Simulate a remote/standalone g-api worker

In order to be able to test glance's distributed import function,
we need to have multiple workers in an arrangement like they
would be if one was on another host (potentially at another site).
This extra worker must be separate from the default image service
in order to repeatedly hit one and then the other to test cross-
service interactions.

This allows you to enable_service g-api-r, which will clone the main
g-api service, modify it to run on a different port, and start it.
The service will be registered in the catalog as image_remote.

Depends-On: https://review.opendev.org/c/openstack/glance/+/769976
Change-Id: I0e2bb5412701d515153c023873addb9d7abdb8a4
2 files changed