Comment 2 for bug 1940595

"Query machine information from a Juju command", are you saying from a human client (eg `juju machine-...`). Or are you saying from the charm itself? We have talked about updating Provider metadata (like MAAS or AWS tags), so that the provider dashboards have a nicer view (machine-XYZ getting a postgresql tag so you can see what unit/applications are running on which instances).
Is that sufficient for your functional case, or is there a specific tag that you are trying to apply?

Generally we don't really like charms knowing about applications they aren't related to, but if we could understand the use case a bit more it might be reasonable.