bundles/docker-engine: support different user, arbitrary mapped volumes, custom command

bundles/docker-engine/files/docker-wrapper

@@ -12,8 +12,8 @@ then
     exit 1
 fi
 
-PUID="$(id -u "docker-${name}")"
-PGID="$(id -g "docker-${name}")"
+PUID="$(id -u "${user}")"
+PGID="$(id -g "${user}")"
 
 if [ "$ACTION" == "start" ]
 then
@@ -32,10 +32,19 @@ then
         --publish "127.0.0.1:${host_port}:${container_port}" \
 % endfor
 % for host_path, container_path in sorted(volumes.items()):
+%  if host_path.startswith('/'):
+        --volume "${host_path}:${container_path}" \
+%  else:
         --volume "/var/opt/docker-engine/${name}/${host_path}:${container_path}" \
+%  endif
 % endfor
         --restart unless-stopped \
+% if command:
+        "${image}" \
+        "${command}"
+% else:
         "${image}"
+% endif
 
 elif [ "$ACTION" == "stop" ]
 then