Need a way to specify UID that owns a volume

[marsbard]

Sometimes you need a certain UID to own a volume, for example jenkins will not start unless you do this first:
$ sudo chown -R 1000 /var/lib/grua/volumes/artif/jenkins/home/

So we could have something like - if volumes arg prefixed by uid, chown before running...:

  volumes:
    - 1000:home:/var/jenkins_home

[marsbard]

Or maybe if there are 3 args split by ":"?

Or perhaps use a different separator?

  ...
  volumes
    - 1000|home:/var/jenkins_home
    - martian|foo:/var/foo