Newbie’s information to server-side Swift utilizing the Hummingbird framework

Swift on the Server in 2023

Three years in the past I began to concentrate on Vapor, the preferred web-framework written in Swift, which served me very nicely through the years, however now it’s time to begin a brand new chapter in my life.

As I realized increasingly about how servers work I noticed that Vapor has it is personal execs and cons. The group modified so much in the course of the previous 3 years, some core members left and new folks began to keep up the framework. I additionally had some struggles with the default template engine (Leaf) and not too long ago I began to show away from the summary database layer (Fluent) too. One other ache level for me is the rising variety of dependencies, I barely use websockets & multipart-kit, however Vapor has these dependencies by default and you’ll’t eliminate them. 😢

Vapor has some very nice issues to supply, and for most people it is nonetheless going to be an amazing alternative for constructing backends for frontends (BFFs). For me, Vapor reached its limits and I wished to make use of one thing that feels a bit lighter. Somethings that’s modular, one thing that may be simply prolonged and matches my precise wants with out further (unused) package deal dependencies.

This shiny new factor is known as Hummingbird and it seems very promising. It was created by Adam Fowler who’s a member of the SSWG and in addition the principle creator of the Soto library (AWS Swift).

Hummingbird has a complete documentation accessible on-line and a pleasant instance repository containing varied demo apps written utilizing the Hummingbird Swift server framework. I consider that the perfect a part of the the framework is modularity & extensibility. By the best way, Hummingbird works with out Basis, but it surely has extensions for Basis objects, this can be a large plus for me, however possibly that is simply my private desire these days. Hummingbird may be prolonged simply, you will discover some very helpful extensions beneath the Hummingbird undertaking web page, lengthy story brief it really works with Fluent and it is comparatively simple to get together with it you probably have some Vapor information… 🤔

Getting began with Hummingbird

To start with, there is no such thing as a toolbox or command line utility to assist the kickoff course of, however you’ll be able to all the time obtain the examples repository and use one of many tasks as a place to begin. Alternatively you’ll be able to set every little thing up by hand, that is what we will do now. 🔨

With a purpose to construct a brand new utility utilizing the Hummingbird framework it’s best to create a brand new listing and initialize a brand new Swift package deal utilizing the next instructions:

mkdir server && cd $_
swift package deal init --type executable
open Bundle.swift

This can create a brand new Swift package deal and open the Bundle.swift file in Xcode. You should utilize your personal editor in the event you don’t love Xcode, however both approach you may have so as to add Hummingbird to your package deal manifest file as a dependency. We’ll setup an App goal for the appliance itself, and a Server goal for the principle executable, which can use the appliance and configure it as wanted.

import PackageDescription

let package deal = Bundle(
    identify: "server",
    platforms: [
        .macOS(.v10_15),
    ],
    dependencies: [
        .package(
            url: "https://github.com/hummingbird-project/hummingbird",
            from: "1.0.0"
        ),
        .package(
            url: "https://github.com/apple/swift-argument-parser",
            from: "1.0.0"
        ),
    ],
    targets: [
        .executableTarget(
            name: "Server",
            dependencies: [
                .product(
                    name: "ArgumentParser",
                    package: "swift-argument-parser"
                ),
                .target(name: "App"),
            ]
        ),
        .goal(
            identify: "App",
            dependencies: [
                .product(
                    name: "Hummingbird",
                    package: "hummingbird"
                ),
                .product(
                    name: "HummingbirdFoundation",
                    package: "hummingbird"
                ),
            ],
            swiftSettings: [
                .unsafeFlags(
                    ["-cross-module-optimization"],
                    .when(configuration: .launch)
                ),
            ]
        ),
        .testTarget(
            identify: "AppTests",
            dependencies: [
                .product(
                    name: "HummingbirdXCT",
                    package: "hummingbird"
                ),
                .target(name: "App"),
            ]
        ),
    ]
)

Please create the mandatory file and listing construction, as listed under, earlier than you proceed to the subsequent steps. It is vitally necessary to call issues as they seem, in any other case SPM will not work and the undertaking will not compile. Anyway, the undertaking construction is kind-of Vapor-like as you’ll be able to see. 💧

