Lambdaserve - A minimal web server platform for Scala on Jetty

Lambdaserve is a minimalistic web server platform for Scala on Jetty. It is designed to be simple and easy to use, and to provide a solid foundation for building small to medium web applications in Scala.

Similarities

Scalatra, Django, Spring Boot (the web parts) provided some inspiration for the approach and features.

Scalatra for the route definitions. Django for the regex-based path definitions. Spring boot for the easy extraction of data from the requests.

Features

Simple route definitions

Routes are defined using a simple DSL that is similar to Scalatra's route definitions.

import net.lambdaserve.core.Router
import net.lambdaserve.core.http.*
import net.lambdaserve.core.http.Util.HttpMethod
import net.lambdaserve.server.jetty.Server
import org.eclipse.jetty.server.{Server, ServerConnector}
import scala.io.StdIn

import HttpMethod.*

val routes = List(
  GET -> "/hello".r -> { req =>
    Response.Ok("Hello, world!")
  },
)

val router = Router.make(routes)

val jetty = Server.makeServer(
  "localhost",
  0,
  router,
  staticPaths = List("classpath:static-files"),
  staticPrefix = Some("/static")
)

val openPorts = jetty.getConnectors
  .collect { case s: ServerConnector => s.getLocalPort }
  .mkString(",")

StdIn.readLine(s"Listening on port(s) $openPorts, awaiting exit...")
jetty.stop()

Easy extraction of data from requests

Easy to use and extend

Minimal dependencies

With everything included the dependencies are:

• Jetty
• jsoniter for JSON (de)serialization
• slf4j and I recommend Scribe for logging
• Tyrian or Scalatags

This brings the example application to a total size of 12MB.

No reflection

We use Magnolia macros for some typeclases.