[Manila Unity] Set unity_server_meta_pool option as required

Change-Id: Ie87b10d4199ac775adba20f645f56650bbdea301
Closes-bug: #1765580

doc/source/configuration/shared-file-systems/drivers/dell-emc-unity-driver.rst

@@ -1,5 +1,5 @@
 ================
-EMC Unity driver
+Dell EMC Unity driver
 ================
 
 The EMC Shared File Systems service driver framework (EMCShareDriver)
@@ -176,6 +176,7 @@ for the Unity driver.
 
 - ``unity_server_meta_pool``
     The name of the pool to persist the meta-data of NAS server.
+    This option is required.
 
 - ``unity_share_data_pools``
     Comma separated list specifying the name of the pools to be used

manila/share/drivers/dell_emc/plugins/unity/connection.py

@@ -43,6 +43,7 @@ SUPPORTED_NETWORK_TYPES = (None, 'flat', 'vlan')
 
 UNITY_OPTS = [
     cfg.StrOpt('unity_server_meta_pool',
+               required=True,
                deprecated_name='emc_nas_server_pool',
                help='Pool to persist the meta-data of NAS server.'),
     cfg.ListOpt('unity_share_data_pools',

manila/tests/conf_fixture.py

@@ -61,6 +61,8 @@ def set_defaults(conf):
     _safe_set_of_opts(conf, 'qnap_nas_password', 'qnapadmin')
     _safe_set_of_opts(conf, 'qnap_poolname', 'Storage Pool 1')
 
+    _safe_set_of_opts(conf, 'unity_server_meta_pool', 'nas_server_pool')
+
 
 def _safe_set_of_opts(conf, *args, **kwargs):
     try: