Make the admin role configurable within tempest

Adds a configuration variable for the admin role.

Change-Id: Ib7f1eaaefedebd6f0d608b0645950d0b64d87f7a
Closes-Bug: #1224742
diff --git a/etc/tempest.conf.sample b/etc/tempest.conf.sample
index 8d96858..3a33fd6 100644
--- a/etc/tempest.conf.sample
+++ b/etc/tempest.conf.sample
@@ -53,6 +53,9 @@
 # The above administrative user's tenant name
 admin_tenant_name = admin
 
+# The role that is required to administrate keystone.
+admin_role = admin
+
 [compute]
 # This section contains configuration options used when executing tests
 # against the OpenStack Compute API.
diff --git a/tempest/common/isolated_creds.py b/tempest/common/isolated_creds.py
index 22e1bd2..d6b4466 100644
--- a/tempest/common/isolated_creds.py
+++ b/tempest/common/isolated_creds.py
@@ -141,10 +141,11 @@
             role = None
             try:
                 roles = self._list_roles()
+                admin_role = self.config.identity.admin_role
                 if self.tempest_client:
-                    role = next(r for r in roles if r['name'] == 'admin')
+                    role = next(r for r in roles if r['name'] == admin_role)
                 else:
-                    role = next(r for r in roles if r.name == 'admin')
+                    role = next(r for r in roles if r.name == admin_role)
             except StopIteration:
                 msg = "No admin role found"
                 raise exceptions.NotFound(msg)
diff --git a/tempest/config.py b/tempest/config.py
index 7245b10..a010be6 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -51,6 +51,9 @@
     cfg.StrOpt('tenant_name',
                default='demo',
                help="Tenant name to use for Nova API requests."),
+    cfg.StrOpt('admin_role',
+               default='admin',
+               help="Role required to administrate keystone."),
     cfg.StrOpt('password',
                default='pass',
                help="API key to use when authenticating.",