Comment 2 for bug 2036890

Reviewed: https://review.opendev.org/c/openstack/charm-heat-k8s/+/897663
Committed: https://opendev.org/openstack/charm-heat-k8s/commit/0459106b3c1ac573286898f8aefc0280f0bf4358
Submitter: "Zuul (22348)"
Branch: main

commit 0459106b3c1ac573286898f8aefc0280f0bf4358
Author: Hemanth Nakkina <email address hidden>
Date: Mon Oct 9 16:37:03 2023 +0530

    Share auth encryption key over relation

    Currently the Auth encryption key for heat-api
    and heat-api-cfn deployed via charm-heat-k8s
    charm instances are different and so causes
    issues when heat-engine from heat-api-cfn handles
    request for heat-api. The heat-engines of both
    heat-api and heat-api-cfn are used for handling
    both heat-api and heat-api-cfn stacks as the AMQP
    topic is same and not configurable.

    Add a new interface heat-shared-config to share
    the auth encryption key between heat-api and
    heat-api-cfn.
    heat-api update the relation data with auth
    encryption key once the key is generated or
    any new relations are connected via heat-shared-config.
    Save the auth encryption key as juju secret
    instead of plain text and grant access to
    peer and units connected via heat-shared-interface.

    Closes-Bug: #2036890
    Change-Id: I2ec7f03b5c64d87585141e15b20b01172b14ecc4