Add POD and REGION as ARGS and set to environment variables.

Dockerfile

@@ -9,8 +9,10 @@ MAINTAINER Eric Schoville <>
 # The values for POD and REGION probably need changing for you.  Setting these as
 # default for UW-Madison hosted service
 
-ENV POD=usw3
-ENV REGION=dm-us
+ARG POD=usw3
+ARG REGION=dm-us
+ENV POD=$POD 
+ENV REGION=$REGION
 
 # You should be able to download the Secure Agent binary from the following URL without authentication: