4 releases

0.7.1	Feb 3, 2024
0.7.0	Jan 20, 2024
0.6.2	Jan 20, 2024
0.6.1	Jan 20, 2024

#1642 in Web programming

AGPL-3.0

25KB
393 lines

rust-cgi

Easily create CGI (Common Gateway Interface) programs in Rust, based on http types.

This repository is a fork of the unmaintained https://github.com/amandasaurus/rust-cgi, which was published to crates.io as the cgi crate.

Installation & Usage

Cargo.toml:

[dependencies]
rust-cgi = "0.6"

Use the cgi_main! macro, with a function that takes a rust_cgi::Request and returns a rust_cgi::Response.

extern crate rust_cgi as cgi;

cgi::cgi_main! { |request: cgi::Request| -> cgi::Response {
     cgi::text_response(200, "Hello World")
} }

If your function returns a Result, you can use cgi_try_main!:

extern crate rust_cgi as cgi;

cgi::cgi_try_main! { |request: cgi::Request| -> Result<cgi::Response, String> {
    let greeting = std::fs::read_to_string("greeting.txt").map_err(|_| "Couldn't open file")?;

    Ok(cgi::text_response(200, greeting))
} }

It will parse and extract the CGI environmental variables, and the HTTP request body to create Request<u8>, call your function to create a response, and convert your Response into the correct format and print to stdout. If this program is not called as CGI (e.g. missing required environmental variables), it will gracefully fall back to using reasonable values (although the values themselves may be subject to change).

It is also possible to call the rust_cgi::handle function directly inside your main function:

extern crate rust_cgi as cgi;

fn main() { cgi::handle(|request: cgi::Request| -> cgi::Response {
    cgi::html_response(200, "<html><body><h1>Hello World!</h1></body></html>")
})}

Response Shortcuts

Several shortcuts create shortcuts easily:

rust_cgi:empty_response(status_code) - A HTTP Reponse with no body and that HTTP status code, e.g. return rust_igi::empty_response(404); to return a HTTP 404 Not Found.
rust_cgi::html_response(status_code, text) - Converts text to bytes (UTF8) and sends that as the body with that status_code and HTML Content-Type header.
rust_cgi::string_response(status_code, text) - Converts text to bytes (UTF8), and sends that as the body with that status_code but no Content-Type header.
rust_cgi::binary_response(status_code, content_type, blob) - Sends blob with that status code and the provided content type header.

Re-exports

http is re-exported, (as rust_cgi::http).

rust_cgi::Response/Request are http::Response<Vec<u8>>/Request<Vec<u8>>.

Running locally

Python provides a simple CGI webserver you can use to run your scripts. The binaries must be in a cgi-bin directory, so you'll need to create that directory and copy your binary into it. Given a project named example, run this in your project root directory (i.e. where Cargo.toml is):

mkdir cgi-bin
cargo build
cp target/debug/example cgi-bin/example
python3 -m http.server --cgi

and then open http://localhost:8000/cgi-bin/example.

MSRV policy

Currently the minimum supported Rust version (MSRV) is 1.51.0. MSRV increases will be kept to a minimum, and will always be accompanied with a minor version bump.

Why?

CGI is old, and easy to deploy. Just drop a binary in the right place, and Apache (or whatever) will serve it up. Rust is fast, so for simple things, there should be less downsides to spinning up a custom HTTP server.

Dependencies

~630KB
~10K SLoC