Support containerized Vitastor installations

docker/etc/systemd/system/vitastor-osd@.service

@@ -0,0 +1,27 @@
+[Unit]
+Description=Containerized Vitastor object storage daemon osd.%i
+After=network-online.target local-fs.target time-sync.target docker.service vitastor-host.service
+Wants=network-online.target local-fs.target time-sync.target docker.service vitastor-host.service
+PartOf=vitastor.target
+
+[Service]
+LimitNOFILE=1048576
+LimitNPROC=1048576
+LimitMEMLOCK=infinity
+EnvironmentFile=/etc/vitastor/docker.conf
+SyslogIdentifier=vitastor-osd%i
+ExecStart=bash -c 'docker run --rm -i -v /etc/vitastor:/etc/vitastor -v /dev:/dev \
+    $(for i in $(ls /dev/vitastor/osd%i-*); do echo --device $i:$i; done) \
+    --log-driver none --network host --ulimit nofile=1048576 --ulimit memlock=-1 $CONTAINER_OPTIONS --name vitastor-osd%i \
+    vitastor:$VITASTOR_VERSION vitastor-disk exec-osd /dev/vitastor/osd%i-data'
+ExecStartPre=+docker exec vitastor vitastor-disk pre-exec /dev/vitastor/osd%i-data
+ExecStop=docker stop vitastor-etcd%i
+WorkingDirectory=/
+PrivateTmp=false
+TasksMax=infinity
+Restart=always
+StartLimitInterval=0
+RestartSec=10
+
+[Install]
+WantedBy=vitastor.target