[BUG] Host certificate file suddenly removed

[Anders Bälter]

Something causes the agent to remove our host cert.

ls /etc/ssh/
...
-rw-r--r--   1 root root    534 Oct 21 12:22 ssh_host_ed25519_key-cert.pub

That file is suddenly gone.

Ubuntu 20.x
waagent 2.8.x

Can send waagent.log privately, but I can't see anything interesting that looks related.

[Patrik Ragnarsson]

This pattern would match the key

WALinuxAgent/azurelinuxagent/common/conf.py

Lines 331 to 332 in 04ded9f

 def get_ssh_key_glob(conf=__conf__): 
     return os.path.join(get_ssh_dir(conf), 'ssh_host_*key*') 

Used in these places https://github.com/Azure/WALinuxAgent/search?q=get_ssh_key_glob

[Anders Bälter]

Deleted here:

WALinuxAgent/azurelinuxagent/pa/provision/default.py

Line 120 in 76f769c

 fileutil.rm_files(conf.get_ssh_key_glob()) 

[Anders Bälter]

But we have Provisioning.RegenerateSshHostKeyPair=n is the config 🤔

[Anders Bälter]

Turns out that cloud-init regenerates to keys for some reason