Overview
Proof of Life is a simple command line application for controlling a USB Watchdog device on a Linux server.
This application is inspired by a similar Python application written by David Gouveia. His original blogpost provides a more detailed background on these devices and how they work.
In my case I was looking for a solution packaged as an all-in-one binary that avoided the hassle of installing and configuring Python and application dependencies.
Installation
Download the proof-of-life binary from the latest GitHub release or build your own (see below).
Copy the proof-of-life binary to your preferred location on the target server. As an all-in-one binary there are no other files required. No configuration file is required because all parameters are specified on the command line.
To run it via systemd, create a file called /etc/systemd/system/proof-of-life.service with the following contents. Update paths and parameters to suit your needs.
[Unit]
Description=Proof of Life Watchdog service
[Service]
Type=simple
ExecStart=/path/to/proof-of-life --port-path /dev/ttyUSB0 --timeout 300
Restart=always
[Install]
WantedBy=multi-user.target
Start the service and enable it to start on boot.
systemctl start proof-of-life
systemctl enable proof-of-lifeDevelopment
Dependencies
In order to build this application, the following dependencies must be installed.
- A working Rust toolchain. See rustup for details. At the time of writing the latest Rust version is 1.68.2.
- libudev library. On Fedora this is part of the
systemd-develpackage.
Useful commands
Build a fully optimised binary to ./target/release/proof_of_life.
cargo build --releaseBuild and run a debug binary.
cargo run -- <args>