1140f6ffa3
Firezone Clients set themselves as the system-wide DNS resolver on startup. This is necessary to intercept queries for DNS resources which resolve to proxy IPs whilst Firezone is active. All DNS queries for non-resources are forwarded to either the resolver defined on the system or the ones defined in the portal (if any). These DNS servers can also be CIDR resources in which cases the queries get forwarded through the tunnel to a Gateway. Right now, the responses from these DNS servers are never cached. DNS is pretty heavily relied on on most systems and having DNS fail or be slow usually results in a bad user experience. To improve on this, we embed a small DNS cache into connlib where for each query, we first try to answer it from the cache. Queries otherwise forwarded to the system/upstream resolver or through the tunnel will see a much improved response time with this change. When serving responses from this cache, the TTL is decremented automatically based on how much time has passed since the entry was first added to the cache. Outside of the response time being ~1ms, this makes the cache fully transparent. Resolves: #10508
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.