Troubleshooting libvirt events errors in minion log

In earlier versions of SUSE Multi-Linux Manager (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 SUSE Multi-Linux Manager versions, this engine is no longer used or supported. However, when you migrate or upgrade SUSE Multi-Linux Manager 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 SUSE Multi-Linux Manager 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.