Libvirt: gracefully shutdown libvirt process on container stop.

This PS gracefully shutdowns the libvirt process on pod termiantion.

Change-Id: I4f7f2cac2e2a8586f5c40ac1ad556be74e29459a
Signed-off-by: Pete Birley <pete@port.direct>

libvirt/templates/daemonset-libvirt.yaml

@@ -121,6 +121,14 @@ spec:
           {{ end }}
           command:
             - /tmp/libvirt.sh
+          lifecycle:
+            preStop:
+              exec:
+                command:
+                  - bash
+                  - -c
+                  - |-
+                    kill $(cat /var/run/libvirtd.pid)
           volumeMounts:
             - name: libvirt-bin
               mountPath: /tmp/libvirt.sh