[libvirt] [PATCH] libvirtd: Explicit dependency on systemd-machined

[Michal Koutný]

The libvirtd daemon uses systemd-machined D-Bus API when manipulating
domains. The systemd-machined is D-Bus activated on demand.

However, during system shutdown systemd-machined is stopped concurrently
with libvirtd and virsh users also doing their final cleanup may
transitively fail due to unavailability of systemd-machined. Example
error message

> libvirtd[1390]: 2017-12-20 18:55:56.182+0000: 32700: error : virSystemdTerminateMachine:503 : Refusing activation, D-Bus is shutting down.

To circumvent this we need to explicitly specify both ordering and
requirement dependency (to avoid late D-Bus activation) on
systemd-machined. See [1] for the dependency debate.

[1] https://lists.freedesktop.org/archives/systemd-devel/2018-January/040095.html
---

The Wants= dependency is for the case when systemd-machined wasn't started
neither D-Bus activated anytime before the shutdown transaction. AFAICS this is
very unlikely so for the sake of lazy activation, the Wants= hunk can be
dropped.

 daemon/libvirtd.service.in | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/daemon/libvirtd.service.in b/daemon/libvirtd.service.in
index c189f5e65..769702ea7 100644
--- a/daemon/libvirtd.service.in
+++ b/daemon/libvirtd.service.in
@@ -7,6 +7,7 @@
 Description=Virtualization daemon
 Requires=virtlogd.socket
 Requires=virtlockd.socket
+Wants=systemd-machined.service
 Before=libvirt-guests.service
 After=network.target
 After=dbus.service
@@ -14,6 +15,7 @@ After=iscsid.service
 After=apparmor.service
 After=local-fs.target
 After=remote-fs.target
+After=systemd-machined.service
 Documentation=man:libvirtd(8)
 Documentation=https://libvirt.org
 
-- 
2.13.6