mqcontrol

mqcontrol is a lightweight and cross-platform utility which subscribes to an MQTT topic and executes a predefined command on your computer whenever a message appears. It's an easy way to make your PC part of your home automation or IoT system!

Installation

See the releases page and download a binary for your operating system and architecture.

Or install it with Go:

go install github.com/albertnis/mqcontrol

To complete local installation, add mqcontrol to PATH and/or run it at startup.

Docker

mqcontrol is available on Docker Hub: albertnis/mqcontrol. The images are cross-platform and available in a variety of flavours. See the Docker Hub overview for more information.

docker run albertnis/mqcontrol --help

Usage

Configuration is via command-line arguments.

mqcontrol --help
  -c string
        Command to run when any message received on topic
  -h string
        Address and port of MQTT broker (default "127.0.0.1:1883")
  -i string
        ID to use for this client (default "mqcontrol-{randomString}")
  -t string
        Topic to subscribe to (default "computer/command")
  -u string
        Username for MQTT connection
  -p string
        Password for MQTT connection

Examples

Make a topic to hibernate your PC

mqcontrol -c "systemctl hibernate" -t desktop/command/hibernate

Dim laptop screen when the lights are turned off

mqcontrol -c "brightnessctl 50%-" -t lights/bedroom/turnoff

Close gzdoom when the office door is opened

mqcontrol -c "killall gzdoom" -t work/office/door/open

Notes

The command argument does not include any shell processing. If you're having problems getting commands to run or want them to run in a shell, specify the shell in the command. For example:
```
mqcontrol -c "/bin/sh -c \"echo message received\"" -t desktop/command/hibernate
```
An error in the executed command will cause the entire program to terminate. Stderr and an exit code from the executed command will be available.

Run the code locally

Get then run with Go:

go get github.com/albertnis/mqcontrol
go run github.com/albertnis/mqcontrol -c "echo Message received"

Run with Go in cloned repo:

go run main.go -c "echo Message received"

With Docker (BuildKit):

DOCKER_BUILDKIT=1 docker build -t mqcontrol .
docker run -it --rm --network=host mqcontrol -c "echo Message received"

With docker-compose (BuildKit):

COMPOSE_DOCKER_CLI_BUILD=1 DOCKER_BUILDKIT=1 docker-compose build
docker-compose run mqcontrol -c "echo Message received"

Run it at startup

On Windows using Task Scheduler

Open Task Scheduler and select Action -> Create Task from the menu bar.
On the "General" tab, select "Run whether the user is logged in or not" and check "Do not store password...".
On the "Triggers" tab, create a new trigger. Use "On startup" or "At log on".
On the "Actions" tab, create a new action pointing to your mqcontrol binary with desired arguments.
Configure the remaining tabs as desired then click "OK".
Browse to the newly created task under the "Task Scheduler Library". Right click on the task and select "Run".

On Linux using systemd

Create a systemd unit file as below, customise the ExecStart line, then save it at /usr/lib/systemd/system/mqcontrol.service:

[Unit]
Description=mqcontrol remote control

[Service]
Type=simple
ExecStart=/home/user/go/bin/mqcontrol -i mqclinux -c "systemctl hibernate" -h 192.168.1.110:1883

[Install]
WantedBy=multi-user.target

Start and enable the mqcontrol service

systemctl start mqcontrol
systemctl enable mqcontrol

# README