Change transport_url in grenade-multinode job

* Change transport_url to test Heat's upgrade strategy [1] in gate.

[1] https://review.openstack.org/475853/

Change-Id: I08770d2ae09891d7983345616186cff7c26df4ce

devstack/upgrade/settings

@@ -4,3 +4,5 @@ devstack_localrc base enable_service h-api h-api-cfn h-eng heat tempest
 devstack_localrc target enable_service h-api h-api-cfn h-eng heat tempest
 BASE_RUN_SMOKE=False
 TARGET_RUN_SMOKE=False
+
+export HOST_TOPOLOGY=${HOST_TOPOLOGY}

devstack/upgrade/upgrade.sh

@@ -58,6 +58,7 @@ source $TARGET_DEVSTACK_DIR/stackrc
 source $TARGET_DEVSTACK_DIR/lib/tls
 source $TARGET_DEVSTACK_DIR/lib/stack
 source $TARGET_DEVSTACK_DIR/lib/apache
+source $TARGET_DEVSTACK_DIR/lib/rpc_backend
 
 # Get heat functions from devstack plugin
 source $HEAT_DEVSTACK_DIR/lib/heat
@@ -72,6 +73,13 @@ set -o xtrace
 # Install the target heat
 source $HEAT_DEVSTACK_DIR/plugin.sh stack install
 
+# Change transport-url in the host which runs upgrade script (primary)
+if [[ "${HOST_TOPOLOGY}" == "multinode" ]]; then
+    vhost="newvhost"
+    rpc_backend_add_vhost $vhost
+    iniset_rpc_backend heat $HEAT_CONF DEFAULT $vhost
+fi
+
 # calls upgrade-heat for specific release
 upgrade_project heat $RUN_DIR $BASE_DEVSTACK_BRANCH $TARGET_DEVSTACK_BRANCH
 

playbooks/devstack/grenade/run.yaml

@@ -52,6 +52,7 @@
               export OVERRIDE_ZUUL_BRANCH=$BRANCH_OVERRIDE
           fi
           export DEVSTACK_GATE_TOPOLOGY="{{ topology }}"
+          export DEVSTACK_LOCAL_CONFIG=$'\n'"HOST_TOPOLOGY={{ topology }}"
           cp devstack-gate/devstack-vm-gate-wrap.sh ./safe-devstack-vm-gate-wrap.sh
           ./safe-devstack-vm-gate-wrap.sh
         executable: /bin/bash