cgi
Easily create CGI (Common Gateway Interface) programs in Rust, based on
http types.
Installation & Usage
Cargo.toml:
[dependencies] cgi = \"0.6\"
Use the cgi_main! macro, with a function that takes a cgi::Request and returns a
cgi::Response.
extern crate 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 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 cgi::handle function directly inside your main function:
extern crate 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:
-
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. -
cgi::html_response(status_code, text)– Convertstextto bytes (UTF8) and
sends that as the body with thatstatus_codeand HTMLContent-Typeheader. -
cgi::string_response(status_code, text)– Convertstextto bytes (UTF8),
and sends that as the body with thatstatus_codebut noContent-Typeheader. -
cgi::binary_response(status_code, content_type, blob)– Sendsblobwith
that status code and the provided content type header.
Re-exports
http is re-exported, (as cgi::http).
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://*local*h*ost: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.
See also
- Rustdoc for this crate
- http crate
- RFC 3875 – The Common Gateway Interface (CGI) v1.1
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.
