Glances: Cinder backend support

[Lukas M]

Kolla-ansible does not implement support for Cinder backend in Glance.

Related changes for glance-api.conf
```
[DEFAULT]
enabled_backends = cinder:cinder
#cinder_catalog_info = volumev3:cinderv3:internalURL

[glance_store]
default_backend = cinder

[cinder]
cinder_catalog_info = volumev3:cinderv3:internalURL
cinder_volume_type = test
cinder_store_user_name = cinder
cinder_store_password = XXXX
cinder_os_region_name = RegionOne
cinder_store_auth_address = http://172.17.0.11:5000
cinder_store_project_domain_name = Default
cinder_store_project_name = service
cinder_ca_certificates_file = /etc/ssl/certs/ca-certificates.crt

[privsep_entrypoint]
helper_command = sudo glance-rootwrap /etc/glance/rootwrap.conf privsep-helper --config-file /etc/glance/glance-api.conf
```

Also Glance image must contain nvme-cli, systemctl.

Still can not connect to iscsi portal.
```
2023-02-14 10:52:50.138 799 DEBUG oslo.privsep.daemon [-] privsep: Exception during request[674c325f-89f3-4fa5-93f8-fab6c6fb3ddd]: Unexpected error while running command.
Command: iscsiadm -m node -T iqn.2010-10.org.openstack:volume-8092f9fe-8801-4b6a-bf9e-41248c929dcb -p 172.17.0.20:3260 --login
Exit code: 20
Stdout: 'Logging in to [iface: default, target: iqn.2010-10.org.openstack:volume-8092f9fe-8801-4b6a-bf9e-41248c929dcb, portal: 172.17.0.20,3260]\n'
Stderr: 'iscsiadm: can not connect to iSCSI daemon (111)!\niscsiadm: Could not login to [iface: default, target: iqn.2010-10.org.openstack:volume-8092f9fe-8801-4b6a-bf9e-41248c929dcb, portal: 172.17.0.20,3260].\niscsiadm: initiator reported error (20 - could not connect to iscsid)\niscsiadm: Could not log
into all portals\n' _process_cmd /var/lib/kolla/venv/lib/python3.10/site-packages/oslo_privsep/daemon.py:479
Traceback (most recent call last):
  File "/var/lib/kolla/venv/lib/python3.10/site-packages/oslo_privsep/daemon.py", line 476, in _process_cmd
    ret = func(*f_args, **f_kwargs)
  File "/var/lib/kolla/venv/lib/python3.10/site-packages/oslo_privsep/priv_context.py", line 274, in _wrap
    return func(*args, **kwargs)
  File "/var/lib/kolla/venv/lib/python3.10/site-packages/os_brick/privileged/rootwrap.py", line 197, in execute_root
    return custom_execute(*cmd, shell=False, run_as_root=False, **kwargs)
  File "/var/lib/kolla/venv/lib/python3.10/site-packages/os_brick/privileged/rootwrap.py", line 145, in custom_execute
    return putils.execute(on_execute=on_execute,
  File "/var/lib/kolla/venv/lib/python3.10/site-packages/oslo_concurrency/processutils.py", line 438, in execute
    raise ProcessExecutionError(exit_code=_returncode,
oslo_concurrency.processutils.ProcessExecutionError: Unexpected error while running command.
Command: iscsiadm -m node -T iqn.2010-10.org.openstack:volume-8092f9fe-8801-4b6a-bf9e-41248c929dcb -p 172.17.0.20:3260 --login
Exit code: 20
```

[Lukas M (muhaha)]

I don't think that https://review.opendev.org/c/openstack/kolla-ansible/+/699910 is solving this use case.

[Victor Chembaev (chembervint)]

Hi

you have to start glance container in privileged mode with special extra mount, like it we tried to do here: https://review.opendev.org/c/openstack/kolla-ansible/+/854193
or here: https://review.opendev.org/c/openstack/kolla-ansible/+/714999
Also you have to have iscsid container running on node with glance and optional multipathd, if you want to manipulate images via multipath (actually it depends on storage backend and has some tricks)