rustless 0.3.0

Rustless is a REST-like API micro-framework for Rust.
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Table of Contents

What is Rustless?

Build Status

Rustless is a REST-like API micro-framework for Rust. It's designed to provide a simple DSL to easily develop RESTful APIs on top of the Iron web framework. It has built-in support for common conventions, including multiple formats, subdomain/prefix restriction, content negotiation, versioning and much more.

Rustless in a port of Grape library from Ruby world. Based on hyper - an HTTP library for Rust.

Like Rust itself, Rustless is still in the early stages of development, so don't be surprised if APIs change and things break. If something's not working properly, file an issue or submit a pull request!

# Cargo.toml
[dependencies.rustless]
git = "https://github.com/rustless/rustless"

API docs

See also

Basic Usage

Below is a simple example showing some of the more common features of Rustless.

#![feature(phase)]

#[phase(plugin)]
extern crate rustless;
extern crate rustless;
extern crate hyper;
extern crate serialize;

use std::io::net::ip::Ipv4Addr;
use serialize::json::{JsonObject, ToJson};
use rustless::{
    Server, Application, Valico, Api, Client, Nesting, 
    HandleResult, HandleSuccessResult, AcceptHeader
};

fn main() {

    let api = box Api::build(|api| {
        // Specify API version
        api.version("v1", AcceptHeader("chat"));
        api.prefix("api");

        // Create API for chats
        let chats_api = box Api::build(|chats_api| {

            chats_api.after(|client, _params| {
                client.set_status(hyper::status::NotFound);
                Ok(())
            });

            // Add namespace
            chats_api.namespace("chats/:id", |chat_ns| {
                
                // Valico settings for this namespace
                chat_ns.params(|params| { 
                    params.req_typed("id", Valico::u64())
                });

                // Create endpoint for POST /chats/:id/users/:user_id
                chat_ns.post("users/:user_id", |endpoint| {
                
                    // Add description
                    endpoint.desc("Update user");

                    // Valico settings for endpoint params
                    endpoint.params(|params| { 
                        params.req_typed("user_id", Valico::u64());
                        params.req_typed("name", Valico::string())
                    });

                    endpoint.handle(|client, params| {
                        client.json(&params.to_json())
                    })
                });

            });
        });

        api.mount(chats_api);
    });

    let mut app = Application::new(api);

    Iron::new(app).listen("localhost:4000").unwrap();
    println!("On 4000");

    println!("Rustless server started!");
}

Mounting

In Rustless you can use three core entities to build your RESTful app: Api, Namespace and Endpoint.

  • Api can mount Api, Namespace and Endpoint
  • Namespace can mount Api, Namespace and Endpoint
Api::build(|api| {

    // Api inside Api example
    api.mount(Api::build(|nested_api| {

        // Endpoint definition
        nested_api.get("nested_info", |endpoint| {
            // endpoint.params(|params| {});
            // endpoint.desc("Some description");

            // Endpoint handler
            endpoint.handle(|client, _params| {
                client.text("Some usefull info".to_string())
            })
        });

    }))

    // The namespace method has a number of aliases, including: group, 
    // resource, resources, and segment. Use whichever reads the best 
    // for your API.
    api.namespace("ns1", |ns1| {
        ns1.group("ns2", |ns2| {
            ns2.resource("ns3", |ns3| {
                ns3.resources("ns4", |ns4| {
                    ns4.segment("ns5", |ns5| {
                        // ...
                    );
                })
            })
        })
    })
})

Parameters validation and coercion

You can define validations and coercion options for your parameters using a DSL block inside Endpoint and Namespace definition. See Valico for more info about things you can do.

api.get("users/:user_id/messages/:message_id", |endpoint| {
    endpoint.params(|params| {
        params.req_typed("user_id", Valico::u64());
        params.req_typed("message_id", Valico::u64());
    });

    // ...
})

Query strings

Rustless is intergated with queryst to allow smart query-string parsing end decoding (even with nesting, like foo[0][a]=a&foo[0][b]=b&foo[1][a]=aa&foo[1][b]=bb). See queryst for more info.

API versioning

There are three strategies in which clients can reach your API's endpoints:

  • Path
  • AcceptHeader
  • Param

Path versioning strategy

api.version("v1", Path);

Using this versioning strategy, clients should pass the desired version in the URL.

curl -H http://localhost:3000/v1/chats/

Header versioning strategy

api.version("v1", AcceptHeader("chat"));

Using this versioning strategy, clients should pass the desired version in the HTTP Accept head.

curl -H Accept:application/vnd.chat.v1+json http://localhost:3000/chats

Accept version format is the same as Github (uses)[https://developer.github.com/v3/media/].

