os_ceilometer role missing functional gate testing of gnocchi storage option

Fix proposed to branch: master
Review: https://review.openstack.org/379634

Reviewed: https://review.openstack.org/379634
Committed: https://git.openstack.org/cgit/openstack/openstack-ansible-os_ceilometer/commit/?id=5ebd74f40f727c69f62f4dfb274dde7766538165
Submitter: Jenkins
Branch: master

commit 5ebd74f40f727c69f62f4dfb274dde7766538165
Author: Travis Truman <email address hidden>
Date: Thu Sep 29 13:56:59 2016 -0400

    Add func_gnocchi scenario gate test

    This gate test omits installation of MongoDB
    and uses gnocchi for all metric storage

    Change-Id: I15fff275b3e5eaecb36a0da01c5aafc824c5a288
    Closes-Bug: #1628952

Apparently the jenkins job name is now too long for tox to be able to run the scenario test: http://logs.openstack.org/33/381133/1/check/gate-openstack-ansible-os_ceilometer-ansible-func_gnocchi-ubuntu-xenial-nv/24c4a97/console.html#_2016-10-03_14_39_11_899453

First attempted solution https://review.openstack.org/#/c/381185/, but I clearly lack a sufficient understanding of how all of the CI stuff maps together.

Role gate scenario is in place but failing as the ceilometer_api is not starting. The api is not starting because the DbHooks class is attempting to get a connection to MongoDB when no mongo install has been done or is in fact required.

Based on feedback from Gordon Chung in #openstack-telemetry - http://eavesdrop.openstack.org/irclogs/%23openstack-telemetry/%23openstack-telemetry.2016-10-04.log.html#t2016-10-04T20:08:57 it sounds like the scenario gate and the role needs further work.

Further work will be:
 * Modify the role to not install Apache or the ceilometer-api upstart/systemd service when Gnocchi is enabled for storage
 * Modify the functional test to not attempt to reach the ceilometer-api when Gnocchi is enabled for storage.

This issue was fixed in the openstack/openstack-ansible-os_ceilometer 15.0.0.0b1 development milestone.

Proper fix for this is blocked by Bug #1624789 and should probably be running the following tempest tests

https://github.com/openstack/ceilometer/blob/master/tox.ini#L28-L36