Add HA watchdog

ha_watchdog.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+HA_URL="http://localhost:8123"
+STATE_FILE="/tmp/ha_watchdog_state"
+
+if curl -s -m 10 "$HA_URL" > /dev/null; then
+    echo "0" > "$STATE_FILE"
+else
+    STATE="0"
+    if [ -f "$STATE_FILE" ]; then
+        STATE=$(cat "$STATE_FILE")
+    fi
+    
+    if [ "$STATE" -eq 1 ]; then
+        # Already tried restarting once, failed again -> Reboot
+        echo "0" > "$STATE_FILE"
+        sudo reboot
+    else
+        # Try returning the container to life
+        docker restart HomeAssistant
+        echo "1" > "$STATE_FILE"
+    fi
+fi