Param versioning strategy

api.version("v1", Param("ver"));

Using this versioning strategy, clients should pass the desired version as a request parameter in the URL query.

curl -H http://localhost:9292/statuses/public_timeline?ver=v1

Respond with custom HTTP Status Code

By default Rustless returns a 200 status code for GET-Requests and 201 for POST-Requests. You can use status and set_status to query and set the actual HTTP Status Code

client.set_status(NotFound);

Use parameters

Request parameters are available through the params: JsonObject inside Endpoint handlers and all callbacks. This includes GET, POST and PUT parameters, along with any named parameters you specify in your route strings.

The request:

curl -d '{"text": "hello from echo"}' 'http://localhost:3000/echo' -H Content-Type:application/json -v

The Rustless endpoint:

api.post("", |endpoint| {
    endpoint.handle(|client, params| {
        client.json(params)
    })
});

In the case of conflict between either of:

  • route string parameters
  • GET, POST and PUT parameters
  • the contents of the request body on POST and PUT

route string parameters will have precedence.

Redirecting

You can redirect to a new url temporarily (302) or permanently (301).

client.redirect("http://google.com");
client.redirect_permanent("http://google.com");

Errors firing

You can abort the execution of an API method by raising errors with error.

Define your error like this:

use rustless::errors::{Error, ErrorRefExt};

#[deriving(Show)]
pub struct UnauthorizedError;

impl std::error::Error for UnauthorizedError {
    fn description(&self) -> &str {
        return "UnauthorizedError";
    }
}

And then throw:

client.error(UnauthorizedError);

Errors handling

By default Rustless wil respond all errors with status::InternalServerError.

Rustless can be told to rescue specific errors and return them in the custom API format.

api.error_formatter(|err, _media| {
    match err.downcast::<UnauthorizedError>() {
        Some(_) => {
            return Some(Response::from_string(StatusCode::Unauthorized, "Please provide correct `token` parameter".to_string()))
        },
        None => None
    }
});

Before and After callbacks

Blocks can be executed before or after every API call, using before, after, before_validation and after_validation.

Before and after callbacks execute in the following order:

  1. before
  2. before_validation
  3. validations
  4. after_validation
  5. the API call
  6. after

Steps 4, 5 and 6 only happen if validation succeeds.

The block applies to every API call within and below the current nesting level.

Secure API example

Api::build(|api| {
    api.prefix("api");
    api.version("v1", Versioning::Path);

    api.error_formatter(|err, _media| {
        match err.downcast::<UnauthorizedError>() {
            Some(_) => {
                return Some(Response::from_string(StatusCode::Unauthorized, "Please provide correct `token` parameter".to_string()))
            },
            None => None
        }
    });

    api.namespace("admin", |admin_ns| {

        admin_ns.params(|params| {
            params.req_typed("token", Valico::string())
        });

        // Using after_validation callback to check token
        admin_ns.after_validation(|&: _client, params| {

            match params.get("token") {
                // We can unwrap() safely because token in validated already
                Some(token) => if token.as_string().unwrap().as_slice() == "password1" { return Ok(()) },
                None => ()
            }

            // Fire error from callback is token is wrong
            return Err(Box::new(UnauthorizedError) as Box<Error>)

        });

        // This `/api/admin/server_status` endpoint is secure now
        admin_ns.get("server_status", |endpoint| {
            endpoint.handle(|client, _params| {
                {
                    let cookies = client.request.cookies();
                    let signed_cookies = cookies.signed();

                    let user_cookie = Cookie::new("session".to_string(), "verified".to_string());
                    signed_cookies.add(user_cookie);
                }

                client.text("Everything is OK".to_string())  
            })
        });
    })
})

JSON responses

Rustless includes JsonWay library to offer both complex JSON building DSL and configurable serializers for your objects. See API docs for details.

Also feel free to use any other serialization library you want.

Swagger 2.0

Rustless has a basic implementation of Swagger 2.0 specification. It is not fully complete and in future we need to implement:

  • JSON Schema support (when some appropriate JSON Schema library will appear);
  • Security parts of the specification;

But now you can already use Swagger 2.0:

let mut app = rustless::Application::new(rustless::Api::build(|api| {
    // ...

    api.mount(swagger::create_api("api-docs"));

    // ... 
}))

swagger::enable(&mut app, swagger::Spec {
    info: swagger::Info {
        title: "Example API".to_string(),
        description: Some("Simple API to demonstration".to_string()),
        contact: Some(swagger::Contact {
            name: "Stanislav Panferov".to_string(),
            url: Some("http://panferov.me".to_string()),
            ..std::default::Default::default()
        }),
        license: Some(swagger::License {
            name: "MIT".to_string(),
            url: "http://opensource.org/licenses/MIT".to_string()
        }),
        ..std::default::Default::default()
    },
    host: "localhost:4000".to_string(),
    ..std::default::Default::default()
});

After that you can use /api-docs path in Swagger UI to render your API structure.