Server

Creating a Server

A Server runs an Application. Every Application needs a Server, which is usually constructed via a ServerBuilder.

Using a ServerBuilder can be as simple as

val app: Application = Application.notFound

val builder = ServerBuilder.default.withApplication(app)

This uses the default settings (localhost and port 8080). There are builder methods that allow these to be changed.

Once the builder options have been set, calling the run method will construct a Server and immediately run it.

// If this wasn't just documentation we'd now have a server listening on port 8080.
builder.run()

A ServerBuilder can also be converted a Server using the build method.

val server: Server = builder.build

A Server can then be run, or converted to an IO[Unit] using toIO.

// Run the server immediately.
server.run()

// This IO can be run by an IOApp, for example
val io: IO[Unit] = server.toIO

Setting Server Options

Setting the server options, such as the port and host, are done by the builder methods on the ServerBuilder. Custom string contexts are provided for defining host and port. Concretely, this means writing code like

ServerBuilder.default.withPort(port"4000")
// Host can be a name or an IP address
ServerBuilder.default.withHost(host"127.0.0.1")
ServerBuilder.default.withHost(host"localhost")

Routing→