Comment 4 for bug 2033306

Reviewed: https://review.opendev.org/c/openstack/charm-mysql-innodb-cluster/+/892989
Committed: https://opendev.org/openstack/charm-mysql-innodb-cluster/commit/83bc7b36aeb038b7ce2d16ec023fa971bfc091f1
Submitter: "Zuul (22348)"
Branch: master

commit 83bc7b36aeb038b7ce2d16ec023fa971bfc091f1
Author: Felipe Reyes <email address hidden>
Date: Mon Aug 28 20:58:47 2023 -0400

    Delay prom_exporter user creation until password is available.

    There are situations where the create_local_prometheus_exporter_user()
    handler could be executed in a follower unit before the leader units
    gets the chance to generate a password for the prom_exporter user and
    store it in the leader databag, this has the consequence that the
    prom_exporter user is created with the password 'None' (string
    representation of the `None` value), this leads to the problem that the
    mysql_exporter daemon can't connect to mysqld.

    This patch checks that the password is available, if it isn't, then bail
    out and let subsequent executions to re-evaluate this condition.

    Closes-Bug: #2033306
    Change-Id: I58fc489fd4cc4e06b11c293f63e73bd0ab18897f