TestNeutronServer: start function not called (or not logged in the temp file)

[Rodolfo Alonso]

The temp file used to fake the service start, is not initialized. The test is failing in [1].

NOTE: there is an unknown error in the log report [2]. The signal SIG_UNBLOCK does not have a recognized sender.

[1] https://github.com/openstack/neutron/blob/master/neutron/tests/functional/test_server.py#L153-L159
[2] http://logs.openstack.org/12/640812/2/check/neutron-functional/35dc53f/controller/logs/dsvm-functional-logs/neutron.tests.functional.test_server.TestWsgiServer.test_restart_wsgi_on_sighup_multiple_workers.txt.gz#_2019-06-17_20_37_09_085

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.opendev.org/666261

[YAMAMOTO Takashi (yamamoto)]

logstash query:
http://logstash.openstack.org/#dashboard/file/logstash.json?query=build_name%3Aneutron-functional%20AND%20message%3A%5C%22Timed%20out%20waiting%20for%20file%5C%22

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/666261
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=2ffde257cfba3db213edab047cb8f99fd60011a9
Submitter: Zuul
Branch: master

commit 2ffde257cfba3db213edab047cb8f99fd60011a9
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Wed Jun 19 10:45:26 2019 +0000

    Add more debug information TestNeutronServer

    The test cases implemented calling "_test_restart_service_on_sighup",
    mock the service "start" function. This function appends a temporary
    file and this file is read by the main to check the correctness of
    the service and workers executing.

    In case of failure waiting for the file to be created and populated,
    the main function will report now:
    - If the file was not created.
    - The current size of the file, compared to the expected one (the number
      of times the "start" function was called)

    The polling time to check the status of the file was increased to 1
    second.

    Change-Id: I68452408920ad9a1ee7252dd9012f898ddfa7e09
    Related-Bug: #1833279