MQTT - Signal-Cli Gateway

This is a lightweight, single file mqtt to signal-cli gateway written in python. It is assumed that signal-cli is running as a username independent dbus service (without the "-u" option) on the system. The gateway connects to the service and sends messages from signal to the topic.

This is an PoC and not really intented for production usage.

signal/from/<phonenumberwithout+sign

Mqtt publishes to the optic

signal/to/<phonenumberwithout+sign>

are send to the corresponding number via signal. For security it has to be set a set of "known numbers" which are allowed to participate to the whole process.

Additionally there is a /help which atm only shows the command /ping which sends a publish to the topic

signal/ping

with the ping requester phone number as payload. The gateway subscribes to this topic too and sends back a chat message /pong if it receives the sent message back (lightweight application level ping)

Lastly the Gateway will publish a message "1" to

signal/<clientId>

when connecting and a will message "0" to the same topic, to make the presence visible on mqtt level. This can be prevented by the corresponding parameter

Installation

• Get signal-cli going on your system and start it as a dbus service (https://github.com/AsamK/signal-cli/wiki/DBus-service)
• make sure the number you want to use is registered and the dbus service can handle it
• Put the files where you need them
  • main.py wherever you want (has to be executable)
  • app.ini wherever you want (see example file)
  • mqtt-signal-gateway.service under /etc/systemd/system (adjust the paths in the service file to your need)
• enable and start the service
  • systemctl enable mqtt-signal-gateway
  • systemctl start mqtt-signal-gateway

Dependencies

• signal-cli running as a phone number (user) independent dbus service
• registered phone number via signal-cli
• python3
  • pydbus
  • paho-mqtt
  • GLib

Special thanks

To AsamK for creating signal-cli (https://github.com/AsamK/signal-cli)