Isolate scenario args between iterations

We have several scenarios which modifies input data. Iterations of such
scenarios are not isolated between each other.

Also, this patch returns NeutronNetworks.create_and_update_ports scenario
from unstable to regular job.

Change-Id: Ifa5d5ecd04507edb00e9befa1c7add075010258c

rally-jobs/rally-neutron.yaml

@@ -566,6 +566,34 @@
         failure_rate:
           max: 20
 
+  NeutronNetworks.create_and_update_ports:
+    -
+      args:
+        network_create_args: {}
+        port_create_args: {}
+        ports_per_network: 5
+        port_update_args:
+            admin_state_up: False
+            device_id: "dummy_id"
+            device_owner: "dummy_owner"
+            name: "_port_updated"
+      runner:
+        type: "constant"
+        times: {{smoke or 20}}
+        concurrency: {{smoke or 10}}
+      context:
+        network: {}
+        users:
+          tenants: {{smoke or 3}}
+          users_per_tenant: {{smoke or 2}}
+        quotas:
+          neutron:
+            network: -1
+            port: -1
+      sla:
+        failure_rate:
+          max: 20
+
   Quotas.neutron_update:
     -
       args:

rally-jobs/unstable-neutron.yaml

@@ -359,31 +359,3 @@
       sla:
         failure_rate:
           max: 0
-
-  NeutronNetworks.create_and_update_ports:
-    -
-      args:
-        network_create_args: {}
-        port_create_args: {}
-        ports_per_network: 5
-        port_update_args:
-            admin_state_up: False
-            device_id: "dummy_id"
-            device_owner: "dummy_owner"
-            name: "_port_updated"
-      runner:
-        type: "constant"
-        times: {{smoke or 20}}
-        concurrency: {{smoke or 10}}
-      context:
-        network: {}
-        users:
-          tenants: {{smoke or 3}}
-          users_per_tenant: {{smoke or 2}}
-        quotas:
-          neutron:
-            network: -1
-            port: -1
-      sla:
-        failure_rate:
-          max: 20

rally/task/runner.py

@@ -15,6 +15,7 @@
 
 import abc
 import collections
+import copy
 import multiprocessing
 import time
 
@@ -50,6 +51,8 @@ def _get_scenario_context(context_obj):
 def _run_scenario_once(args):
     iteration, cls, method_name, context_obj, kwargs = args
 
+    kwargs = copy.deepcopy(kwargs)
+
     LOG.info("Task %(task)s | ITER: %(iteration)s START" %
              {"task": context_obj["task"]["uuid"], "iteration": iteration})