How can jetty parameters be configured?

[elrob]

Hi Seratch 🙌

I have attempted to increase jetty max "requestHeaderSize" but failed until I created a custom JettyLauncher.

Failed attempts:

web.xml:

    <context-param>
        <param-name>org.eclipse.jetty.server.Request.maxHeaderSize</param-name>
        <param-value>16384</param-value>
    </context-param>
    <context-param>
        <param-name>org.eclipse.jetty.server.HttpConfiguration.headerBufferSize</param-name>
        <param-value>16384</param-value>
    </context-param>
    <context-param>
        <param-name>org.eclipse.jetty.server.HttpConfiguration.requestHeaderSize</param-name>
        <param-value>16384</param-value>
    </context-param>

java jar start command:

java -Dorg.eclipse.jetty.server.HttpConfiguration.requestHeaderSize=40000 -jar /app.jar

Eventually I got it working by basically copy-pasting skinny.standalone.JettyServer (https://github.com/skinny-framework/skinny-micro/blob/master/micro-server/src/main/scala/skinny/standalone/JettyServer.scala) and modifying it very slightly to configure the requestHeaderSize:

import org.eclipse.jetty.server.{HttpConnectionFactory, Server, ServerConnector}
import org.eclipse.jetty.servlet.DefaultServlet
import org.eclipse.jetty.webapp.WebAppContext
import skinny.micro.SkinnyListener
import skinny.standalone.JettyServer

import javax.servlet.ServletContextListener

object CustomJettyLauncher extends JettyServer {

  def main(args: Array[String]): Unit = {
    start()
    server.join()
  }

  override def start(): Unit = {
    refreshServer()
    logger.info(s"Starting Jetty server on port ${port}")
    val context = new WebAppContext()
    val contextPath = sys.env.get("SKINNY_PREFIX").orElse(getEnvVarOrSysProp("skinny.prefix")).getOrElse("/")
    context.setContextPath(contextPath)
    context.setWar({
      val domain = this.getClass.getProtectionDomain
      val location = domain.getCodeSource.getLocation
      location.toExternalForm
    })
    context.addEventListener(listener)
    context.addServlet(classOf[DefaultServlet], "/")
    server.setHandler(context)

    // Set the request header size
    server.getConnectors()(0).asInstanceOf[ServerConnector]
      .getConnectionFactory(classOf[HttpConnectionFactory])
      .getHttpConfiguration
      .setRequestHeaderSize(40000)

    server.start()
    logger.info(s"Started Jetty server on port ${port}")
  }

  private[this] var server: Server = _

  private[this] var listener: ServletContextListener = new SkinnyListener

  private[this] var _port: Int = {
    // PORT: Heroku default env variable
    Option(System.getenv("PORT")).map(_.toInt).getOrElse(8080)
  }

  private[this] def port: Int = {
    val port = sys.env.get("SKINNY_PORT").orElse(getEnvVarOrSysProp("skinny.port")).map(_.toInt).getOrElse(_port)
    port
  }

  private[this] def newServer(port: Int): Server = new Server(port)

  private[this] def refreshServer(): Unit = {
    if (server != null) {
      stop()
      server.destroy()
      server.synchronized {
        server = newServer(port)
      }
    } else {
      server = newServer(port)
    }
  }

  private[this] def getEnvVarOrSysProp(key: String): Option[String] = {
    sys.env.get(key).orElse(sys.props.get(key))
  }
}

Do you know of any cleaner way to do this?

[seratch]

Hi @elrob, thanks for writing in!

hmm, this is interesting. I had been assuming that Jetty automatically reflects all the system properties runtime but it does not work in the way when you build embedded web server like this library does.

I don't have any other ideas so far. I think that the lines of code you added are safe enough for any apps. So, if you send a pull request to this repo (no pressure!), I am happy to merge it and release a new version with the improvement! Perhaps, the hard-coded 40000 should be customizable. In my opinion, reading the standard system property can be the right way to go.

[elrob]

Thanks!
Yeah, I don't think my change is general enough.
If I could work out how to pick up general jetty config then I think it would make sense as a PR but I've tried that for an hour now and couldn't work out how to do it.