[[!comment format=mdwn username="joey" subject="""comment 5""" date="2019-07-21T15:18:51Z" content=""" This seems like a reasonable change to make, although I am not sure I understand how you'd practially use it. But as far as how to implement it, you merely need to make an IsInfo instance for Host (or for [Host]) and then each of the container properties can add the Host of their container to the Info. Hmm, actually, this info is already provided in another way. In Propellor.Types.Chroot there is a ChrootInfo that builds up a map from chroot location to Host, and that gets added to the Info of the host where the chroot is used. As well as being used for regular chroots, the systemd containers are based on a chroot and so also use and provide it. Docker does not currently use it though. It has a separate DockerInfo that also happens to include the Host corresponding to the docker container. Anyway, I guess I'm a little bit unclear on what your original problem was, it might help if you could restate it in more detail to see if this would really help with it. """]]