I have an instance of Google Cloud Platform Compute running CentOS 7. It works great, where I can use it with the SSH web interface without any problems. Recently I switched to "OS Login" and configured it to be able to use RSA keys to authenticate for SSH (using my computer's terminal program, rather than using a browser terminal window). It also worked well. (For some reason, GCP created a second user account on the CentOS system for me, but that doesn't really matter to me.)
The other day, I ran
sudo dnf upgrade to update the system. The update is complete and I ran
sudo shutdown -r now to restart.
uname -a give me now
Linux centos7 3.10.0-1062.12.1.el7.x86_64 #1 SMP Tue Feb 4 23:02:59 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux.
All of a sudden, I can't SSH into the system using OS Login. (Today I disabled the connection to the operating system and the old method works.) Here is what I encountered:
– The SSH key that I was using did not work ("Authorization refused"). I have verified that it is the correct one and I know that it has not expired.
– I could not use the SSH mechanism based on a GCP browser as I did before. (I'm not sure, but it may be because I activated the connection to the operating system.) If I try to use it, a message contextual is displayed (one after the other):
"Connection … Transfer of SSH keys to the virtual machine."
"Connection … Establishing a connection to the SSH server."
"Unable to connect, retry (1/3) …"
"The connection to the SSH server has expired."
"The release of the VM serial console can provide details to help resolve connection issues. See our help document for other possible causes of this issue." (The part "(1/3)" becomes "(2/3)" then "(3/3)" after a few seconds.)
The link to the help document does not solve the problem. (https://cloud.google.com/compute/docs/ssh-in-browser#couldnotconnecterror)
– I am not running a custom operating system image.
– I know the disc is not full.
– I didn't do anything funny with the permissions of the SSH key files.
The instance seemed to respond to start / stop commands from the web interface, so I restarted it, which didn't change anything.
Thinking back to the pop-up message, I checked the output from the serial console. You can see a copy on pastebin: https://pastebin.com/p8yjGazG
The only thing I can see that could be a problem is a message about not being able to release an IPv6 lease, but I am not an expert.
dnf upgrade break something? Am I just missing something obvious? (Is a Google employee playing a prank?)
If someone could give a glimpse of this problem, it would be great!