Deprecate default value for v3_endpoint_type

To make endpoint_type default values consistent across services,
keystone v3_endpoint_type default value is deprecated in Pike and
will be changed to publicURL in next release

Change-Id: Iacdfb61e718b8ae45eab25e8041829989486a2ed
Closes-Bug: #1687141
diff --git a/releasenotes/notes/deprecate-default-value-for-v3_endpoint_type-fb9e47c5ba1c719d.yaml b/releasenotes/notes/deprecate-default-value-for-v3_endpoint_type-fb9e47c5ba1c719d.yaml
new file mode 100644
index 0000000..c88522e
--- /dev/null
+++ b/releasenotes/notes/deprecate-default-value-for-v3_endpoint_type-fb9e47c5ba1c719d.yaml
@@ -0,0 +1,6 @@
+---
+deprecations:
+  - |
+    Deprecate default value for configuration parameter v3_endpoint_type
+    of identity section in OpenStack Pike and modify the default value to
+    publicURL in OpenStack Q release.
diff --git a/tempest/config.py b/tempest/config.py
index f5b2f0d..2585034 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -161,7 +161,9 @@
                choices=['public', 'admin', 'internal',
                         'publicURL', 'adminURL', 'internalURL'],
                help="The endpoint type to use for OpenStack Identity "
-                    "(Keystone) API v3"),
+                    "(Keystone) API v3. The default value adminURL is "
+                    "deprecated and will be modified to publicURL in "
+                    "the next release."),
     cfg.StrOpt('admin_role',
                default='admin',
                help="Role required to administrate keystone."),