GPIO Shutdown is a simple plugin that can shutdown the Raspberry Pi if a switch connected to ground and one of the GPIO pins pressed. This plugin also turns On a led when Octoprint server is up and running. Connect a led to one of the GPIO pins and other end to ground, then set the pin number (BCM Mode) in plugin settings in web interface.

Added the option to use GPIO 3 as a shutdown pin as many users use this pin to turn on their pi, it makes sense to have one button for on/off Also added the option to use GPIO 3 as an LED pin because why not

In plugin manager from URL: https://github.com/GoldenGorilla123/OctoPrint-Gpioshutdown-Inclding-GPIO3/archive/master.zip

Via command line: pip install "https://github.com/GoldenGorilla123/OctoPrint-Gpioshutdown-Inclding-GPIO3/archive/master.zip"

In web interface, install the plugin and reload if necessary, then click on GPIO Shutdown, you will have:

• Pin Shutdown: Raspberry Pi GPIO pin (BCM Mode) your shutdown switch is attached to.
• Pin Led: Raspberry Pi GPIO pin your ready-to-run led attached to. This led will turn On when OctoPrint is up and ready to run/connect.
• Debounce Time: When press the shutdown switch, wait for this amount of time to wait for the signal to stabilize.

You can find the GPIO pin number assignments at Raspberry Pi GPIO Pinout.