Files
firezone/rust
Thomas Eizinger 46afa52f78 feat(telemetry): pre-resolve Sentry ingest host (#10206)
Our Sentry client needs to resolve DNS before being able to send logs or
errors to the backend. Currently, this DNS resolution happens on-demand
as we don't take any control of the underlying HTTP client.

In addition, this will use HTTP/1.1 by default which isn't as efficient
as it could be, especially with concurrent requests.

Finally, if we decide to ever proxy all Sentry for traffic through our
own domain, we have to take control of the underlying client anyway.

To resolve all of the above, we create a custom `TransportFactory` where
we reuse the existing `ReqwestHttpTransport` but provide an already
configured `reqwest::Client` that always uses HTTP/2 with a
pre-configured set of DNS records for the given ingest host.
2025-08-21 03:28:05 +00:00
..
2023-05-10 07:58:32 -07:00

Rust development guide

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.

Reading Client logs

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

Benchmarking on Linux

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.