Troubleshooting libvirt events errors in minion log

In earlier versions of Uyuni (such as SUSE Multi-Linux Manager 4.3), onboarding a client with the Virtualization Host system type deployed an event listener configuration file (/etc/venv-salt-minion/minion.d/libvirt-events.conf or /etc/salt/minion.d/libvirt-events.conf). This configuration enabled the Salt libvirt_events engine to monitor virtualization events on the host. In later Uyuni versions, this engine is no longer used or supported. However, when you migrate or upgrade Uyuni from an earlier version, this configuration file can remain on previously onboarded minions.

When the minion starts, the libvirt_events engine attempts to connect to local libvirt sockets. The minion log file (/var/log/venv-salt-minion.log for Salt Bundle, or /var/log/salt/minion for classic Salt minion) repeatedly records error messages such as:

[salt.loaded.int.engines.libvirt_events:300 ][ERROR   ] Operation not supported: Cannot use direct socket mode if no URI is set. For more information see https://libvirt.org/kbase/failed_connection_after_install.html
libvirt.libvirtError: Operation not supported: Cannot use direct socket mode if no URI is set.

or:

[salt.loaded.int.engines.libvirt_events:300 ][ERROR   ] Failed to connect socket to '/var/run/libvirt/virtnetworkd-sock-ro': No such file or directory
libvirt.libvirtError: Failed to connect socket to '/var/run/libvirt/virtnetworkd-sock-ro': No such file or directory

To resolve this issue, delete the obsolete libvirt-events.conf configuration file from the affected minion and restart the minion service.

Procedure: Removing obsolete libvirt-events configuration on the client

  1. On the affected client, remove the libvirt-events.conf file:

    • For Salt Bundle (venv-salt-minion):

      rm /etc/venv-salt-minion/minion.d/libvirt-events.conf

    • For classic Salt minion:

      rm /etc/salt/minion.d/libvirt-events.conf

  2. Restart the minion service:

    • For Salt Bundle (venv-salt-minion):

      systemctl restart venv-salt-minion

    • For classic Salt minion:

      systemctl restart salt-minion

Alternatively, you can remove the configuration file and restart the minion service across multiple clients by executing Salt commands on the Uyuni Server:

Procedure: Removing obsolete libvirt-events configuration using Salt

  1. Remove the file using the file.remove execution module:

    • For Salt Bundle (venv-salt-minion):

      salt '<target>' file.remove /etc/venv-salt-minion/minion.d/libvirt-events.conf

    • For classic Salt minion:

      salt '<target>' file.remove /etc/salt/minion.d/libvirt-events.conf

  2. Restart the minion service:

    • For Salt Bundle (venv-salt-minion):

      salt '<target>' service.restart venv-salt-minion

    • For classic Salt minion:

      salt '<target>' service.restart salt-minion

After you remove the configuration file and restart the minion service, the minion no longer loads the libvirt_events engine, and the error messages no longer appear in the minion log.