add support for barometric pressure

internal/mqttingest/mqtt.go

@@ -15,6 +15,12 @@ type MQTTConfig struct {
 	Password string
 	Topic    string
 	QoS      byte
+	Topics   []Subscription
+}
+
+type Subscription struct {
+	Topic string
+	QoS   byte
 }
 
 type Handler func(ctx context.Context, topic string, payload []byte) error
@@ -38,7 +44,22 @@ func RunSubscriber(ctx context.Context, cfg MQTTConfig, h Handler) error {
 	}
 
 	// Subscribe
-	if tok := client.Subscribe(cfg.Topic, cfg.QoS, func(_ mqtt.Client, msg mqtt.Message) {
+	subs := map[string]byte{}
+	if len(cfg.Topics) > 0 {
+		for _, sub := range cfg.Topics {
+			if sub.Topic == "" {
+				continue
+			}
+			subs[sub.Topic] = sub.QoS
+		}
+	} else if cfg.Topic != "" {
+		subs[cfg.Topic] = cfg.QoS
+	}
+	if len(subs) == 0 {
+		return fmt.Errorf("mqtt subscribe: no topics configured")
+	}
+
+	if tok := client.SubscribeMultiple(subs, func(_ mqtt.Client, msg mqtt.Message) {
 		// Keep callback short; do work with context
 		_ = h(ctx, msg.Topic(), msg.Payload())
 	}); tok.Wait() && tok.Error() != nil {