Paired with the add path in add_telegraf_to_minion: when a minion is
removed, drop its entry from the aggregate postgres pillar and drop the
matching so_telegraf_<safe> role from the database. Without this, stale
entries and DB roles accumulate over time.
Makes rotate-password and compromise-recovery both a clean delete+add:
so-minion -o=delete -m=<id>
so-minion -o=add -m=<id>
The first call drops the role and clears the aggregate pillar; the
second generates a brand-new password.
The cleanup is best-effort — if so-postgres isn't running or the DROP
ROLE fails (e.g., the role owns unexpected objects), we log a warning
and continue so the minion delete itself never gets blocked by postgres
state. Admins can mop up stray roles manually if that happens.
Mike Reeves
dbf4fb66a4