update-status hook sometimes errors out without a trace

[Aurelien Lourot]

In this CI run [0] an hacluster unit ended up in this state:

hacluster/1 error idle [...] hook failed: "update-status"

And the logs of that unit didn't contain any error. set_unit_status() [1] must have raised an exception.

We should print the stacktrace of such exceptions in order to understand this kind of issues.

0: https://openstack-ci-reports.ubuntu.com/artifacts/test_charm_pipeline_func_full/openstack/charm-percona-cluster/726165/1/5600/index.html
1: https://github.com/openstack/charm-hacluster/blob/master/hooks/hooks.py#L663

[Aurelien Lourot (aurelien-lourot)]

https://review.opendev.org/#/c/727212

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/727212
Committed: https://git.openstack.org/cgit/openstack/charm-hacluster/commit/?id=c30f8a8e19bc195e0686fbdc7fcf940fe2fa8377
Submitter: Zuul
Branch: master

commit c30f8a8e19bc195e0686fbdc7fcf940fe2fa8377
Author: Aurelien Lourot <email address hidden>
Date: Tue May 12 14:17:23 2020 +0200

    Trace failures of set_unit_status()

    Closes-Bug: #1878221
    Change-Id: I9a741d51fb2bab7be12fd0496af6a18bbddd1709