netapp driver has code incompatible with oslo.config backend drivers

See additional related discussions at https://meetings.opendev.org/meetings/manila/2023/manila.2023-04-06-15.00.log.htm

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/manila/+/880831

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/manila/+/880852

Change abandoned by "Romain Dupont <email address hidden>" on branch: master
Review: https://review.opendev.org/c/openstack/manila/+/880831
Reason: Duplicated

> when working with oslo.config drivers, only sections describing the config sources are in the config file and the rest is external.

Hey Romain,

Is it possible to share a sanitized version of how this configuration looks?

Hi, sure,

At OVHcloud we use a Vault like app to store secrets, so we do retrieve them with oslo.config backend drivers, which means the config file does only contain this:

------
[DEFAULT]
config_source = external_service_config,external_database_config

[external_service_config]
driver = ext_oslo_config_driver
secret_alias = config

[external_database_config]
driver = ext_oslo_config_driver
secret_alias = database
------

We only have backend drivers define in the config, all the manila config and netapp backends are defined in the external secret and our ext_oslo_config_driver class implements the interface to get group and options from this as oslo.config drivers suggest.

The secret could look like something like this:

------
DEFAULT:
....debug: false
....share_manager: "xxx"
....enabled_share_backends: "netappcluster1,netappcluster2"
netappcluster1:
....share_backend_name: "netappcluster1"
....share_driver: "xxx"
....netapp_server_hostname: "xxx"
....netapp_server_port: "443"
....netapp_login: "xxx"
....driver_handles_share_servers: true
netappcluster2:
....share_backend_name: "netappcluster2"
....share_driver: "xxx"
....netapp_server_hostname: "yyy"
....netapp_server_port: "443"
....netapp_login: "yyy"
....driver_handles_share_servers: true
------

What i don't like about the stanza check is that it is not compliant with the fact that backend drivers do not expose the group they have, they only respond to a get on groups/options and returns no value if it does not exist, so there is no mechanism to know if a group exists without requesting it, that's why list_all_sections is outdated.

If you need any more information don't hesitate to contact me