Use volume v3 API by default

Currently ec2api uses the volume v2 API by default, but v2 API was
deprecated a while ago and will be removed fron cinder shortly.
This patch ensures that ec2api uses the volume v3 API instead by
default.

Closes-Bug: #1908993
Change-Id: I280d3c009893c67d215b0c7106eec7fe2435c335

doc/source/configuration/tables/ec2api-clients.inc

@@ -20,7 +20,7 @@
    * - **[DEFAULT]**
      -
 
-   * - ``cinder_service_type`` = ``volumev2``
+   * - ``cinder_service_type`` = ``volumev3``
 
      - (String) Service type of Volume API, registered in Keystone catalog.
 

ec2api/clients.py

@@ -32,7 +32,7 @@ ec2_opts = [
                     'If it is obsolete v2, a lot of useful EC2 compliant '
                     'instance properties will be unavailable.'),
     cfg.StrOpt('cinder_service_type',
-               default='volumev2',
+               default='volumev3',
                help='Service type of Volume API, registered in Keystone '
                     'catalog.'),
 ]

ec2api/tests/unit/test_clients.py

@@ -116,7 +116,7 @@ class ClientsTestCase(base.BaseTestCase):
         context = mock.NonCallableMock(session=mock.sentinel.session)
         res = clients.cinder(context)
         self.assertEqual(cinder.return_value, res)
-        cinder.assert_called_with('2', service_type='volumev2',
+        cinder.assert_called_with('2', service_type='volumev3',
                                   session=mock.sentinel.session)
 
     @mock.patch('keystoneclient.client.Client')

releasenotes/notes/use-volumev3-by-default-fa726fed293d94bb.yaml

@@ -0,0 +1,6 @@
+---
+upgrade:
+  - |
+    Default value of the ``cinder_service_type`` parameter has been changed
+    from ``volumev2`` to ``volume3``, because volume v2 API was already
+    deprecated and v3 API should be used instead.