From 0b565ed3501044b6e8e7837cba50bb2d6f9a99c6 Mon Sep 17 00:00:00 2001
From: Kostas Chatzikokolakis <kostas@chatzi.org>
Date: Wed, 6 May 2026 08:50:49 +0300
Subject: [PATCH] Keep mqtt connection open, avoid 0s on start

---
 docker/mqtt.sh | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/docker/mqtt.sh b/docker/mqtt.sh
index 7213dc5..720366d 100644
--- a/docker/mqtt.sh
+++ b/docker/mqtt.sh
@@ -109,15 +109,19 @@ for entity in $CLEANUP_ENTITIES; do
     -t "$DISCOVERY_TOPIC" -n -r
 done
 
-# Periodic state updates
+# mosquitto_pub -l keeps the connection open and publishes each line of input, outer loop
+# reconnects on drop, use keep-alive larger than MQTT_PAUSE to avoid needless pings.
 while true; do
-  # Replace this with your real data source
-  ORB_OUTPUT="$(/app/orb summary || echo '{}')"
-  #echo "ORB_OUTPUT: $ORB_OUTPUT"
+  while true; do
+    # sleep first to avoid publishing zeroes on first iteration
+    sleep "$MQTT_PAUSE"
 
-  # Publish Orb Summary to MQTT
-  mosquitto_pub -h "$MQTT_HOST" -p "$MQTT_PORT" -u "$MQTT_USER" -P "$MQTT_PASS" \
-    -t "$STATE_TOPIC" -m "$ORB_OUTPUT" -r
+    # output a single line to mosquitto_pub
+    (/app/orb summary || echo '{}') | jq -c .
+
+  done | mosquitto_pub -h "$MQTT_HOST" -p "$MQTT_PORT" -u "$MQTT_USER" -P "$MQTT_PASS" \
+    -t "$STATE_TOPIC" -l -r -k $((MQTT_PAUSE * 2))
 
-  sleep "$MQTT_PAUSE"
+  echo "mosquitto_pub disconnected, reconnecting..."
 done
+