No action to create a cephfs user

[Peter Matulis]

I do not see an action to create a CephFS service user. I'm looking for an action that can perform the equivalent of:

$ juju ssh ceph-mon/0 "sudo ceph fs authorize ceph-fs client.test / rw"

Naturally, an MDS server (ceph-fs charm) is a requirement. This should be stated in the action's description.

Typically the generated keyring file for the user (ceph.client.test.keyring in the example above) will be subsequently needed. Is it possible to have the action supply this file's contents in its output?