Servlin

A modular HTTP server library in Rust.

Features

• forbid(unsafe_code)
• Threaded request handlers: FnOnce(Request) -> Response + 'static + Clone + Send + Sync
• Uses async code internally for excellent performance under load
• JSON
• Server-Sent Events (SSE)
• Saves large request bodies to temp files
• Sends 100-Continue
• Limits number of threads and connections
• Modular: roll your own logging, write custom versions of internal methods, etc.
• No macros or complicated type params
• Good test coverage (63%)

Limitations

• New, not proven in production.
• To do:
• Request timeouts
• chunked transfer-encoding for request bodies
• gzip
• brotli
• TLS
• automatically getting TLS certs via ACME
• Drop idle connections when approaching connection limit.
• Denial-of-Service mitigation: source throttling, minimum throughput
• Complete functional test suite
• Missing load tests
• Disk space usage limits

Examples

Complete examples: examples/.

Simple example:

use serde::Deserialize;
use serde_json::json;
use servlin::{
print_log_response,
socket_addr_127_0_0_1,
HttpServerBuilder,
Request,
Response
};
use servlin::reexport::{safina_executor, safina_timer};
use std::sync::Arc;
use temp_dir::TempDir;

struct State {}

fn hello(_state: Arc<State>, req: &Request) -> Result<Response, Response> {
#[derive(Deserialize)]
struct Input {
name: String,
}
let input: Input = req.json()?;
Ok(Response::json(200, json!({"message": format!("Hello, {}!", input.name)}))
.unwrap())
}

fn handle_req(state: Arc<State>, req: &Request) -> Result<Response, Response> {
match (req.method(), req.url().path()) {
("GET", "/ping") => Ok(Response::text(200, "ok")),
("POST", "/hello") => hello(state, req),
_ => Ok(Response::text(404, "Not found")),
}
}

let state = Arc::new(State {});
let request_handler = move |req: Request| {
print_log_response(&req, handle_req(state, &req))
};
let cache_dir = TempDir::new().unwrap();
safina_timer::start_timer_thread();
let executor = safina_executor::Executor::new(1, 9).unwrap();
# let permit = permit::Permit::new();
# let server_permit = permit.new_sub();
# std::thread::spawn(move || {
#     std::thread::sleep(std::time::Duration::from_millis(100));
#     drop(permit);
# });
executor.block_on(
HttpServerBuilder::new()
#       .permit(server_permit)
.listen_addr(socket_addr_127_0_0_1(8000))
.max_conns(1000)
.small_body_len(64 * 1024)
.receive_large_bodies(cache_dir.path())
.spawn_and_join(request_handler)
).unwrap();

Cargo Geiger Safety Report

Alternatives

See rust-webserver-comparison.md.

Changelog

• v0.1.0 - Renamed library to Servlin.

TO DO

• Fix limitations above
• Support HEAD responses that have Content-Length set and no body.
• Update rust-webserver-comparison.md
• Add missing data
• Add other servers from https://www.arewewebyet.org/topics/frameworks/
• Rearrange
• Generate geiger reports for each web server