Clojure API

A barebones Clojure REST API, for learning purposes.

For a more extensive Clojure API example see my Clojure CMS API.

The data endpoint uses the GiphyAPI.

Getting Started

Check your Java version, you need 1.6 or later:

java -v

Install Clojure by installing the Leiningen Build Tool

Clone this repo and start the server:

git clone git@github.com:peter/clojure-api.git
cd clojure-api
lein run

Test the API:

curl http://localhost:5000/data?q=cat

Deploying to Heroku

First install the Heroku Toolbelt and create a Heroku account. Then you can create an app and deploy:

$ heroku create
$ git push heroku master
$ heroku open

How to create an API from scratch with Leiningen

lein new app clojure-api
cd clojure-api

Edit project.clj and add ring-jetty-adapter to :dependencies:

[ring/ring-jetty-adapter "1.6.2"]

Also in project.clj, add these lines:

:min-lein-version "2.0.0"
:uberjar-name "clojure-api-standalone.jar"

Edit src/clojure_api/core.clj to read:

(ns clojure-api.core
  (:require [ring.adapter.jetty :as jetty]))

(defn app [request]
  {:status 200
   :headers {"Content-Type" "text/html"}
   :body "Welcome to Clojure API"})

(defn -main []
  (jetty/run-jetty app {
    :port (Integer. (get (System/getenv) "PORT" 5000))
    :join? false}))

Run the app locally:

lein run

Visit localhost:5000 in your browser.

To deploy to Heroku, make sure you have a Heroku account and the Heroku toolbelt installed. Then add a Procfile with this line:

web: java $JVM_OPTS -cp target/uberjar/clojure-api-standalone.jar clojure.main -m clojure-api.core

Check that your Procfile works locally:

lein uberjar
heroku local web

Add your app to git and deploy:

git init .
git add .
git commit -m "first commit"
heroku create
git push heroku master
heroku open
heroku logs --tail

Resources

Clojure on Heroku