Comment 2 for bug 1947030

so in the output that you mention you can say that:
application:
  ceph-mon:
  ...
  relations:
    client: <- endpoint
      - cinder-ceph
...
  cinder-ceph:
    relations:
      ceph:
      - ceph-mon

So you can see that ceph-mon on the client endpoint is related to cinder-ceph, and cinder-ceph on the ceph endpoint is related to cinder-mon.

I agree that it isn't explicitly clear that those are both ends of the link, but certainly in any case where a is related to b only a single time, you can see which endpoint in a you find b, and which endpoint in b you find a.

Interestingly that information is more obvious in 'show-unit' but not in 'show-application':
```
$ juju show-unit dummy-sink/0
dummy-sink/0:
  machine: "0"
  opened-ports: []
  public-address: 10.5.24.108
  charm: local:xenial/dummy-sink-0
  leader: true
  relation-info:
  - endpoint: source
    related-endpoint: sink
...
```
(show application doesn't list any relations)

We could change 'juju status --format=yaml' to have:
```
ceph-mon:
  relations:
    client:
      - cinder-ceph:ceph
```

I would worry a bit that we are changing the structure of the yaml output which we generally try to preserve compatibility. (we have added fields, but rarely do we change the content of a field)