okapi

OpenAPI (AKA Swagger) document generation for Rust projects

Work in progress!

Basic Usage

#![feature(proc_macro_hygiene, decl_macro)]

#[macro_use]
extern crate rocket;
#[macro_use]
extern crate rocket_okapi;

use rocket_contrib::json::Json;
use rocket_okapi::swagger_ui::make_swagger_ui;
use serde::{Deserialize, Serialize};
use schemars::JsonSchema;

// Derive JsonSchema for and request/response models
#[derive(Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "camelCase")]
struct User {
    user_id: u64,
    username: String,
    #[serde(default)]
    email: Option<String>,
}

// Add #[openapi] attribute to your routes
#[openapi]
#[get("/user/<id>")]
fn get_user(id: u64) -> Option<Json<User>> {
    Some(Json(User {
        user_id: id,
        username: "bob".to_owned(),
        email: None,
    }))
}

// You can skip routes that you don't want to include in the openapi doc
#[openapi(skip)]
#[get("/hidden")]
fn hidden() -> Json<&'static str> {
    Json("Hidden from swagger!")
}

pub fn make_rocket() -> rocket::Rocket {
    rocket::ignite()
        // routes_with_openapi![...] will host the openapi document at openapi.json
        .mount(
            "/",
            routes_with_openapi![get_user, hidden],
        )
        // You can optionally host swagger-ui too
        .mount(
            "/swagger-ui/",
            make_swagger_ui(&SwaggerUIConfig {
                url: "../openapi.json".to_owned(),
                ..Default::default()
            }),
        )
}

TODO

• Tests
• Documentation
• Benchmark/optimise memory usage and allocations
  • Note to self: https://crates.io/crates/graphannis-malloc_size_of looks useful
• Implement OpenApiFrom___/OpenApiResponder for more rocket/rocket-contrib types
• Allow customizing openapi generation settings, e.g.
  • custom json schema generation settings
  • change path the document is hosted at