Support containerized Vitastor installations

docker/etc/systemd/system/vitastor-host.service

@@ -0,0 +1,23 @@
+[Unit]
+Description=Empty container for running Vitastor commands
+After=network-online.target local-fs.target time-sync.target docker.service
+Wants=network-online.target local-fs.target time-sync.target docker.service
+PartOf=vitastor.target
+
+[Service]
+Restart=always
+EnvironmentFile=/etc/vitastor/docker.conf
+ExecStart=bash -c 'docker run --rm -i -v /etc/vitastor:/etc/vitastor -v /dev:/dev \
+    --privileged --log-driver none --network host --name vitastor vitastor:$VITASTOR_VERSION \
+    sleep.sh'
+ExecStartPost=udevadm trigger
+ExecStop=docker stop vitastor
+WorkingDirectory=/
+PrivateTmp=false
+TasksMax=infinity
+Restart=always
+StartLimitInterval=0
+RestartSec=10
+
+[Install]
+WantedBy=multi-user.target