.
├── Bundle.resolved
├── Bundle.swift
├── README.md
├── Sources
│ ├── App
│ │ └── HBApplication+Configure.swift
│ └── Server
│     └── most important.swift
└── Assessments
    └── AppTests
        └── AppTests.swift

The subsequent step is to create the principle entry level for the appliance. For this objective Hummingbird makes use of the Swift Argument Parser library. Place the next contents into the principle.swift file:

import ArgumentParser
import Hummingbird
import App

struct HummingbirdCommand: ParsableCommand {

    @Possibility(identify: .shortAndLong)
    var hostname: String = "127.0.0.1"

    @Possibility(identify: .shortAndLong)
    var port: Int = 8080

    func run() throws {
        let app = HBApplication(
            configuration: .init(
                handle: .hostname(hostname, port: port),
                serverName: "Hummingbird"
            )
        )
        attempt app.configure()
        attempt app.begin()
        app.wait()
    }
}

HummingbirdCommand.most important()

The HummingbirdCommand has two choices, you’ll be able to setup a customized hostname and port by offering these values as command line choices (I will present it in a while), the appliance itself will setup the handle utilizing the enter after which it’s going to begin listening on the desired port.

The configure technique comes from the App goal, that is the place you’ll be able to customise your server occasion, register route handlers and stuff like that, identical to you’d do that in Vapor. The primary distinction is that Hummingbird makes use of the HB namespace, which is fairly useful, and the configure technique is written as an extension. Let’s write it and register a fundamental route handler. 🧩

import Hummingbird
import HummingbirdFoundation

public extension HBApplication {

    func configure() throws {

        router.get("/") { _ in
            "Good day, world!"
        }
    }
}

That is it. Now it’s best to be capable to run your server, you’ll be able to press the Play button in Xcode that’ll begin your utility or enter one of many following instructions into the Terminal utility:

# simply run the server
swift run Server

# customized hostname and port
swift run Server --port 3000
swift run Server --hostname 0.0.0.0 --port 3000

# brief model
swift run Server -p 3000
swift run Server -h 0.0.0.0 -p 3000

# set the log stage (https://github.com/apple/swift-log#log-levels)
LOG_LEVEL=discover swift run Server -p 3000

# make launch construct
swift construct -c launch

# copy launch construct to the native folder
cp .construct/launch/Server ./Server

# run the executable
LOG_LEVEL=discover ./Server -p 3000

You may set these values in Xcode too, simply click on on the server scheme and choose the Edit Scheme… menu merchandise. Just be sure you’re on the Run goal, displaying the Arguments tag. Merely provde the Arguments Handed On Launch choices to set a customized hostname or port and you’ll set the log stage by including a brand new merchandise into the Setting Variables part.

If you would like to unit take a look at your utility, I’ve acquired a excellent news for you. Hummingbird additionally comes with a pleasant utility instrument known as HummingbirdXCT, which you’ll be able to simply setup & use if you would like to run some assessments in opposition to your API. In our undertaking, merely alter the AppTests.swift file.

import Hummingbird
import HummingbirdXCT
import XCTest
@testable import App

ultimate class AppTests: XCTestCase {
    
    func testHelloWorld() throws {
        let app = HBApplication(testing: .stay)
        attempt app.configure()

        attempt app.XCTStart()
        defer { app.XCTStop() }

        attempt app.XCTExecute(uri: "/", technique: .GET) { response in
            XCTAssertEqual(response.standing, .okay)

            let expectation = "Good day, world!"
            let res = response.physique.map { String(buffer: $0) }
            XCTAssertEqual(res, expectation)
        }
    }
}

As a substitute of making the appliance from the principle entry level, we are able to arrange a brand new HBApplication occasion, import the App framework and name the configure technique on it. the XCT framework comes with a customized XCTStart and XCTStop technique, and you’ll execute HTTP requests utilizing the XCTExecute perform. The response is on the market in a completion block and it is attainable to look at the standing code and extract the physique utilizing a handy String initializer.

As you’ll be able to see Hummingbird is sort of much like Vapor, but it surely’s light-weight and you’ll nonetheless add these additional issues to your server when it’s wanted. Hummingbird seems like the subsequent iteration of Vapor. I actually do not know if Vapor 5, goes to repair the problems I am at present having with the framework or not, however I do not actually care, as a result of that launch will not occur anytime quickly.