Question

I’m just looking to run a ring server on bootup. I’m using ubuntu 12.04 and was wondering how other people deployed their apps.

Answer 1

The upstart cookbook was pretty daunting… but it was easier than I thought. The upstart script is actually quite straight forward to write.

Here are the steps I took to get it working:

(1) In your project.clj, put a :main keyword pointing to the class to run. eg:

(defproject lapis "0.1.0-SNAPSHOT"
  :dependencies ...
  ... rest of file ...
  :main lapis.app)

(2) Then in the class, add a :gen-class directive to the namespace as well as a -main function:

(ns lapis.app
  (:gen-class)
  (:use ....)
  (:require...))

(defn -main [&args]
  ......)

(3) Use lein uberjar in to generate the jar file:

$ lein uberjar
> Including fs-1.3.2.jar
> Including jetty-io-7.6.1.v20120215.jar
> ........
> Including jetty-continuation-7.6.1.v20120215.jar

> Created /home/example/lapis/target/lapis-0.1.0-SNAPSHOT-standalone.jar

(4) Make sure that the .jar file runs:

$ java -jar target/lapis-0.1.0-SNAPSHOT-standalone.jar

and also test it outside of your project directory because there may be problems with files in your resources directory that you may not be aware of:

$ cd ~
$ java -jar /home/example/lapis/target/lapis-0.1.0-SNAPSHOT-standalone.jar

(5) If everything works, the upstart file is placed in /etc/init/.conf.

My script was 5 lines:

$ cat /etc/init/lapis.conf
> -------------
> start on started

> script
>  exec /usr/bin/java -jar  /home/example/lapis/target/lapis-0.1.0-SNAPSHOT-standalone.jar >> /var/log/lapis/lapis.log 2>&1
> end script
> --------------

(6) Test to see if the service works:

$ sudo start lapis
>  lapis start/running, process 2543

$ sudo stop lapis
> lapis stop/waiting