Permits the container to be restarted

The startup (entrypoint) will exit if the ssh key was already copied to
the root user configuration in a previous start. Making it conditional
will permit one to restart the container with something `docker-compose
restart master-libvirt`. Otherwise, the container needs to be deleted
and restarted.

docker-compose/start.sh

@@ -30,9 +30,11 @@ echo "Crossbar started"
 
 # ssh-key to connect to workers
 if [[ $1 == "master-libvirt" ]]; then
-  mkdir /root/.ssh
-  cp id_ed25519 /root/.ssh
-  cp known_hosts /root/.ssh
+  [[ -d /root/.ssh ]] || {
+    mkdir /root/.ssh
+    cp id_ed25519 /root/.ssh
+    cp known_hosts /root/.ssh
+  }
 fi
 
 # loop for debug