Comment 5 for bug 1821782

Reviewed: https://review.opendev.org/713375
Committed: https://git.openstack.org/cgit/openstack/tripleo-common/commit/?id=89d2393ea9fa977946ba34b6b9b3b279f830b64c
Submitter: Zuul
Branch: stable/rocky

commit 89d2393ea9fa977946ba34b6b9b3b279f830b64c
Author: Cédric Jeanneret <email address hidden>
Date: Wed Mar 27 08:58:24 2019 +0100

    Silent file descriptor checks

    In order to avoid spam in journald, we just get the exit code and let
    the checker output the error message.

    Also, correct how we retrieve process in the healthcheck_port and _listen
    functions.
    "ss" doesn't allow to match some processes, like "neutron-l3-agent". We
    therefore use the PID instead, provided by "pgrep".
    The "-d" option of pgrep allow to prepare its output for the "grep -E",
    preventing any need of a loop.

    Change-Id: I1555a9b79c954e646fe9ae35272231c581cea03e
    Closes-Bug: #1821782
    Closes-Bug: #1821856
    (cherry picked from commit 5312bf19c8f820ac65514885aebdc2dc4776d72d)