Authentication for sentinels was implemented in v1.1.5 (commit 2e76410)
but ended up being bugged (see ISSUE #658). This is now postponed as it
requires a more thorough investigation.
Password-based authentication for sentinels has been added in Redis 5.
Predis was actively ignoring any "password" parameter for sentinels when
creating connections to them to avoid issues when this parameter is set
in the default "parameters" array passed via client options, as they are
applied to **every** connection created by Predis (see #346).
We need to find a better way to specify a common password for sentinels
to be handled in a different way than the ones for Redis nodes. For now
each sentinel node protected by password must have an explicit password
set in its parameters list even if this password, by design, is the same
for all sentinels. Since we cannot use default "parameters" as explained
above but we still need to pass a common value for all sentinels an idea
could be using a dedicated client option like we did with "service", but
we will see later.
In this commit we also explicitly reset any "username" parameter as it
would trigger an `AUTH $username $password` but sentinels do not support
ACL authentication.
Fixes#594.
Daniele Alessandri
Pascal Hofmann