Starting with a minimalistic webapp.

helloweb_core.clj

(ns helloweb.core
   (:require [org.httpkit.server :as httpkit]
             [compojure.handler :as handler]
             [ring.util.response :refer [redirect response]]
             [ring.util.codec :refer [url-encode]]
             [hiccup.page :refer [html5]]
             [hiccup.form :as f]
             [compojure.core :refer [defroutes GET POST]]
             [compojure.route :as route]))


;; -------------------------------------------------------------------
;; your first webapp (yes, only a function)

(defn app
  [request]
  {:status 200
   :body request})


;; -------------------------------------------------------------------
;; http server start/stop infrastructure

(defonce http-server (atom nil))

(defn stop!
  "Stops the http server if started."
  []
  (when-let [shutdown-fn @http-server]
    (shutdown-fn)
    (reset! http-server nil)
    :stopped))


(defn start!
  "Starts http server, which is reachable on http://localhost:8080"
  []
  (stop!)
  (reset! http-server (httpkit/run-server (handler/site #'app) {:port 8080}))
  :started) 

project.clj

(defproject helloweb "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url "http://example.com/FIXME"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}
  :dependencies [[org.clojure/clojure "1.6.0"]
                 [http-kit "2.1.19"]
                 [hiccup "1.0.5"]
                 [ring "1.3.1"]
                 [compojure "1.2.0"]])