google-guest-agent logs error on Ubuntu 24.04 saying it failed to restart sshd.service after successfully restarting ssh.service

[Ankush-Pathak]

google-guest-agent.service reports the following error on Ubuntu 24.04 (noble)

ERROR oslogin.go:163 Error reloading service: Failed to reload-or-restart sshd.service: Unit sshd.service not found..

This error can be slightly misleading, as google-guest-agent.service still restarts ssh.service successfully before attempting to restart sshd.service. See code.

sshd.service is not loaded on Ubuntu 24.04 due to bug LP #2087949. sshd.service is just an alias to ssh.service. So technically, sshd.service exists but is not loaded.

$ systemctl list-units --all sshd.service
  UNIT         LOAD      ACTIVE   SUB  DESCRIPTION 
● sshd.service not-found inactive dead sshd.service

Legend: LOAD   → Reflects whether the unit definition was properly loaded.
        ACTIVE → The high-level unit activation state, i.e. generalization of SUB.
        SUB    → The low-level unit activation state, values depend on unit type.

1 loaded units listed.
To show all installed unit files use 'systemctl list-unit-files'.

Given google-guest-agent.service tries to skip restarting services that do not exist, perhaps it should also skip restarting services that failed to load as a way to avoid logging the error mentioned above. Or maybe log an error only if it fails to restart both ssh.service and sshd.service in this case.