Export journal files from devstack services

This performs a number of logging collection services

• Export the systemd journal in native format
• For every devstack service, export logs to text in a file named screen-* to maintain legacy compatability when devstack services used to run in a screen session and were logged separately.
• Export a syslog-style file with kernel and sudo messages for legacy compatability.

Writes the output to the logs/ subdirectory of stage_dir.

Role Variables

.. zuul:rolevar:: devstack_base_dir
   :default: /opt/stack

   The devstack base directory. This is used to obtain the
   ``log-start-timestamp.txt``, used to filter the systemd journal.

.. zuul:rolevar:: stage_dir
   :default: {{ ansible_user_dir }}

   The base stage directory.