Deploy of Clojure/Clojurescript application in production

Question

I'm playing with Clojure/ClojureScript and I'm writing a web application. Everything is fine while I'm using ring as a development server.

The question is what container should I use for production? Should I use ring for production as well? Should I use Tomcat? Is there a recommended way to deploy a Clojure application? Can you point me to some documentation regarding this aspect?

Thanks!

Answer 1

There is nothing inherently different about deploying a java servlet that was written in Java vs. Clojure and all the Clojure web libraries and frameworks produce compatable servlets so you have many deployment options.

We use netty to run our ring based web application to great effect in production simply by running "lein run" from a system service. Many others choose to use lein uberwar to produce a war file and host that on tomcat. The specific hosting mechanism seems less relevant than the deployment process. All the JavaScript files are served from a CDN. Immutant is also a fun and very Clojure oriented choice with a strong "enterprisy" feel to it.

What strikes me as most important is building a repeatable build, including deployment. Pallet is a great way to go though it's got a bit of a learning curve.

Answer 2

There are a few options.

First one is easy: Heroku. They have a free tier that is ample for deployment and testing. I won't go into further detail on this, but I decided not to use Heroku anymore.

Another common option is Amazon AWS. I gather most apps on AWS use lein-beanstalk [sorry, no citation here]. Lein-beanstalk has been out for quite a while and appears to be well-maintained. It is also maintained by the same person who maintains Compojure.

I use a VPS. I set up the linux build with Nginx and deploy with git. So, basically, my flow is create the site, compile to lein uberjar, then deploy. I know that some people can and do use the leiningen "lien ring server" cantation on their apps and use many other configurations, such as Maven, Tomcat, deployment with Vagrant, etc, but I just run java -jar myApp-xxxxx on the server and it works great.

As far as documentation, there does appear to be a dearth of documentation on Clojure deployment specifically. Sort of have to bang your head against the wall and figure it out if you want to go the VPS route the first time you do it. I found that almost none of my issues involved Clojure specifically.

Answer 3

In development I use:

lein ring server 

: then to compile it to a war file I use:

lein ring uberwar

: and just drop the resulting jar file into the Webapps directory and it works fine. I use Jetty by the way