db-router incomplete when relation to mysql-innodb-cluster is removed and readded

[Liam Young]

When the relation to mysql-innodb-cluster is removed and then added back, mysql-router reports:

"'db-router' incomplete, Waiting for proxied DB creation from cluster"

This appears to be because the prefixes key is not cleared from the local db when the relation is removed. When the relation is added back the charm looks for a password from mysql-innodb-cluster relating to each of the prefixes it knows about *1. However db-router has not sent a request for the MRUP prefix yet but the interface is waiting on a response.

Removing the relation, deleting the prefix key from the db and adding the relation back fixes the issue:

delete from kv where key like '%prefix%';

*1 https://github.com/openstack/charm-interface-mysql-router/blob/master/requires.py#L133

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/charm-interface-mysql-router/+/841581

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/charm-interface-mysql-router/+/841581
Committed: https://opendev.org/openstack/charm-interface-mysql-router/commit/77dc778e6060a9bcdc49490c3e782b2204ba7454
Submitter: "Zuul (22348)"
Branch: master

commit 77dc778e6060a9bcdc49490c3e782b2204ba7454
Author: Liam Young <email address hidden>
Date: Thu May 12 12:11:05 2022 +0000

    Wipe 'prefixes' key on relation departed

    The prefix key is used to track requests that have been proxied
    to mysql-innodb-cluster. When a request for a username and password
    is made the prefix used is stored locally in a list *1. This list
    of prefixes is also used to check that requests are complete *2
    However the list presists after a relation is removed. If
    the relation is added back the charm reads the old list of
    prefixes and will not raise the db-router.available flag
    because it thinks there is an oustanding request *3.

    *1 https://opendev.org/openstack/charm-interface-mysql-router/src/branch/master/requires.py#L61
    *2 https://opendev.org/openstack/charm-interface-mysql-router/src/branch/master/requires.py#L151
    *3 https://opendev.org/openstack/charm-interface-mysql-router/src/branch/master/requires.py#L20

    Closes-Bug: #1972883
    Change-Id: I8ce022a44db37ab83c03442c5f97a843521286d2

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/jammy
Review: https://review.opendev.org/c/openstack/charm-mysql-router/+/914571

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/21.10
Review: https://review.opendev.org/c/openstack/charm-mysql-router/+/914572

[OpenStack Infra (hudson-openstack)]

Change abandoned by "Seyeong Kim <email address hidden>" on branch: stable/21.10
Review: https://review.opendev.org/c/openstack/charm-mysql-router/+/914572

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/charm-mysql-router/+/914571
Committed: https://opendev.org/openstack/charm-mysql-router/commit/740cae9841bc34ae9ede97132e966ad6853a52bf
Submitter: "Zuul (22348)"
Branch: stable/jammy

commit 740cae9841bc34ae9ede97132e966ad6853a52bf
Author: Seyeong Kim <email address hidden>
Date: Thu Mar 28 12:20:54 2024 +0900

    Update interface-mysql-router

    fix prefix issue when remove&add relation

    Closes-Bug: #1972883
    Change-Id: Ica6e5af2dc2d6adf0d6e6dc4be0ad4a6eab7b4d0