Fill name param in create_test_server

When calling create_test_server without name specified,
the resouce name will be something like 'tempest.common.compute-
instance-244552854', and it is hard to distinguish the testcase
from such kind of name. This is to fill name in create_test_server
which uses testcase name as prefix to help debugging.

Change-Id: I4fbc1e984e833824b820421a03d99e3a475fad3a
diff --git a/tempest/api/compute/admin/test_aggregates.py b/tempest/api/compute/admin/test_aggregates.py
index fbcc1d1..667d30b 100644
--- a/tempest/api/compute/admin/test_aggregates.py
+++ b/tempest/api/compute/admin/test_aggregates.py
@@ -215,10 +215,8 @@
         self.client.add_host(aggregate['id'], host=self.host)
         self.addCleanup(self.client.remove_host, aggregate['id'],
                         host=self.host)
-        server_name = data_utils.rand_name('test_server')
         admin_servers_client = self.os_adm.servers_client
-        server = self.create_test_server(name=server_name,
-                                         availability_zone=az_name,
+        server = self.create_test_server(availability_zone=az_name,
                                          wait_until='ACTIVE')
         body = admin_servers_client.show_server(server['id'])['server']
         self.assertEqual(self.host, body['OS-EXT-SRV-ATTR:host'])
diff --git a/tempest/api/compute/base.py b/tempest/api/compute/base.py
index 5e75493..27afff3 100644
--- a/tempest/api/compute/base.py
+++ b/tempest/api/compute/base.py
@@ -219,6 +219,8 @@
         :param validatable: Whether the server will be pingable or sshable.
         :param volume_backed: Whether the instance is volume backed or not.
         """
+        if 'name' not in kwargs:
+            kwargs['name'] = data_utils.rand_name(cls.__name__ + "-server")
         tenant_network = cls.get_tenant_network()
         body, servers = compute.create_test_server(
             cls.os,
diff --git a/tempest/api/compute/security_groups/test_security_groups.py b/tempest/api/compute/security_groups/test_security_groups.py
index f6353c8..755336f 100644
--- a/tempest/api/compute/security_groups/test_security_groups.py
+++ b/tempest/api/compute/security_groups/test_security_groups.py
@@ -94,8 +94,7 @@
 
         # Create server and add the security group created
         # above to the server we just created
-        server_name = data_utils.rand_name('server')
-        server = self.create_test_server(name=server_name)
+        server = self.create_test_server()
         server_id = server['id']
         waiters.wait_for_server_status(self.servers_client, server_id,
                                        'ACTIVE')