Comment 2 for bug 1940495

Reviewed: https://review.opendev.org/c/openstack/charm-rabbitmq-server/+/805109
Committed: https://opendev.org/openstack/charm-rabbitmq-server/commit/fd8d018babb16de3ea54f9c99bdd4a9c572695ea
Submitter: "Zuul (22348)"
Branch: master

commit fd8d018babb16de3ea54f9c99bdd4a9c572695ea
Author: Billy Olsen <email address hidden>
Date: Wed Aug 18 20:48:46 2021 -0700

    Move cron max file age calculation to rabbit_utils

    The check_rabbitmq_queues nrpe check accesses the cron file created
    for running collect stats job. This is done in order to determine if
    the stats are too old and an alert should be raised. The nagios user
    does not have access to read the cron job when running in a hardened
    environment where /etc/cron.d is not readable.

    This change refactors this logic to move the calculation of maximum
    age for a stats file from the check_rabbitmq_queues script and into
    the rabbit_utils code where it is generating the nrpe configuration.
    A new (optional) parameter is added to the check_rabbitmq_queues
    script to accept the maximum age in seconds a file can last be
    modified.

    This change also removes the trusty support in hooks/install and
    hooks/upgrade-charm as the rabbit_utils.py file needs to import a
    dependency which is installed by the scripts. It is cleaned up to make
    sure the croniter package is always installed on install or upgrade.

    Change-Id: If948fc921ee0b63682946c7cc879ac50e971e588
    Closes-Bug: #1940495
    Co-authored-by: Aurelien Lourot <email address hidden>