[Feature] Allow using internal interface for all services

[engel75]

Currently even is identity_interface: internal is used the exporter will use the public endpoints to gather metrics. Could you please enable the exporter to honor interface: internal. Like:

clouds:
 'os1':
   region_name: "reg1"
   identity_api_version: 3
   identity_interface: internal
   interface: internal
   auth:
     username: "admin"
     password: "somesupersecret"
     project_name: "admin"
     project_domain_name: 'Default'
     user_domain_name: 'Default'
     auth_url: http:https://keystone.service.dev.i.exampe.org:5000/v3
     verify: false

[alexeymyltsev]

Hi @engel75 , as I see for this moment Endpoint type can be set only with flag --endpoint-type=.

• If we will add endpoint type from config it mean that we should rewrite flag value, but from my point of view flag should have priority over config.
• If we will change behaviour and flag will not have default value it is mean that we break compatibility with previous version of exporter.