Fix rebuild_server() function

The rebuild_server() function defined in the v2 and v3 base test
classes made some incorrect assumptions about variable scoping
because the method is set as a class method. This commit fixes this
method to behave properly so that it doesn't reference variables
outside it's scope.

Change-Id: I7d0ee6e0c0784952634b157187ca47f7afbcadf1
diff --git a/tempest/api/compute/base.py b/tempest/api/compute/base.py
index 7ef5466..e3edd7c 100644
--- a/tempest/api/compute/base.py
+++ b/tempest/api/compute/base.py
@@ -181,17 +181,18 @@
         return resp, image
 
     @classmethod
-    def rebuild_server(cls, **kwargs):
+    def rebuild_server(cls, server_id, **kwargs):
         # Destroy an existing server and creates a new one
-        try:
-            cls.servers_client.delete_server(cls.server_id)
-            cls.servers_client.wait_for_server_termination(cls.server_id)
-        except Exception as exc:
-            LOG.exception(exc)
-            pass
+        if server_id:
+            try:
+                cls.servers_client.delete_server(server_id)
+                cls.servers_client.wait_for_server_termination(server_id)
+            except Exception as exc:
+                LOG.exception(exc)
+                pass
         resp, server = cls.create_test_server(wait_until='ACTIVE', **kwargs)
-        cls.server_id = server['id']
         cls.password = server['adminPass']
+        return server['id']
 
 
 class BaseV2ComputeAdminTest(BaseV2ComputeTest):
@@ -258,17 +259,17 @@
         return resp, image
 
     @classmethod
-    def rebuild_server(cls, **kwargs):
+    def rebuild_server(cls, server_id, **kwargs):
         # Destroy an existing server and creates a new one
         try:
-            cls.servers_client.delete_server(cls.server_id)
-            cls.servers_client.wait_for_server_termination(cls.server_id)
+            cls.servers_client.delete_server(server_id)
+            cls.servers_client.wait_for_server_termination(server_id)
         except Exception as exc:
             LOG.exception(exc)
             pass
         resp, server = cls.create_test_server(wait_until='ACTIVE', **kwargs)
-        cls.server_id = server['id']
         cls.password = server['admin_password']
+        return server['id']
 
 
 class BaseV3ComputeAdminTest(BaseV3ComputeTest):
diff --git a/tempest/api/compute/images/test_images_oneserver.py b/tempest/api/compute/images/test_images_oneserver.py
index 612c110..18e32d8 100644
--- a/tempest/api/compute/images/test_images_oneserver.py
+++ b/tempest/api/compute/images/test_images_oneserver.py
@@ -49,7 +49,7 @@
             LOG.exception(exc)
             # Rebuild server if cannot reach the ACTIVE state
             # Usually it means the server had a serius accident
-            self.rebuild_server()
+            self.server_id = self.rebuild_server(self.server_id)
 
     @classmethod
     def setUpClass(cls):
diff --git a/tempest/api/compute/images/test_images_oneserver_negative.py b/tempest/api/compute/images/test_images_oneserver_negative.py
index b4e778c..4cd41ee 100644
--- a/tempest/api/compute/images/test_images_oneserver_negative.py
+++ b/tempest/api/compute/images/test_images_oneserver_negative.py
@@ -50,7 +50,7 @@
             LOG.exception(exc)
             # Rebuild server if cannot reach the ACTIVE state
             # Usually it means the server had a serius accident
-            self.rebuild_server()
+            self.server_id = self.rebuild_server(self.server_id)
 
     @classmethod
     def setUpClass(cls):
diff --git a/tempest/api/compute/servers/test_server_actions.py b/tempest/api/compute/servers/test_server_actions.py
index 5abde56..2656e8a 100644
--- a/tempest/api/compute/servers/test_server_actions.py
+++ b/tempest/api/compute/servers/test_server_actions.py
@@ -45,13 +45,13 @@
             self.client.wait_for_server_status(self.server_id, 'ACTIVE')
         except Exception:
             # Rebuild server if something happened to it during a test
-            self.rebuild_server()
+            self.server_id = self.rebuild_server(self.server_id)
 
     @classmethod
     def setUpClass(cls):
         super(ServerActionsTestJSON, cls).setUpClass()
         cls.client = cls.servers_client
-        cls.rebuild_server()
+        cls.server_id = cls.rebuild_server(None)
 
     @testtools.skipUnless(compute.CHANGE_PASSWORD_AVAILABLE,
                           'Change password not available.')
diff --git a/tempest/api/compute/servers/test_servers_negative.py b/tempest/api/compute/servers/test_servers_negative.py
index 5ec0cbe..7b86d2d 100644
--- a/tempest/api/compute/servers/test_servers_negative.py
+++ b/tempest/api/compute/servers/test_servers_negative.py
@@ -34,7 +34,7 @@
         try:
             self.client.wait_for_server_status(self.server_id, 'ACTIVE')
         except Exception:
-            self.rebuild_server()
+            self.server_id = self.rebuild_server(self.server_id)
 
     @classmethod
     def setUpClass(cls):
diff --git a/tempest/api/compute/v3/servers/test_server_actions.py b/tempest/api/compute/v3/servers/test_server_actions.py
index 92b9e30..0e4bcd1 100644
--- a/tempest/api/compute/v3/servers/test_server_actions.py
+++ b/tempest/api/compute/v3/servers/test_server_actions.py
@@ -45,13 +45,13 @@
             self.client.wait_for_server_status(self.server_id, 'ACTIVE')
         except Exception:
             # Rebuild server if something happened to it during a test
-            self.rebuild_server()
+            self.server_id = self.rebuild_server(self.server_id)
 
     @classmethod
     def setUpClass(cls):
         super(ServerActionsV3TestJSON, cls).setUpClass()
         cls.client = cls.servers_client
-        cls.rebuild_server()
+        cls.server_id = cls.rebuild_server(None)
 
     @testtools.skipUnless(compute.CHANGE_PASSWORD_AVAILABLE,
                           'Change password not available.')
diff --git a/tempest/api/compute/v3/servers/test_servers_negative.py b/tempest/api/compute/v3/servers/test_servers_negative.py
index 5ec0cbe..7b86d2d 100644
--- a/tempest/api/compute/v3/servers/test_servers_negative.py
+++ b/tempest/api/compute/v3/servers/test_servers_negative.py
@@ -34,7 +34,7 @@
         try:
             self.client.wait_for_server_status(self.server_id, 'ACTIVE')
         except Exception:
-            self.rebuild_server()
+            self.server_id = self.rebuild_server(self.server_id)
 
     @classmethod
     def setUpClass(cls):