Issue accessing kubernetes apis from a pod in azure environment

0
votes

I'm running kubernetes cluster in azure environment and I want to access kubernetes service apis from inside a pod container. But I cannot connect to https://kubernetes/ from inside a pod.

kubectl get services
NAME               CLUSTER_IP      EXTERNAL_IP   PORT(S)
kubernetes         10.16.0.1       <none>        443/TCP

Even trying 

curl -v --cacert /var/run/kubernetes/apiserver.crt https://10.16.0.1:443/api/v1/namespaces/default/pods

results in

  • Trying 10.16.0.1...
  • Connected to 10.16.0.1 (10.16.0.1) port 443 (#0)
  • ALPN, offering http/1.1
  • Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
  • successfully set certificate verify locations:
  • CAfile: /var/run/kubernetes/apiserver.crt CApath: /etc/ssl/certs
  • TLSv1.2 (OUT), TLS header, Certificate Status (22):
  • TLSv1.2 (OUT), TLS handshake, Client hello (1):
  • Unknown SSL protocol error in connection to 10.16.0.1:443
  • Closing connection 0 curl: (35) Unknown SSL protocol error in connection to 10.16.0.1:443
1
azurekubernetes
Does it work if you run curl -k ... (e.g. is it just the SSL verification that is failing)? – Robert Bailey
Already tried with -k option. same issue. – Phagun Baya
Debugged this issue further. In gce environment from within a pod I can run curl -v -k https://kubernetes but in azure environment kubernetes is not getting resolved to corresponding IP address. – Phagun Baya
Can you check to see if the kubernetes service has any endpoints registered (run kubectl get endpoints)? – Robert Bailey
Yes endpoint is assigned but port is 6443 – Phagun Baya

1 Answers

1
votes

Following fix worked:

  1. Changed line https://github.com/kubernetes/kubernetes/blob/v1.2.0/docs/getting-started-guides/coreos/azure/cloud_config_templates/kubernetes-cluster-main-nodes-template.yml#L218 to have --bind-address=0.0.0.0 option also.
  2. Created kubernetes cluster
  3. Made kubernetes api port accessible from outside.

You can access kubernetes api using host as node's ip address and the port.