Template: worker-rust

A template for kick starting a Cloudflare worker project using workers-rs.

This template is designed for compiling Rust to WebAssembly and publishing the resulting worker to Cloudflare's edge infrastructure.

Setup

To create a my-project directory using this template, run:

$ npx wrangler generate my-project https://github.com/cloudflare/workers-sdk/templates/experimental/worker-rust
# or
$ yarn wrangler generate my-project https://github.com/cloudflare/workers-sdk/templates/experimental/worker-rust
# or
$ pnpm wrangler generate my-project https://github.com/cloudflare/workers-sdk/templates/experimental/worker-rust

Wrangler

Wrangler is used to develop, deploy, and configure your Worker via CLI.

Further documentation for Wrangler can be found here.

Usage

This template starts you off with a src/lib.rs file, acting as an entrypoint for requests hitting your Worker. Feel free to add more code in this file, or create Rust modules anywhere else for this project to use.

With wrangler, you can build, test, and deploy your Worker with the following commands:

# run your Worker in an ideal development workflow (with a local server, file watcher & more)
$ npm run dev

# deploy your Worker globally to the Cloudflare network (update your wrangler.toml file for configuration)
$ npm run deploy

Read the latest worker crate documentation here: https://docs.rs/worker

Advanced Example

As this template comprises only the essential setup, we recommend considering our advanced example to leverage its additional functionalities. The advanced example showcases the creation of multiple routes, logging of requests, retrieval of field data from a form, and other features that may prove useful to your project.
The following example has been taken from: workers-rs. You can learn more about how to use workers with rust by going there.

use worker::*;

#[event(fetch)]
pub async fn main(req: Request, env: Env, _ctx: worker::Context) -> Result<Response> {
    console_log!(
        "{} {}, located at: {:?}, within: {}",
        req.method().to_string(),
        req.path(),
        req.cf().coordinates().unwrap_or_default(),
        req.cf().region().unwrap_or("unknown region".into())
    );

    if !matches!(req.method(), Method::Post) {
        return Response::error("Method Not Allowed", 405);
    }

    if let Some(file) = req.form_data().await?.get("file") {
        return match file {
            FormEntry::File(buf) => {
                Response::ok(&format!("size = {}", buf.bytes().await?.len()))
            }
            _ => Response::error("`file` part of POST form must be a file", 400),
        };
    }

    Response::error("Bad Request", 400)
}

WebAssembly

workers-rs (the Rust SDK for Cloudflare Workers used in this template) is meant to be executed as compiled WebAssembly, and as such so must all the code you write and depend upon. All crates and modules used in Rust-based Workers projects have to compile to the wasm32-unknown-unknown triple.

Read more about this on the workers-rs project README.

Issues

If you have any problems with the worker crate, please open an issue on the upstream project issue tracker on the workers-rs repository.