Need monitoring for installed services for OVN

[Drew Freiberger]

There are no ovn-chassis, ovn-central, north/southdb, nor ovn-controller monitors defined for relations to nrpe-external-master on any OVN charms. This leaves us only with openstack-service-checks testing for active/dead agents.

Please add nagios monitoring to all ovn charms.

[Xav Paice (xavpaice)]

PRs in progress for service checks:

https://review.opendev.org/754631
https://review.opendev.org/754632
https://github.com/openstack-charmers/charm-layer-ovn/pull/23
https://github.com/openstack-charmers/zaza-openstack-tests/pull/433

We could use another round of changes to run various queries and check the results, the above changes simply ensure the services themselves are running according to systemd.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/753948
Committed: https://git.openstack.org/cgit/x/charm-ovn-central/commit/?id=bf00c7c3a368571f6a3fe2aef487e2bf626bed37
Submitter: Zuul
Branch: master

commit bf00c7c3a368571f6a3fe2aef487e2bf626bed37
Author: Xav Paice <email address hidden>
Date: Thu Sep 24 16:56:53 2020 +1200

    Add NRPE checks for services

    Adds the nrpe-external-master layer and checks for services managed by
    this charm.

    func-test-pr: https://github.com/openstack-charmers/zaza-openstack-tests/pull/433

    Change-Id: I8f45a612cf4e6df7618edcd8930f2bb199fa69fd
    Closes-Bug: #1896674

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/754631
Committed: https://git.openstack.org/cgit/x/charm-ovn-chassis/commit/?id=e8efd4606e809988bf91556900a9cbeb3f091256
Submitter: Zuul
Branch: master

commit e8efd4606e809988bf91556900a9cbeb3f091256
Author: Xav Paice <email address hidden>
Date: Mon Sep 28 17:59:00 2020 +1300

    Add NRPE checks for services

    Adds the nrpe-external-master layer and checks for services managed by
    this charm.

    func-test-pr: https://github.com/openstack-charmers/zaza-openstack-tests/pull/433
    Layer PR: https://github.com/openstack-charmers/charm-layer-ovn/pull/23

    Change-Id: I6499c4d92d9c495f92f750061d82d06642c0ccfb
    Closes-Bug: #1896674