Comment 2 for bug 2020216

Reviewed: https://review.opendev.org/c/openstack/charm-mysql-innodb-cluster/+/883698
Committed: https://opendev.org/openstack/charm-mysql-innodb-cluster/commit/2af9b1b4e933751b2ff794a035a6b603067ca0a9
Submitter: "Zuul (22348)"
Branch: master

commit 2af9b1b4e933751b2ff794a035a6b603067ca0a9
Author: Alex Kavanagh <email address hidden>
Date: Fri May 19 18:45:03 2023 +0100

    Fix status during db-router-relation-departed

    The functions get_cluster_instance_mode() and
    get_cluster_status_text() should be able to return None if they can't
    access the relevant status, but it's possible that keys may exist in the
    status and this causes KeyErrors. This patch makes the functions more
    robust such that they return None if the items don't exist. This only
    affects reporting on the status line, rather than functionality in the
    charm.

    Change-Id: Ie63438cc8801224b0608203f7c935c430ef46045
    Closes-Bug: #2020216