Return the exception traceback from the daemon execution

[Rodolfo Alonso]

In case of having an exception in the daemon when executing an elevated method, return the traceback.

The goal of this LP is to be able to print, in the called (client) logs the exception occurred in the daemon while executing the elevated method. For example, I implemented a very quick (and intrusive) patch [1] to debug some issues in functional tests. In these tests we don't capture the privsep daemon logs and it was necessary to use [1] to find where the error was happening.

This feature would be configurable and disabled by default.

A client with the new code can communicate to a daemon running the old code. That must be considered in the implementation.

[1]https://review.opendev.org/c/openstack/oslo.privsep/+/943237

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/oslo.privsep/+/943237
Committed: https://opendev.org/openstack/oslo.privsep/commit/cc5981a43631a049448f9104e4da0d9025e64b7b
Submitter: "Zuul (22348)"
Branch: master

commit cc5981a43631a049448f9104e4da0d9025e64b7b
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Sun Mar 2 11:19:20 2025 +0000

    Add daemon traceback to client logger

    A new configuration flag is defined: "log_daemon_traceback", disabled
    by default. If enabled, the exception traceback happened in the daemon
    will be logger as warning message in the client logger. This could be
    helpful in some CI jobs (functional tests), where the privsep logs are
    not stored.

    Closes-Bug: #2101025
    Change-Id: I34fd47d4cb3aa303fad19203bdedffdb09fbac4b

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/oslo.privsep 3.7.0 Flamingo release.