Remove deprecated config options 'resources_prefix'

Config option 'resources_prefix' was deprecated. It is
used by only manila plugin which fix has been commited.

This commit removes this config option and hardcode the
resource prefix as 'tempest'

Change-Id: Idce7af97fe6647e3095b2b626fbacb3446694fbc
Depends-On: I9c140b3a9efabeced7fc26cb1f169ebe6789d88b
diff --git a/doc/source/library/credential_providers.rst b/doc/source/library/credential_providers.rst
index d96c97a..d25f85c 100644
--- a/doc/source/library/credential_providers.rst
+++ b/doc/source/library/credential_providers.rst
@@ -49,7 +49,7 @@
               public_network_id=CONF.network.public_network_id,
               create_networks=(CONF.auth.create_isolated_networks and not
                                CONF.network.shared_physical_network),
-              resource_prefix=CONF.resources_prefix,
+              resource_prefix='tempest',
               credentials_domain=CONF.auth.default_credentials_domain_name,
               admin_role=CONF.identity.admin_role,
               identity_uri=CONF.identity.uri_v3,
diff --git a/releasenotes/notes/removal-deprecated-config-options-3db535b979fe3509.yaml b/releasenotes/notes/removal-deprecated-config-options-3db535b979fe3509.yaml
index 2b3bb3a..0b03e21 100644
--- a/releasenotes/notes/removal-deprecated-config-options-3db535b979fe3509.yaml
+++ b/releasenotes/notes/removal-deprecated-config-options-3db535b979fe3509.yaml
@@ -7,3 +7,4 @@
 
     * ``[identity-feature-enabled].forbid_global_implied_dsr``
     * ``[image-feature-enabled].deactivate_image``
+    * ``[default].resources_prefix``
diff --git a/tempest/api/object_storage/test_account_services.py b/tempest/api/object_storage/test_account_services.py
index 3bbab11..c5c30e3 100644
--- a/tempest/api/object_storage/test_account_services.py
+++ b/tempest/api/object_storage/test_account_services.py
@@ -241,7 +241,7 @@
     @decorators.idempotent_id('365e6fc7-1cfe-463b-a37c-8bd08d47b6aa')
     def test_list_containers_with_prefix(self):
         # list containers that have a name that starts with a prefix
-        prefix = '{0}-a'.format(CONF.resources_prefix)
+        prefix = 'tempest-a'
         params = {'prefix': prefix}
         resp, container_list = self.account_client.list_account_containers(
             params=params)
diff --git a/tempest/common/credentials_factory.py b/tempest/common/credentials_factory.py
index da34975..75db155 100644
--- a/tempest/common/credentials_factory.py
+++ b/tempest/common/credentials_factory.py
@@ -86,7 +86,7 @@
         ('public_network_id', CONF.network.public_network_id),
         ('create_networks', (CONF.auth.create_isolated_networks and not
                              CONF.network.shared_physical_network)),
-        ('resource_prefix', CONF.resources_prefix),
+        ('resource_prefix', 'tempest'),
         ('identity_admin_endpoint_type', endpoint_type)
     ]))
 
diff --git a/tempest/common/utils/__init__.py b/tempest/common/utils/__init__.py
index aa81864..225a713 100644
--- a/tempest/common/utils/__init__.py
+++ b/tempest/common/utils/__init__.py
@@ -31,10 +31,9 @@
 
         if attr == 'rand_name':
             # NOTE(flwang): This is a proxy to generate a random name that
-            # includes a random number and a prefix if one is configured in
-            # CONF.resources_prefix
+            # includes a random number and a prefix 'tempest'
             attr_obj = partial(lib_data_utils.rand_name,
-                               prefix=CONF.resources_prefix)
+                               prefix='tempest')
         else:
             attr_obj = getattr(lib_data_utils, attr)
 
diff --git a/tempest/config.py b/tempest/config.py
index 4544871..bc585cb 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -1064,17 +1064,6 @@
 ]
 
 DefaultGroup = [
-    cfg.StrOpt('resources_prefix',
-               default='tempest',
-               help="Prefix to be added when generating the name for "
-                    "test resources. It can be used to discover all "
-                    "resources associated with a specific test run when "
-                    "running tempest on a real-life cloud",
-               deprecated_for_removal=True,
-               deprecated_reason="It is enough to add 'tempest' as this "
-                                 "prefix to ideintify resources which are "
-                                 "created by Tempest and no projects set "
-                                 "this option on OpenStack dev community."),
     cfg.BoolOpt('pause_teardown',
                 default=False,
                 help="""Whether to pause a test in global teardown.