Create a simple Hello World application

This quick tutorial will take you through creating a simple Hello World example with Kitura.

Step 1: Create project

First create a directory for our project, which will also serve as the project's name:

mkdir HelloKitura && cd HelloKitura

Initialize the directory as a Swift project:

swift package init --type executable

Swift Package Manager (SPM) creates a Swift project stub. All we need to do is add our project dependencies, like Kitura, to the project.

Step 2: Add Kitura to our dependencies

To add Kitura to our dependencies we need to edit the Package.swift file.

Open Package.swift in your default text editor:

open Package.swift

Add Kitura to our dependencies so the Package.swift file looks like this:

// swift-tools-version:5.0
import PackageDescription

let package = Package(
    name: "HelloKitura",
    dependencies: [
        .package(url: "https://github.com/Kitura/Kitura", from: "2.8.0")
    ],
    targets: [
        .target(
            name: "HelloKitura",
            dependencies: ["Kitura"]),
        .testTarget(
            name: "HelloKituraTests",
            dependencies: ["HelloKitura"]),
    ]
)

Now we can build the project to pull down our new dependency:

swift build

Step 3: Add the server code

Open main.swift in our text editor:

open Sources/HelloKitura/main.swift

Replace the contents of the file with the following code:

import Kitura

let router = Router()

router.get("/") { request, response, next in
    response.send("Hello world!")
    next()
}

Kitura.addHTTPServer(onPort: 8080, with: router)
Kitura.run()

The code above is the simplest Kitura application we can create. This application starts a server and listens on port 8080 for connections. The application responds with “Hello World!” when requests are made to the root URL (/).

Step 4: Start the server

Run the project:

swift run

Open your web browser at localhost:8080.

You should see the following in your browser:

"Hello, World!"

Congratulations! You have just created your first server-side Swift application using Kitura.

Next steps

In this simple Kitura application all of our Swift code is contained in a single main.swift file.

In practice it's preferable to structure your project code in more than one file. To generate scaffolding for a more complex application checkout our Create a Server Guide and then explore our other guides!