Immutant on OpenShift

Here is a quick way to try out your Leiningen-based Clojure application running in Immutant on OpenShift.

By default, this quickstart will install the latest incremental version of Immutant. You can specify a different version by tweaking .openshift/action_hooks/pre_start_jbossas-7, but any build older than incremental 607 won't work. ;-)

One particularly nice thing about OpenShift is that it provides simple ssh port forwarding, so you can configure your app to start either a Swank or nREPL server and connect to it via an ssh tunnel. The only stipulation is that the port you specify be between 15000-35530. So in your project.clj, you might add:

:immutant {:nrepl-port 24005}

You can then run rhc port-forward -a yourapp to setup your tunnel. These and other :immutant options can be specified in the deployment descriptor as well; see deployments/your-clojure-application.clj.

Running on OpenShift

Create an account at http://openshift.redhat.com/

Create a jbossas-7 application

rhc app create -a yourapp -t jbossas-7

Remove the sample app provided by the jbossas-7 cartridge

cd yourapp
rm -rf pom.xml src

Add this upstream repo

git remote add quickstart -m master git://github.com/openshift-quickstart/immutant-quickstart.git
git pull --no-commit -s recursive -X theirs quickstart master

Then add, commit, and push your changes

git add -A .
git commit -m "Add Immutant modules and setup Clojure project"
git push

That's it! The first build will take a minute or two, even after the push completes, so be patient. You should ssh to your app and run tail_all so you'll have something to watch while your app deploys.

When you see Deployed "your-clojure-application.clj" in the log, point a browser at the following link (adjusted for your namespace) and you should see a friendly welcome:

http://yourapp-$namespace.rhcloud.com

Drop in to the #immutant IRC channel on freenode.net if you have any questions.