is working fine and returning the desire client_token
curl --request POST --data @payload2.json http://127.0.0.1:8200/v1/auth/kubernetes/loginThanks @John for helping me to figure out the initial issue with kubernetes_host.