- images manifest push/pull are routed through the django server
- all other endpoints are routed directly to the registry


On client-side the registry url is the is the same as the allgo server.
The backend registry location is configured by the
ALLGO_REGISTRY_PRIVATE_URL which is set to "http://{ENV}-registry"
by default (i.e. 'http://dev-registry' in dev)


Because the registry URL is configured at runtime (by the env
var), the nginx config can no longer be static.
/etc/nginc/conf.d/allgo.conf is generated at runtime
 (after loading the django config)