Solving Linux Desktop Notifications with MQTT and OpenHAB

General
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I’ve been diving into the world of home automation with OpenHAB and MQTT, and I wanted to share my journey in solving a notification issue on my Linux desktop. While I’ve successfully integrated notifications to my mobile devices and TVs using Pushover and Notifications for Android, my Linux desktop remained a challenge until recently.

The Challenge

My setup includes an OpenHAB installation on a Raspberry Pi and a separate Linux desktop running Ubuntu on the same LAN. My goal was to send MQTT messages from my main OpenHAB server to my desktop, triggering notifications directly on my Gnome desktop. I discovered that using notify-send was the perfect solution for sending popup notifications, but there was a hurdle: security restrictions prevented the OpenHAB user from sending notifications to my desktop user’s session.

The Solution

After some research and experimentation, I found a workaround that leverages MQTT and OpenHAB’s flexibility. Here’s how I did it:

  1. MQTT Integration: I configured MQTT on both my OpenHAB server and Linux desktop. This allowed me to send messages between the two devices seamlessly.
  2. Exec Binding: Using OpenHAB’s exec binding, I set up a rule that triggers an executable script on my desktop whenever an MQTT message is received. This script uses notify-send to display the notification.
  3. Security Workaround: To bypass the security restrictions, I created a small script that runs with elevated privileges, enabling the notification to appear on my desktop session.

The Result

Now, I can send notifications from OpenHAB to my Linux desktop with ease. This integration has been a game-changer for my home automation setup, allowing me to stay informed regardless of where I am in my home.

Tips for Others

  • MQTT Configuration: Ensure both your OpenHAB server and desktop are correctly configured to communicate over MQTT.
  • Scripting: Don’t hesitate to use small scripts to handle tasks that OpenHAB alone can’t manage. This can often be the quickest way to achieve the desired functionality.
  • Security: Always be cautious with scripts that require elevated privileges. Make sure they are necessary and secure.

I hope this experience helps others facing similar challenges. Happy automating!