pingshutdown can be used to shutdown a host when another remote host is no longer responding to ping.

A potential use of this is safely shutting down a host connected to a UPS on power failure. While many UPSes work with apcupsd or nut to provide this notification, pingshutdown can be used in any hardware configuration.

pingshutdown also provides the ability to notify on pending shutdown via Pushover, and offers a web interface to see timer status as well as temporarily disable the shutdown functionality.

pingshutdown is intended to run as a systemd unit, either installed manually or using the included NixOS module.

To install manually, build the application as

go build ./cmd/pingshutdown

and put the binary in your PATH (e.g. /usr/local/bin).

Then, copy the included pingshutdown.service into /etc/systemd/system and create an EnvironmentFile in /etc/default/pingshutdown.env containing your desired configuration (see pingshutdown.env for example syntax).

To install using the NixOS module, add this repository to your flake.nix as

inputs.pingshutdown.url = "github:devusb/pingshutdown";

and import the module in your NixOS configuration as

imports = [
    inputs.pingshutdown.nixosModules.pingshutdown
];

then, enable the service in your NixOS configuration as

services.pingshutdown = {
  enable = true;
  environmentFile = /run/secrets/pushover;
  settings = {
    PINGSHUTDOWN_DELAY = "10m";
    PINGSHUTDOWN_TARGET = "192.168.20.1";
    PINGSHUTDOWN_NOTIFICATION = "true";
    PINGSHUTDOWN_DRYRUN = "false";
    PINGSHUTDOWN_STATUSPORT = "9081";
  };
};

where environmentFile can contain additional settings such as a Pushover token to be used for notifications.

Configuration is via environment variables, options are listed below

• PINGSHUTDOWN_DELAY - amount of time to wait before initiating system shutdown (default 5m)
• PINGSHUTDOWN_TARGET - remote host to ping (default www.google.com)
• PINGSHUTDOWN_NOTIFICATON - enable notification of shutdown status via Pushover (default false)
• PINGSHUTDOWN_NOTIFICATONTOKEN - Pushover application API token
• PINGSHUTDOWN_NOTIFICATIONUSER - Pushover user key to be notified
• PINGSHUTDOWN_DRYRUN - whether to actually shut down machine -- true will only initiate countdown and notification, but will not shut down (default false)
• PINGSHUTDOWN_STATUSPORT - port to serve status web interface (default 8081)

When started, pingshutdown will begin pinging the target, and upon ping failures occuring for 10 seconds, will begin a timer after which the host system will be shut down.

When the timer begins, an optional notification will be set to the Pushover user specified via the PINGSHUTDOWN_NOTIFICATONUSER environment variable.

A web interface is available at the port configure via PINGSHUTDOWN_STATUSPORT that shows timer status and enables locking out (disabling) the shutdown functionality, as might be necessary during network maintenance.