Get region_name that volume_driver rexray region_name needs

Config volume_driver rexray need region_name

The patch gets region_name, validates the region_name and add
Unit test.
Co-Authored By: Kai Qiang Wu(Kennan)<wkqwu@cn.ibm.com>
Co-Authored By: Ton Ngo<ton@us.ibm.com>
Partially-Implements: blueprint magnum-integrate-with-cinder
Change-Id: I3fcef0ffb7cda162fffcbedf4628cad81168d09d

magnum/common/clients.py

@@ -104,12 +104,19 @@ neutron_client_opts = [
                    'Type of endpoint in Identity service catalog to use '
                    'for communication with the OpenStack service.'))]
 
+cinder_client_opts = [
+    cfg.StrOpt('region_name',
+               help=_('Region in Identity service catalog to use for '
+                      'communication with the OpenStack service.'))]
+
+
 cfg.CONF.register_opts(magnum_client_opts, group='magnum_client')
 cfg.CONF.register_opts(heat_client_opts, group='heat_client')
 cfg.CONF.register_opts(glance_client_opts, group='glance_client')
 cfg.CONF.register_opts(barbican_client_opts, group='barbican_client')
 cfg.CONF.register_opts(nova_client_opts, group='nova_client')
 cfg.CONF.register_opts(neutron_client_opts, group='neutron_client')
+cfg.CONF.register_opts(cinder_client_opts, group='cinder_client')
 
 
 class OpenStackClients(object):
@@ -134,6 +141,10 @@ class OpenStackClients(object):
                             endpoint_type=endpoint_type,
                             region_name=region_name)
 
+    def cinder_region_name(self):
+        cinder_region_name = self._get_client_option('cinder', 'region_name')
+        return self.keystone().get_validate_region_name(cinder_region_name)
+
     @property
     def auth_url(self):
         return self.keystone().auth_url

magnum/common/exception.py

@@ -564,3 +564,7 @@ class TrusteeDeleteFailed(MagnumException):
 class QuotaAlreadyExists(Conflict):
     message = _("Quota for project %(project_id)s already exists "
                 "for resource %(resource)s.")
+
+
+class RegionsListFailed(MagnumException):
+    message = _("Failed to list regions.")

magnum/common/keystone.py

@@ -196,3 +196,28 @@ class KeystoneClientV3(object):
         except Exception:
             LOG.exception(_LE('Failed to delete trustee'))
             raise exception.TrusteeDeleteFailed(trustee_id=trustee_id)
+
+    def get_validate_region_name(self, region_name):
+        if region_name is None:
+            message = _("region_name needs to be configured in magnum.conf")
+            raise exception.InvalidParameterValue(message)
+        """matches the region of a public endpoint for the Keystone
+        service."""
+        try:
+            regions = self.client.regions.list()
+        except kc_exception.NotFound:
+            pass
+        except Exception:
+            LOG.exception(_LE('Failed to list regions'))
+            raise exception.RegionsListFailed()
+        region_list = []
+        for region in regions:
+            region_list.append(region.id)
+        if region_name not in region_list:
+            raise exception.InvalidParameterValue(_(
+                'region_name %(region_name)s is invalid, '
+                'expecting a region_name in %(region_name_list)s.') % {
+                    'region_name': region_name,
+                    'region_name_list': '/'.join(
+                        region_list + ['unspecified'])})
+        return region_name

magnum/tests/unit/common/test_keystone.py

@@ -139,3 +139,30 @@ class KeystoneClientTest(base.BaseTestCase):
             trustor_user='123456', project='654321',
             trustee_user='888888', role_names=['role3'],
             impersonation=True)
+
+    def test_get_validate_region_name(self, mock_ks):
+        key = 'region_name'
+        val = 'RegionOne'
+        cfg.CONF.set_override(key, val, 'cinder_client')
+        mock_region = mock.MagicMock()
+        mock_region.id = 'RegionOne'
+        mock_ks.return_value.regions.list.return_value = [mock_region]
+        ks_client = keystone.KeystoneClientV3(self.ctx)
+        region_name = ks_client.get_validate_region_name(val)
+        self.assertEqual('RegionOne', region_name)
+
+    def test_get_validate_region_name_not_found(self, mock_ks):
+        key = 'region_name'
+        val = 'region123'
+        cfg.CONF.set_override(key, val, 'cinder_client')
+        ks_client = keystone.KeystoneClientV3(self.ctx)
+        self.assertRaises(exception.InvalidParameterValue,
+                          ks_client.get_validate_region_name, val)
+
+    def test_get_validate_region_name_is_None(self, mock_ks):
+        key = 'region_name'
+        val = None
+        cfg.CONF.set_override(key, val, 'cinder_client')
+        ks_client = keystone.KeystoneClientV3(self.ctx)
+        self.assertRaises(exception.InvalidParameterValue,
+                          ks_client.get_validate_region_name, val)