SSH fails with Permission denied error in RHOCP 4

Issue

• Permission denied when doing SSH to any random node in the cluster.

$ ssh -i <key-path> worker-0.example.com
Permission denied (publickey,gssapi-keyex,gssapi-with-mic).

• However, the debug method to connect with the nodes is working perfectly.

$ oc debug node/worker-0.example.com
Starting pod/worker-0.example.com-debug ...
To use host binaries, run `chroot /host`
Pod IP: xx.xx.xx.xx
If you don't see a command prompt, try pressing enter.
sh-4.4#