deps.edn + ring + compojure

deps.edn

{:deps {org.clojure/clojure {:mvn/version "1.10.0"}
        ring/ring-core {:mvn/version "1.7.1"}
        ring/ring-jetty-adapter {:mvn/version "1.7.1"}
        compojure {:mvn/version "1.6.1"}}}

light.clj

(ns light
  (:require [compojure.core :refer [routes GET]]
            [compojure.route :as route]
            [ring.adapter.jetty :refer [run-jetty]]))

(def handler
  (routes
    (GET "/" [] "<h1>Hello World</h1>")
    (route/not-found "<h1>Page not found</h1>")))

(defonce server (atom nil))

(defn start-webserver [& [{:keys [repl?]}]]
  (reset! server (run-jetty #'handler {:port 3000 :join? (not repl?)})))

(defn stop-webserver []
  (when @server
    (.stop @server)
    (reset! server nil)))

(defn -main [& _]
  (start-webserver))

(comment
  ; For starting server on repl
  (do
    (stop-webserver)
    (start-webserver {:repl? true}))
  )

; For starting server via shell
; $ clj -m light