Finish cleanup CONF from auth

KeystoneV3Credentials use configuration to pass add domain information if
missing. In preparation for migration to tempest-lib, remove that logic,
and move it to get_credentials in cred_provider.

Change-Id: I3adee2c047d63af55597e42c5a299dfa2c49001a
diff --git a/tempest/auth.py b/tempest/auth.py
index 7e1928f..ffeae02 100644
--- a/tempest/auth.py
+++ b/tempest/auth.py
@@ -22,13 +22,11 @@
 
 import six
 
-from tempest import config
 from tempest.openstack.common import log as logging
 from tempest.services.identity.json import token_client as json_id
 from tempest.services.identity.v3.json import token_client as json_v3id
 
 
-CONF = config.CONF
 LOG = logging.getLogger(__name__)
 
 
@@ -564,16 +562,6 @@
                   'project_name', 'tenant_id', 'tenant_name', 'user_domain_id',
                   'user_domain_name', 'user_id']
 
-    def __init__(self, **kwargs):
-        """
-        If domain is not specified, load the one configured for the
-        identity manager.
-        """
-        domain_fields = set(x for x in self.ATTRIBUTES if 'domain' in x)
-        if not domain_fields.intersection(kwargs.keys()):
-            kwargs['user_domain_name'] = CONF.identity.admin_domain_name
-        super(KeystoneV3Credentials, self).__init__(**kwargs)
-
     def __setattr__(self, key, value):
         parent = super(KeystoneV3Credentials, self)
         # for tenant_* set both project and tenant
diff --git a/tempest/common/cred_provider.py b/tempest/common/cred_provider.py
index f40ed7a..d899303 100644
--- a/tempest/common/cred_provider.py
+++ b/tempest/common/cred_provider.py
@@ -70,6 +70,12 @@
 # is none is specified
 def get_credentials(fill_in=True, identity_version=None, **kwargs):
     identity_version = identity_version or CONF.identity.auth_version
+    # In case of "v3" add the domain from config if not specified
+    if identity_version == 'v3':
+        domain_fields = set(x for x in auth.KeystoneV3Credentials.ATTRIBUTES
+                            if 'domain' in x)
+        if not domain_fields.intersection(kwargs.keys()):
+            kwargs['user_domain_name'] = CONF.identity.admin_domain_name
     return auth.get_credentials(fill_in=fill_in,
                                 identity_version=identity_version,
                                 **kwargs)