DHCP agent should not load core plugin config file; L3 agent has no
interest in metadata agent configuration file; etc. It's a mistake to
form a single global list of configuration files and pass it into all
processes. Every process should have its own list, that may or may not
have some files in common with other processes.
The only file that is common to all neutron processes is neutron.conf,
and we could in theory keep it into the common list. But I decided at
this point it's better to be explicit about what's loaded into services.
Also the order of arguments is important, and neutron.conf should always
be the first CLI argument, which is hard to achieve by keeping
neutron.conf file in the global list.
Plugins may be interested in loading additional files into neutron
processes. For example, dragonflow needs to load /etc/neutron/dragonflow.ini
into neutron-server. But we should not necessarily load all those files
into all processes, so such extendable lists should be per process.
Besides, neutron_server_config_add_new is already available to use to
append additional configuration files for neutron-server. That's why the
patch completely kills the NEUTRON_CONFIG_ARG variable.
Depends-On: I4bd54a41a45486a5601373f9a9cce74d7686d1aa
Change-Id: Ia3c3862399bba335db5edf9ea70f850fb2638d09
19f4b3faae