Add rally hook to neutron devstack plugin

This allows us to configure neutron when running the rally job in
the gate. This effort stems from patch [1]. Blame Kevin for not
wanting to squash the two together.

[1] I12aaf6121b677e9696131601b3539a7091e2858c
Change-Id: I006957784ac7900021bcfee57cbc83b5a6c533c4

TESTING.rst

@@ -358,6 +358,19 @@ http://docs.openstack.org/developer/tempest/field_guide/scenario.html
 Scenario tests, like API tests, are split between the Tempest and Neutron
 repositories according to the Neutron API the test is targeting.
 
+Rally Tests
+~~~~~~~~~~~
+
+Rally tests (rally-jobs/plugins) use the `rally <http://rally.readthedocs.io/>`_
+infrastructure to exercise a neutron deployment. Guidelines for writing a
+good rally test can be found in the `rally plugin documentation <http://rally.readthedocs.io/en/latest/plugins.html>`_.
+There are also some examples in tree; the process for adding rally plugins to
+neutron requires three steps: 1) write a plugin and place it under rally-jobs/plugins/.
+This is your rally scenario; 2) (optional) add a setup file under rally-jobs/extra/.
+This is any devstack configuration required to make sure your environment can
+successfully process your scenario requests; 3) edit neutron-neutron.yaml. This
+is your scenario 'contract' or SLA.
+
 Development Process
 -------------------
 

devstack/lib/rally

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+RALLY_EXTRA_DIR="$DEST/neutron/rally-jobs/extra"
+
+# If rally has been configured, .setup files can be sourced to control the
+# neutron configuration required to run the scenario plugins.
+if [[ "$DEVSTACK_PLUGINS" =~ "rally" ]];
+then
+    for file in $(ls $RALLY_EXTRA_DIR/*.setup);
+    do
+        source $file
+    done
+fi

devstack/plugin.sh

@@ -7,6 +7,7 @@ source $LIBDIR/l2_agent_sriovnicswitch
 source $LIBDIR/ml2
 source $LIBDIR/qos
 source $LIBDIR/ovs
+source $LIBDIR/rally
 source $LIBDIR/trunk
 
 Q_BUILD_OVS_FROM_GIT=$(trueorfalse False Q_BUILD_OVS_FROM_GIT)

rally-jobs/extra/trunk_scenario.setup

@@ -0,0 +1 @@
+enable_service q-trunk