Firezone uses Rust for all data plane components. This directory contains the Linux and Windows clients, and low-level networking implementations related to STUN/TURN.

We target the last stable release of Rust using rust-toolchain.toml. If you are using rustup, that is automatically handled for you. Otherwise, ensure you have the latest stable version of Rust installed.

Install system dependencies:

sudo apt-get install build-essential pkg-config libgtk-3-dev libsoup-3.0-dev libayatana-appindicator3-dev librsvg2-dev libssl-dev libwebkit2gtk-4.1-dev libxdo-dev

Install the eBPF toolchain and linker (required by the relay crate):

rustup toolchain install nightly-2025-05-30
rustup component add rust-src --toolchain nightly-2025-05-30
cargo install bpf-linker

The Client logs are written as JSONL for machine-readability.

To make them more human-friendly, pipe them through jq like this:

cd path/to/logs  # e.g. `$HOME/.cache/dev.firezone.client/data/logs` on Linux
cat *.log | jq -r '"\(.time) \(.severity) \(.message)"'

Resulting in, e.g.

2024-04-01T18:25:47.237661392Z INFO started log
2024-04-01T18:25:47.238193266Z INFO GIT_VERSION = 1.0.0-pre.11-35-gcc0d43531
2024-04-01T18:25:48.295243016Z INFO No token / actor_name on disk, starting in signed-out state
2024-04-01T18:25:48.295360641Z INFO null

The recommended way for benchmarking any of the Rust components is Linux' perf utility. For example, to attach to a running application, do:

1. Ensure the binary you are profiling is compiled with the release profile.
2. sudo perf record -g --freq 10000 --pid $(pgrep <your-binary>).
3. Run the speed test or whatever load-inducing task you want to measure.
4. sudo perf script > profile.perf
5. Open profiler.firefox.com and load profile.perf

Instead of attaching to a process with --pid, you can also specify the path to executable directly. That is useful if you want to capture perf data for a test or a micro-benchmark.