Currently, the Gateway's state machine functions for processing packets use type-signature that only return `Option`. Any errors while processing packets are logged internally. This makes it difficult to consistently log these errors. We refactor these functions to return `Result<Option<T>>` in most cases, indicating that they may fail for various reasons and also sometimes succeed without producing an output. This allows us to consistently log these errors in the event-loop. Logging them on WARN or ERROR would be too spammy though. In order to still be alerted about some of these, we use the `telemetry_event!` macro which samples them at a rate of 1%. This will alert us about cases that happen often and allows us to handle them explicitly. Once this is deployed to staging, I will monitor the alerts in Sentry to ensure we won't get spammed with events from customers on the next release.
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:
- Ensure the binary you are profiling is compiled with the
benchprofile. sudo perf perf record -g --freq 10000 --pid $(pgrep <your-binary>).- Run the speed test or whatever load-inducing task you want to measure.
sudo perf script > profile.perf- 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.