-# CERTBOT_DOMAIN: Domain being authenticated. For example,
-# _acme-challenge.example.com for a wildcart cert or
-# _acme-challenge.subdomain.example.com for a subdomain
-# Note: Pass in $1 for testing or use the default of
-# CERTBOT_DOMAIN
-domain=${1:-CERTBOT_DOMAIN}
+# CERTBOT_DOMAIN: Domain being authenticated.
+# CERTBOT_VALIDATION: Validation string for domain
+#
+# Check that CERTBOT_DOMAIN and CERTBOT_VALIDATION have been passed in properly
+if [ -z "$CERTBOT_DOMAIN"]; then
+ log "CERTBOT_DOMAIN not passed in!"
+ exit 1
+else
+ log "CERTBOT_DOMAIN = $CERTBOT_DOMAIN"
+fi