Comment 8 for bug 1748445

Reviewed: https://review.opencontrail.org/39638
Committed: http://github.com/Juniper/contrail-controller/commit/4334d22e046f6385b0eb5adf0b8d1a8448981793
Submitter: Zuul (<email address hidden>)
Branch: R4.1

commit 4334d22e046f6385b0eb5adf0b8d1a8448981793
Author: Petr Jediný <email address hidden>
Date: Wed Feb 7 16:19:49 2018 +0100

contrail-api systemd template unit support

This requires changes to:
- contrail-status to be able to check workers
- systemd service unit template

Template instance string (part between the "@" character and the
suffix) should be a single digit and it works as worker id.

Warning: using multiple digit number as template instance string in
current setup would lead to "listening" on ports higher than 65536
and it would not work.

Other changes to contrail-api.service files:
- adding /var/lib/contrail to RW Directories to allow interaction
with `keystone-signing` directory
- RestartSec=3s: by default systemd will stop restarting service if it
fails to restart more than five times in ten seconds. To avoid This
rate limit we increase the time between restart to 3s from 100ms.

Closes-Bug: #1748445

Change-Id: If203039f2bec147fe1823fe0b5e8125970f43925
(cherry picked from commit 98b3f5f46891ecc311e01c5f26b8d27852701533)