From c46817d8d2bcc87ce601de1feae8b21683aa70ef Mon Sep 17 00:00:00 2001
From: Wolfgang Hottgenroth <wolfgang.hottgenroth@icloud.com>
Date: Sat, 25 Nov 2023 12:26:08 +0100
Subject: [PATCH] error messages for missing env vars

---
 main.go | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/main.go b/main.go
index 05fdc41..cbcab11 100644
--- a/main.go
+++ b/main.go
@@ -25,6 +25,9 @@ func onReconnecting(client MQTT.Client, clientOpts *MQTT.ClientOptions) {
 
 func onConnect(client MQTT.Client) {
   topicsStr := os.Getenv("MQTT_SUBSCRIBE_TOPICS")
+  if topicsStr == "" {
+    log.Fatal("No topics given, set env var MQTT_SUBSCRIBE_TOPICS")
+  }
   topics := strings.Split(topicsStr, ",")
   for _, topic := range topics {
     if token := client.Subscribe(topic, 0, onMessageReceived); token.Wait() && token.Error() != nil {
@@ -42,6 +45,9 @@ func main() {
   log.Println("UDI starting")
 
   broker := os.Getenv("MQTT_BROKER")
+  if broker == "" {
+    log.Fatal("No broker given, set env var MQTT_BROKER")
+  }
 
   prefix := "UDI"
   uuid := uuid.New()