6ad10c8f39
The headless client image we ship doesn't have systemd-resolved. By
default, if you try to run it without setting the `FIREZONE_DNS_CONTROL`
var, it will exit with an unhelpful error message that is difficult to
diagnose / debug for anyone unfamiliar to the inner workings of the
headless client:
```
Error: I/O error: No such file or directory (os error 2)
Caused by:
No such file or directory (os error 2)
Stack backtrace:
0: anyhow::error::<impl core::convert::From<E> for anyhow::Error>::from
1: firezone_bin_shared::network_changes::imp::Worker::new_dbus::{{closure}}
2: firezone_headless_client::main::{{closure}}
3: tokio::runtime::runtime::Runtime::block_on
4: firezone_headless_client::main
5: std::sys::backtrace::__rust_begin_short_backtrace
6: std::rt::lang_start::{{closure}}
7: main
```
To fix this, we set `FIREZONE_DNS_CONTROL=etc-resolv-conf` for the user
inside our headless-client image.
---------
Co-authored-by: Thomas Eizinger <thomas@eizinger.io>
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
releaseprofile. sudo 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.