allow overrides for all params
diff --git a/openrc b/openrc
index e45b8fd..b79962a 100644
--- a/openrc
+++ b/openrc
@@ -32,10 +32,10 @@
# Currently novaclient needs you to specify the *compute api* version. This
# needs to match the config of your catalog returned by Keystone.
-export NOVA_VERSION=1.1
+export NOVA_VERSION=${NOVA_VERSION:-1.1}
# FIXME - why does this need to be specified?
-export NOVA_REGION_NAME=RegionOne
+export NOVA_REGION_NAME=${NOVA_REGION_NAME:-RegionOne}
# set log level to DEBUG (helps debug issues)
-export NOVACLIENT_DEBUG=1
+export NOVACLIENT_DEBUG=${NOVACLIENT_DEBUG:-0}