Given this cluster:
[Units]
ID WORKLOAD-STATUS JUJU-STATUS VERSION MACHINE PORTS PUBLIC-ADDRESS MESSAGE
consul/0 unknown idle 2.0-beta6 1 53/tcp,8302/tcp,8400/tcp,8500/tcp 146.148.82.194
consul/1 unknown idle 2.0-beta6 2 53/tcp,8302/tcp,8400/tcp,8500/tcp 104.197.156.72
consul/2 unknown idle 2.0-beta6 3 53/tcp,8302/tcp,8400/tcp,8500/tcp 130.211.205.104
swarm/0 active idle 2.0-beta6 4 2376/tcp,3376/tcp 104.154.53.65 Swarm leader running
swarm/1 active idle 2.0-beta6 5 2376/tcp 104.197.176.12 Swarm follower
The swarm author used reactive to leave a "Swarm leader" and "swarm follower" status so it's obvious who is the leader/follower. The consul author did not do that. So we thought that having a charm always leave a message in status would be a good best practice. However, Juju actually knows all the leadership statuses already. So instead of this being a charm specific feature, we feel that Juju should make it obvious which node is a service leader, who is a follower, and so on. Or maybe just mark who the leader is with a * or something.
I like the idea of highlighting the leader, not sure we need to mark followers especially given that anyone not a leader is a follower. Being able to query leadership from status will help with a lot of orchestration integration platforms that need/want to run commands only against a leader.