The ovirt-guest-agent on Ubuntu 16.04 requires a manual fix by touching the log file and providing the proper permissions (e.g. ovirtagent:adm). Otherwise the agent does not start after the installation. Maybe it's also required to deploy a custom logrotate config.
systemctl status ovirt-guest-agent
โ ovirt-guest-agent.service - oVirt Guest Agent
Loaded: loaded (/lib/systemd/system/ovirt-guest-agent.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Sat 2018-06-23 10:36:12 CEST; 12min ago
Process: 2359 ExecStart=/usr/bin/python /usr/share/ovirt-guest-agent/ovirt-guest-agent.py (code=exited, status=1/FAILURE)
Process: 2356 ExecStartPre=/bin/chown ovirtagent:ovirtagent /run/ovirt-guest-agent.pid (code=exited, status=0/SUCCESS)
Process: 2353 ExecStartPre=/bin/touch /run/ovirt-guest-agent.pid (code=exited, status=0/SUCCESS)
Process: 2349 ExecStartPre=/sbin/modprobe virtio_console (code=exited, status=0/SUCCESS)
Main PID: 2359 (code=exited, status=1/FAILURE)
Jun 23 10:36:12 zuse2 python[2359]: File "/usr/lib/python2.7/logging/handlers.py", line 64, in __init__
Jun 23 10:36:12 zuse2 python[2359]: logging.FileHandler.__init__(self, filename, mode, encoding, delay)
Jun 23 10:36:12 zuse2 python[2359]: File "/usr/lib/python2.7/logging/__init__.py", line 913, in __init__
Jun 23 10:36:12 zuse2 python[2359]: StreamHandler.__init__(self, self._open())
Jun 23 10:36:12 zuse2 python[2359]: File "/usr/lib/python2.7/logging/__init__.py", line 943, in _open
Jun 23 10:36:12 zuse2 python[2359]: stream = open(self.baseFilename, self.mode)
Jun 23 10:36:12 zuse2 python[2359]: IOError: [Errno 13] Permission denied: '/var/log/ovirt-guest-agent/ovirt-guest-agent.log'
Jun 23 10:36:12 zuse2 systemd[1]: ovirt-guest-agent.service: Main process exited, code=exited, status=1/FAILURE
Jun 23 10:36:12 zuse2 systemd[1]: ovirt-guest-agent.service: Unit entered failed state.
Jun 23 10:36:12 zuse2 systemd[1]: ovirt-guest-agent.service: Failed with result 'exit-code'.
ovirt-agent to run out-of-the-box.
ovirt-agent does not run and requires manual intervention.