Cannot access instance via SSH today

[Felipe Braga]

Yesterday it worked.

Today:

$ ssh jowsuplementos.com.br (external IP resolved from DNS)
Permission denied (publickey).

... and:

$ gcloud compute ssh jowsuplementos-jessie
No zone specified. Using zone [us-east1-d] for instance: [jowsuplementos-jessie].
Permission denied (publickey).
ERROR: (gcloud.compute.ssh) [/usr/bin/ssh] exited with return code [255].

...and a can't use it via the web console either.

It's a Debian Stretch instance (upgraded from Debian Jessie some weeks ago). There are several GB's in the (only) disk of it - the services that run in it continues to work (besides SSH...)

To me, this lines from the serial console seems related to the issue (because of the info here):

(...)
Aug  1 16:48:01 jowsuplementos-jessie sshd[763]: /etc/ssh/sshd_config line 19: Deprecated option KeyRegenerationInterval
Aug  1 16:48:01 jowsuplementos-jessie sshd[763]: /etc/ssh/sshd_config line 20: Deprecated option ServerKeyBits
Aug  1 16:48:01 jowsuplementos-jessie sshd[763]: /etc/ssh/sshd_config line 31: Deprecated option RSAAuthentication
Aug  1 16:48:01 jowsuplementos-jessie sshd[763]: /etc/ssh/sshd_config line 38: Deprecated option RhostsRSAAuthentication
Aug  1 16:48:01 jowsuplementos-jessie sshd[771]: /etc/ssh/sshd_config line 19: Deprecated option KeyRegenerationInterval
Aug  1 16:48:01 jowsuplementos-jessie sshd[771]: /etc/ssh/sshd_config line 20: Deprecated option ServerKeyBits
Aug  1 16:48:01 jowsuplementos-jessie sshd[771]: /etc/ssh/sshd_config line 31: Deprecated option RSAAuthentication
Aug  1 16:48:01 jowsuplementos-jessie sshd[771]: /etc/ssh/sshd_config line 38: Deprecated option RhostsRSAAuthentication
(...) 

[Rahi (Google Cloud Support)]

Hi Braga,

Did you try removing deprecated configuration lines as mentioned by "Xdg" at the thread you refereed?