Add variable to configure the run of IPv6 Tests

Related Tempest change:
  https://review.openstack.org/#/c/74933/

Closes-bug: 1282387

Change-Id: If9e9c5319c484dc4c00ed3bdcefc132410719b87
diff --git a/lib/tempest b/lib/tempest
index 596750b..d2227fe 100644
--- a/lib/tempest
+++ b/lib/tempest
@@ -63,6 +63,9 @@
 TEMPEST_VOLUME_VENDOR=${TEMPEST_VOLUME_VENDOR:-"Open Source"}
 TEMPEST_STORAGE_PROTOCOL=${TEMPEST_STORAGE_PROTOCOL:-iSCSI}
 
+# Neutron/Network variables
+IPV6_ENABLED=$(trueorfalse True $IPV6_ENABLED)
+
 # Functions
 # ---------
 
@@ -285,11 +288,13 @@
     # Compute admin
     iniset $TEMPEST_CONFIG "compute-admin" password "$password" # DEPRECATED
 
+    # Network
     iniset $TEMPEST_CONFIG network api_version 2.0
     iniset $TEMPEST_CONFIG network tenant_networks_reachable "$tenant_networks_reachable"
     iniset $TEMPEST_CONFIG network public_network_id "$public_network_id"
     iniset $TEMPEST_CONFIG network public_router_id "$public_router_id"
     iniset $TEMPEST_CONFIG network default_network "$FIXED_RANGE"
+    iniset $TEMPEST_CONFIG network ipv6_enabled "$IPV6_ENABLED"
 
     # boto
     iniset $TEMPEST_CONFIG boto ec2_url "http://$SERVICE_HOST:8773/services/Cloud"