Libvirtd setup instructions unclear

[jmontleon]

Version

N/A

Platform:

libvirt

What happened?

Following the libvirt instructions here led to a broken libvirt install on Fedora 32. They are very unclear:
https://github.com/openshift/installer/blob/master/docs/dev/libvirt/README.md#configure-libvirt-to-accept-tcp-connections

These changes have no effect with systemd sockets:
https://github.com/openshift/installer/blob/master/docs/dev/libvirt/README.md#configure-libvirtdconf

Nor does this:
https://github.com/openshift/installer/blob/master/docs/dev/libvirt/README.md#configure-the-service-runner-to-pass---listen-to-libvirtd

This is sort of accurate but libvirtd must be stopped before trying to start it:

On Fedora 31, you also need to enable and start the libvirtd TCP socket, which is managed by systemd:

sudo systemctl enable libvirtd-tcp.socket
sudo systemctl start libvirtd-tcp.socket

# systemctl start libvirtd
# systemctl start libvirtd-tcp.socket
Job failed. See "journalctl -xe" for details.

# systemctl stop libvirtd
Warning: Stopping libvirtd.service, but it can still be activated by:
  libvirtd-ro.socket
  libvirtd.socket
# systemctl start libvirtd-tcp.socket
# systemctl start libvirtd

I came across https://bugzilla.redhat.com/show_bug.cgi?id=1741403#c4 while trying to figure out what the right steps were and the above appears to be expected:

libvirtd is now using systemd socket activation by default. When systemd activation is used, the --listen parameter no longer has any effect. The demo  /etc/sysconfig/libvirtd file provided by the libvirt RPM contains a warning to this effect.

Instead you need to activate the appropriate socket unit file eg

$  systemctl start libvirtd-tls.socket

or

$ systemctl start libvirtd-tcp.socket

NB, you must start these sockets, *before* libvirtd itself is started.

For the same reason the listen_tcp and listen_tls params in /etc/libvirt/libvirtd.conf also have no effect when systemd activation is used. Again the default config file contains warnings about this.

[cfergeau]

See #3677

[openshift-bot]

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[cfergeau]

The documentation now takes into account libvirtd socket activation. Is this good enough, or does this still need more improvements?

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@openshift-bot: Closing this issue.

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