rshutdown is a lightweight remote shutdown HTTP service for Linux.

It is primarily intended for shutting down headless Raspberry Pis cleanly when SSH access is impractical.

Packages are available for:

• x64 Debian-based Linux (*_amd64.deb), e.g. Ubuntu.
• ARM Debian-based Linux (*_armhf.deb), e.g. Raspberry Pi OS (formerly known as Raspbian) and DietPi for Raspberry Pi.

Download a .deb package file for your architecture from the Releases page.

Install the package using:

$ sudo apt install ./rshutdown_<version>_<arch>.deb

rshutdown is set up as a service (named rshutdown) when installed from one of these packages, and it will automatically start on boot.

To test that the service is working, ping it by sending it any HTTP request on the default HTTP port (3000), e.g.

$ curl localhost:3000
{"status": 1}

A random shutdown security token – which is needed to trigger the shutdown (see Usage section below) – is created when the package is installed. You can read and change its value in /etc/default/rshutdown.

Note – This file should be readable only by the rshutdown user to prevent malevolent shutdowns of the host by users that have read access to the file.

Note – After changing the variables in /etc/default/rshutdown, restart the rshutdown service with sudo service rshutdown restart for the changes to take effect.

Logs can be found in /var/log/rshutdown.

Building rshutdown from source requires CMake.

Clone the Git repository and install its submodules (the facil.io C web application framework, and the log.c logging library):

$ git clone --recurse-submodules https://github.com/spujadas/rshutdown.git

Set up the make process and compile with:

$ mkdir build && cd build
$ cmake ..
$ make -j4

Note – For testing purposes, you can compile rshutdown with the -DNO_SHUTDOWN option. When it receives an HTTP POST request with the shutdown security token, rshutdown will display a message but will not actually shut down the host.

Note – This process may require setting up a cross-compilation toolchain if compiling for another target OS, e.g. https://github.com/abhiTronix/raspberry-pi-cross-compilers for Raspberry Pi, and https://cmake.org/cmake/help/latest/manual/cmake-toolchains.7.html#cross-compiling for guidance on how to set it up with CMake.

Optionally install the rshutdown binary to /usr/bin with:

$ sudo make install

Now define a shutdown security token by setting the RSHUTDOWN_TOKEN environment variable, e.g.

$ export RSHUTDOWN_TOKEN=lIRsbdfVYnWbWfNCtZxw8GFs6PLBJ6zU

Note – The token should remain a secret, don't use this specific value.

Optionally set the RSHUTDOWN_HTTP_PORT environment variable if you want to run the service on a specific port (by default: 3000), e.g.

$ export RSHUTDOWN_HTTP_PORT=3001

Then start rshutdown with a user that has the permission to run /sbin/shutdown as root:

$ ./rshutdown

For ideas on how to set up rshutdown as a service, have a look at the pre- and post-install scripts and supporting files in the packaging directory of the project.

To shutdown a host that is running rshutdown, send it an HTTP POST request on the port that rshutdown is listening to, with the following JSON object:

{
	"token": "YOUR_SECURITY_TOKEN_HERE"
}

For example, here is how you would do this in a Windows Command Prompt using cURL:

> curl -X POST -d "{\"token\": \"YOUR_SECURITY_TOKEN_HERE\"}" http://HOSTNAME_OR_IP:3000

Here's the equivalent command on Linux:

$ curl -X POST -d '{"token": "YOUR_SECURITY_TOKEN_HERE"}' http://HOSTNAME_OR_IP:3000

If the token is valid, then the response will be JSON object {"status": 0}.

Note – If the request is invalid, then the status field will have another value: 1 for non-POST requests, and -1 for invalid POST requests (e.g. containing the wrong security token).

Hardware-based alternatives to trigger the shutdown command include:

• Using a USB device.
• Using a piece of wire or a button with two GPIO pins.

Written by Sébastien Pujadas, released under the MIT license.