Added default value for allowed_direct_url_schemes

Included 'allowed_direct_url_schemes' in driver options of
cinder configuration with a default value of 'cinder'
Also, added to unit test and functional test as part of change.

- modified cinder_purestorage.py
- modified tests_cinder_purestorage.py to include a functional test
- modified test_lib_charm_openstack_cinder_purestorage.py to
  extend the unit tests

- rebased

Closes-Bug: #1957848
Change-Id: I26a033b03f6d03fa5e68d9e26aa741c6529ecac2

src/lib/charm/openstack/cinder_purestorage.py

@@ -37,7 +37,8 @@ class CinderpurestorageCharm(
             ('pure_automatic_max_oversubscription_ratio',
                 self.config.get('automatic-max-oversubscription')),
             ('volume_driver', volumedriver),
-            ('volume_backend_name', service)]
+            ('volume_backend_name', service),
+            ('allowed_direct_url_schemes', 'cinder')]
 
         if self.config.get('protocol') == 'iscsi':
             if self.config.get('iscsi-cidr'):

src/tests/tests_cinder_purestorage.py

@@ -50,3 +50,15 @@ class CinderpurestorageTest(test_utils.OpenStackBaseTest):
             getattr(test_vol, 'os-vol-host-attr:host').split('#')[0],
             'cinder@cinder-purestorage')
         self.cinder_client.volumes.delete(vol_new)
+
+    # Check to see if allowed_direct_url_schemes gets propagated to
+    # /etc/cinder/cinder.conf
+    def test_config_propagation(self):
+        expected_contents = {
+            'cinder-purestorage': {
+                'allowed_direct_url_schemes': ['cinder']}}
+        zaza.model.block_until_oslo_config_entries_match(
+            'cinder',
+            '/etc/cinder/cinder.conf',
+            expected_contents,
+            model_name=self.model_name)

unit_tests/test_lib_charm_openstack_cinder_purestorage.py

@@ -51,4 +51,5 @@ class TestCinderpurestorageCharm(test_utils.PatchHelper):
                                   ('pure_automatic_max_oversubscription_ratio',
                                       None),
                                   ('volume_driver', None),
-                                  ('volume_backend_name', None)])
+                                  ('volume_backend_name', None),
+                                  ('allowed_direct_url_schemes', 'cinder')])