Gatekeeper 👮

Gatekeeper is a middleware that restricts the number of requests from clients, based on their IP address (can be customized). It works by adding the clients identifier to the cache and count how many requests the clients can make during the Gatekeeper's defined lifespan and give back an HTTP 429(Too Many Requests) if the limit has been reached. The number of requests left will be reset when the defined timespan has been reached.

Please take into consideration that multiple clients can be using the same IP address. eg. public wifi

📦 Installation

Update your Package.swift dependencies:

.package(url: "https://github.com/nodes-vapor/gatekeeper.git", from: "4.0.0"),

as well as to your target (e.g. "App"):

targets: [
    .target(name: "App", dependencies: [..., "Gatekeeper", ...]),
    // ...
]

Getting started 🚀

Configuration

in configure.swift:

import Gatekeeper

// [...]

app.caches.use(.memory)
app.gatekeeper.config = .init(maxRequests: 10, per: .second)

Add to routes

You can add the GatekeeperMiddleware to specific routes or to all.

Specific routes in routes.swift:

let protectedRoutes = router.grouped(GatekeeperMiddleware())
protectedRoutes.get("protected/hello") { req in
    return "Protected Hello, World!"
}

For all requests in configure.swift:

// Register middleware
app.middlewares.use(GatekeeperMiddleware())

Customizing config

By default GatekeeperMiddleware uses app.gatekeeper.config as its configuration. However, you can pass a custom configuration to each GatekeeperMiddleware type via the initializer GatekeeperMiddleware(config:). This allows you to set configuration on a per-route basis.

Key Makers 🔑

By default Gatekeeper uses the client's hostname (IP address) to identify them. This can cause issues where multiple clients are connected from the same network. Therefore, you can customize how Gatekeeper should identify the client by using the GatekeeperKeyMaker protocol.

GatekeeperHostnameKeyMaker is used by default.

You can configure which key maker Gatekeeper should use in configure.swift:

app.gatekeeper.keyMakers.use(.hostname) // default

Custom key maker

This is an example of a key maker that uses the user's ID to identify them.

struct UserIDKeyMaker: GatekeeperKeyMaker {
    public func make(for req: Request) -> EventLoopFuture<String> {
        let userID = try req.auth.require(User.self).requireID()        
        return req.eventLoop.future("gatekeeper_" + userID.uuidString)
    }
}

extension Application.Gatekeeper.KeyMakers.Provider {
    public static var userID: Self {
        .init { app in
            app.gatekeeper.keyMakers.use { _ in UserIDKeyMaker() }
        }
    }
}

configure.swift:

app.gatekeeper.keyMakers.use(.userID)

Cache 🗄

Gatekeeper uses the same cache as configured by app.caches.use() from Vapor, by default. Therefore it is important to set up Vapor's cache if you're using this default behaviour. You can use an in-memory cache for Vapor like so:

configure.swift:

app.cache.use(.memory)

Custom cache

You can override which cache to use by creating your own type that conforms to the Cache protocol from Vapor. Use app.gatekeeper.caches.use() to configure which cache to use.

Credits 🏆

This package is developed and maintained by the Vapor team at Nodes. The package owner for this project is Christian. Special thanks goes to madsodgaard for his work on the Vapor 4 version!

License 📄

This package is open-sourced software licensed under the MIT license