correct secret handling

sendxmpp.sh

@@ -1,14 +1,14 @@
 #!/bin/sh
 
-[ -n PLUGIN_USERNAME ] && PLUGIN_USERNAME="${SENDXMPP_USERNAME}"
-[ -n PLUGIN_PASSWORD ] && PLUGIN_PASSWORD="${SENDXMPP_PASSWORD}"
+# set username from secret if not supplied
+[ -z $PLUGIN_USERNAME ] && [ -n $SENDXMPP_USERNAME ] && PLUGIN_USERNAME="${SENDXMPP_USERNAME}"
+[ -z $PLUGIN_PASSWORD ] && [ -n $SENDXMPP_PASSWORD ] && PLUGIN_PASSWORD="${SENDXMPP_PASSWORD}"
 
-: ${PLUGIN_USERNAME?"missing username"}
-: ${PLUGIN_JSERVER?"missing jserver"}
-: ${PLUGIN_PASSWORD?"missing password"}
-: ${PLUGIN_RECIPIENT?"missing recipient"}
-
-env | grep DRONE
+# check if all required fields are set
+[ -z "$PLUGIN_USERNAME" ] && echo "missing password or sendxmpp_password secret" && exit 1
+[ -z "$PLUGIN_PASSWORD" ] && echo "missing username or sendxmpp_username secret" && exit 1
+[ -z "$PLUGIN_JSERVER" ] && echo "missing jserver" && exit 1
+[ -z "$PLUGIN_RECIPIENT" ] && echo "missing recipient" && exit 1
 
 MSG="drone ist da"
 
@@ -21,4 +21,6 @@ CMD="sendxmpp \
 	--no-tls-verify
 	${PLUGIN_RECIPIENT}"
 
+env | grep "DRONE_"
+
 echo $MSG | $CMD