Add test for showing encryption specs item

This patch adds test for the missing API (volume v2):
show specific encryption specs item for a volume type.

Including:

[1] Add show encryption specs item API to v2 encryption_types_client
[2] Add unit test for the API
[3] Modify test case: test_volume_type_encryption_create_get_update_delete
[4] Add release note

Change-Id: Idd91e39716f4acf6796412f3f67ef8b6771916f9

releasenotes/notes/add-show-encryption-specs-item-api-to-v2-encryption-types-client-290b421cd4bc0c0e.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Add show encryption specs item API to v2 encryption_types_client library.
+    This feature enables the possibility to show specific encryption specs for
+    a volume type.

tempest/api/volume/admin/test_volume_types.py

@@ -161,6 +161,12 @@ class VolumeTypesTest(base.BaseVolumeAdminTest):
                              'The fetched encryption_type %s is different '
                              'from the updated encryption_type' % key)
 
+        # Get encryption specs item
+        key = 'cipher'
+        item = self.admin_encryption_types_client.show_encryption_specs_item(
+            encrypt_type_id, key)
+        self.assertEqual(update_kwargs[key], item[key])
+
         # Delete encryption type
         self.admin_encryption_types_client.delete_encryption_type(
             encrypt_type_id)

tempest/lib/services/volume/v2/encryption_types_client.py

@@ -47,6 +47,14 @@ class EncryptionTypesClient(rest_client.RestClient):
         self.expected_success(200, resp.status)
         return rest_client.ResponseBody(resp, body)
 
+    def show_encryption_specs_item(self, volume_type_id, key):
+        """Get the encryption specs item for the specified volume type."""
+        url = "/types/%s/encryption/%s" % (volume_type_id, key)
+        resp, body = self.get(url)
+        body = json.loads(body)
+        self.expected_success(200, resp.status)
+        return rest_client.ResponseBody(resp, body)
+
     def create_encryption_type(self, volume_type_id, **kwargs):
         """Create encryption type.
 

tempest/tests/lib/services/volume/v2/test_encryption_types_client.py

@@ -43,6 +43,10 @@ class TestEncryptionTypesClient(base.BaseServiceTest):
         }
     }
 
+    FAKE_ENCRYPTION_SPECS_ITEM = {
+        "cipher": "aes-xts-plain64"
+    }
+
     def setUp(self):
         super(TestEncryptionTypesClient, self).setUp()
         fake_auth = fake_auth_provider.FakeAuthProvider()
@@ -65,6 +69,13 @@ class TestEncryptionTypesClient(base.BaseServiceTest):
             self.FAKE_INFO_ENCRYPTION_TYPE,
             bytes_body, volume_type_id="cbc36478b0bd8e67e89")
 
+    def _test_show_encryption_specs_item(self, bytes_body=False):
+        self.check_service_client_function(
+            self.client.show_encryption_specs_item,
+            'tempest.lib.common.rest_client.RestClient.get',
+            self.FAKE_ENCRYPTION_SPECS_ITEM,
+            bytes_body, volume_type_id="cbc36478b0bd8e67e89", key="cipher")
+
     def test_create_encryption_type_with_str_body(self):
         self._test_create_encryption()
 
@@ -77,6 +88,12 @@ class TestEncryptionTypesClient(base.BaseServiceTest):
     def test_show_encryption_type_with_bytes_body(self):
         self._test_show_encryption_type(bytes_body=True)
 
+    def test_show_encryption_specs_item_with_str_body(self):
+        self._test_show_encryption_specs_item()
+
+    def test_show_encryption_specs_item_with_bytes_body(self):
+        self._test_show_encryption_specs_item(bytes_body=True)
+
     def test_delete_encryption_type(self):
         self.check_service_client_function(
             self.client.delete_encryption_type,