migration.html

---
layout: doc
title: Migration from Jetty
---

<h2>Migrate from Ring Jetty adapter</h2>
<p>
  HTTP Kit is an almost drop-in
  replacement for the standard Ring Jetty adapter,
  just replace <code>run-jetty</code> with <code>run-server</code>.
</p>
<p>Few differences:</p>

  <h3 class="anchor" id="stop">Stop server programmatically</h3>
  {% highlight clojure %}
(let [jetty (run-jetty app options)]
  (.stop jetty))

(let [server (run-server app options)]
  ;; run-server returns a function that stops the server
  (server))
  {% endhighlight %}
  <h3 class="anchor" id="https">Configuring HTTPS</h3>
  <p>
    http-kit relies on reverse proxy (like <a href="http://wiki.nginx.org/HttpSslModule">Nginx</a>, <a href="http://redmine.lighttpd.net/projects/1/wiki/Docs_SSL">Lighthttpd</a>) to support HTTPS. <i>They also can be used as a <a href="server.html#deploy">reverse proxy to serve static files and compress content.</a></i>
  </p>
  <p>
    <a href="https://github.com/varnish/hitch">Hitch</a> is another option. It works well with websockets and long polling.
  </p>
  <p>Sample configration for Nginx: </p>

  {% highlight sh %}
server {
    listen 443 ssl;

    ssl on;
    ssl_certificate /etc/nginx/ssl/xxxxx_ssl.crt;
    ssl_certificate_key /etc/nginx/ssl/xxxx_ssl.key.nopasswd;

     location / {
        # http-kit listens on port 9090
        proxy_pass  http://127.0.0.1:9090/;
        proxy_set_header Host $http_host;
    }
}
  {% endhighlight %}
  </p>

  <h3 class="anchor" id="reload">Hot code reload (lein ring server)</h3>

    <p>Hot code reload is very handy, with the Jetty one you can do something like:</p>
    {% highlight sh %}
lein ring server  # https://github.com/weavejester/lein-ring
    {% endhighlight %}
    <p>lein-ring does not yet support http-kit, but
      <code>ring.middleware.reload</code> can be used as a workaround.</p>

{% highlight sh %}
lein run # start a server in :8080, hot code reload
{% endhighlight %}

    {% highlight clojure %}
;; project.clj
(defproject xxxx "1.0.1"
  :dependencies [[org.clojure/clojure "1.4.0"]
                 [compojure "1.1.5"]
                 [ring/ring-devel "1.1.8"]
                 [ring/ring-core "1.1.8"]
                 [http-kit "2.3.0"]]
  ; allow lein run to find a place to start
  :main clj_web.main)

;; src/clj_web/main.clj
(ns clj_web.main
  (:use [org.httpkit.server :only [run-server]])
  (:require [ring.middleware.reload :as reload]
            [compojure.handler :refer [site]]
            [compojure.route :as route]
            [compojure.core :refer [defroutes GET POST]]))

(defroutes all-routes
  (GET "/" [] "handling-page")
  (GET "/save" [] handler)     ;; websocket
  (route/not-found "<p>Page not found.</p>")) ;; all other, return 404

(defn in-dev? [&] true) ;; TODO read a config variable from command line, env, or file?

(defn -main [& args] ;; entry point, lein run will pick up and start from here
  (let [handler (if (in-dev? args)
                  (reload/wrap-reload (site #'all-routes)) ;; only reload when dev
                  (site all-routes))]
    (run-server handler {:port 8080})))
    {% endhighlight %}