Canteen

Description

Canteen is the first project that I'm implementing in Rust. It's a clone of Flask, my very favorite Python web framework. There is code for an example implementation in the canteen-impl repository.

Usage

It's by no means complete, but I'm working on it, and it's now available on crates.io! To install and check it out, add the following to your Cargo.toml:

[dependencies]
canteen = "0.5"

The principle behind Canteen is simple -- handler functions are defined as simple Rust functions that take a Request and return a Response. Handlers are then attached to one or more routes and HTTP methods/verbs. Routes are specified using a simple syntax that lets you define variables within them; variables that can then be extracted to perform various operations. Currently, the following variable types can be used:

• <str:name> will match anything inside a path segment, returns a String
• <int:name> will return a signed integer (i32) from a path segment
  • ex: cnt.add_route("/api/foo/<int:foo_id>", &[Method::Get], my_handler) will match "/api/foo/123" but not "/api/foo/123.34" or "/api/foo/bar"
• <uint:name> will return an unsigned integer (u32)
• <float:name> does the same thing as the int parameter definition, but matches numbers with decimal points and returns an f32
• <path:name> will greedily take all path data contained, returns a String
  • ex: cnt.add_route("/static/<path:name>", &[Method::Get], utils::static_file) will serve anything in the /static/ directory as a file

After the handlers are attached to routes, the next step is to simply start the server. Any time a request is received, it is dispatched with the associated handler to a threadpool worker. The worker notifies the parent process when it's finished, and then the response is transmitted back to the client. Pretty straightforward stuff!

Example

extern crate canteen;

use canteen::*;
use canteen::utils;

fn hello_handler(req: &Request) -> Response {
    let mut res = Response::new();

    res.set_status(200);
    res.set_content_type("text/plain");
    res.append("Hello, world!");

    res
}

fn double_handler(req: &Request) -> Response {
    let to_dbl: i32 = req.get("to_dbl");

    /* simpler response generation syntax */
    utils::make_response(format!("{}", to_dbl * 2), "text/plain", 200)
}

fn main() {
    let cnt = Canteen::new();

    // bind to the listening address
    cnt.bind(("127.0.0.1", 8080));

    // set the default route handler to show a 404 message
    cnt.set_default(utils::err_404);

    // respond to requests to / with "Hello, world!"
    cnt.add_route("/", &[Method::Get], hello_handler);

    // pull a variable from the path and do something with it
    cnt.add_route("/double/<int:to_dbl>", &[Method::Get], double_handler);

    // serve raw files from the /static/ directory
    cnt.add_route("/static/<path:path>", &[Method::Get], utils::static_file);

    cnt.run();
}