enable_new_services option can not be configured per host

[Yuki Nishiwaki]

Description
===========

The enable_new_services option for nova-compute can not be configured per host. Even if I updated nova.conf for "nova-compute", that option value is always ignores and somehow Nova seems expect the operator to configure enable_new_services option in nova-conductor although enable_new_service option is for nova-compute related configuration.

This behavior is weird to me and I was the person who mis-understood I can configure enable_new_services in nova.conf for nova-compute.

So I would strongly suggest to change that behavior or help document so as to mention where enable_new_services should be configured.

I already wrote the patch for nova to check enable_new_services option in nova-compute technically Service module which is used by all nova related daemon.

Steps to reproduce
==================
Just deployed OpenStack somehow

* Stop nova-compute on HOST1
* Change enable_new_services configuration from True to False in nova-compute on HOST1
* nova-compute service on HOST1 is deleted by CLI
* nova-compute is started on HOST1

Expected result
===============
* nova-compute service on HOST1 is registered as disabled service

Actual result
=============
* nova-compute service on HOST1 is registered as enable service

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/540962

[Yuki Nishiwaki (uckey-1067)]

Updates:
I just confirmed, The master branch as of 2 February have changed the document(help) and new document explicitly mentioned "enable_new_services" is for only nova-compute.

So now this problem area has been narrowed into the problem that we can not configure "enable_new_services" per host.