Autoconfiguration for some heat plugin parameters

Change-Id: Iefdb991a59aedb6b6e2c687783219563411a3c67
diff --git a/tempest/tempest_ext.conf b/tempest/tempest_ext.conf
index 9667a5e..151ee19 100644
--- a/tempest/tempest_ext.conf
+++ b/tempest/tempest_ext.conf
@@ -20,27 +20,26 @@
 
 # please review and fill this section
 [heat_plugin]
-image_ref = ${IMAGE_REF2}
-username = admin
-project_name = admin
-admin_project_name = admin
+username = ${OS_USERNAME}
+admin_username = ${OS_USERNAME}
+admin_password = ${OS_PASSWORD}
+password = ${OS_PASSWORD}
+project_name = ${OS_TENANT_NAME}
+admin_project_name = ${OS_TENANT_NAME}
+region = ${OS_REGION_NAME}
+auth_url = ${OS_AUTH_URL}
 domain_name = default
-admin_username = admin
 admin_domain_name = default
 endpoint_type = internal
-auth_url = http://10.0.0.0:5000/v2.0
-admin_password = aaa
-password = aaa
+instance_type = m1.tiny
+minimal_instance_type = m1.tiny
+network_for_ssh = net_name
+floating_network_name = net_name
+fixed_subnet_name = subnet_name
 disable_ssl_certificate_validation = True
 image_ref = ${IMAGE_REF2}
 minimal_image_ref = ${IMAGE_REF2}
-instance_type = m1.tiny
-network_for_ssh = net_name
-floating_network_name = net_name
-region = RegionOne
 fixed_network_name = ${FIXED_NET}
-fixed_subnet_name = subnet_name
-minimal_instance_type = m1.tiny
 build_timeout = 180
 ssh_timeout = 30
 boot_config_env = /home/rally/boot_config_none_env.yaml