Ruby Tutorials

It’s been a looong time but this I want to share with you.
For a project I’m currently working on we needed something really really fast. Rails with Ruby MRI was out of the question so we went for JRuby and Merb. This particular piece of the project is ideally suited for Merb as we are using it as a backend system (webservice) only.

So you want JRuby because it is blazingly fast (at least compared to MRI)? Fine. But how to deploy the bugger? We quickly decided on Glassfish an open source application server made and maintained by Sun. Moreover this lovely server had a gem which you can use to fire up a Glassfish server. Easy as pie and within no time at all we were developing our Merb app on Glassfish.

I was charged with the task to deploy the app to the server and that’s when the trouble began. First off I installed JRuby 1.1.5 (in /usr/local/jruby) and installed the Glassfish gem (v0.9.0). I had no idea how to monitor and fire up the gem but that was for later. Installed the glassfish and merb-core (!) gem ($ jruby -S gem install glassfish merb-core). Don’t install Merb! This won’t work as it depends on a gem which tries to build native extensions.

Still manually copying over the source of our app I ran the glassfish command only to be greeted with an Activator error. Took me a while to figure out but this appears to be a proper bug. The maintainer is aware of the issue and will fix it in the 0.9.1 release of the gem. No good for me so onward.

If the gem doesn’t work than the true Glassfish server might do the trick. I come from a Java background but have been developing Rails/Ruby now for over a year and I quite forgot how incredibly verbose the Java world is. After reading for an odd couple of hours or so. I went for the installer of the Glassfish v3 prelude. The v3 release does not require you to package up your app in a WAR file which sounded very good. Unfortunately the installer died with some unclear error messages and I just downloaded the zip and unpacked it in /usr/local/glassfish.

More dark clouds ahead! I have no idea how this stuff works and although there are a couple of Rails examples non worked for our Merb app. :S Starting the server with jruby was already a challenge, in the end

java -J-server -Xmx256m -Djruby.home=/usr/local/jruby-1.1.5/ -jar /usr/local/glassfishv3-prelude/glassfish/modules/glassfish.jar

did the trick. But how to get Glassfish to accept my ‘exploded’ (eg non WAR/EAR) Merb app? I still have no idea. Enter Warbler.

This charming little gem turns a Rails, Merb or Rack app into a WAR file ready to be deployed. I’ll leave out all the errors and just to it. First off edit the config.rb file of the warbler gem (found in /usr/local/jruby-1.1.5/lib/ruby/gems/1.8/gems/warbler-0.9.11/lib/warbler/), got to the auto_detect_merb method and change the line:

@gems[”merb”] = Merb::VERSION

to:

@gems[”merb-core”] = Merb::VERSION

This will enable warbler to find the correct gem. Installing the gem ‘merb’ was not an option for JRuby!

Second edit the merb-core gemspec (found in /usr/local/jruby-1.1.5/lib/ruby/gems/1.8/specifications) and find all references to webrat and remove them. Webrat depends on Nokogiri which in turn has native dependencies… etc etc.

Third replace the jruby and jruby-rack version in /usr/local/jruby-1.1.5/lib/ruby/gems/1.8/gems/warbler-0.9.11/lib with the hottest flavours (JRuby-Rack: http://kenai.com/downloads/jruby-rack/, JRuby: http://dist.codehaus.org/jruby/)

We are now ready for WAR.

Config the war file!

$ jruby -S warble config


Edit the config/warble.rb file. Remove the ‘vendor’ and ‘tmp’ directory from the config.dirs directive. LEAVE all references to config.gem alone. This does not work as expected config.gem -= “rails” does not remove the rails dependency. On the contrary. The config.webxml.booter needs to say :merb. Save-close-etc.

Create the war file!

$ jruby -S warble war


Tell the now running Glassfish server to deploy it with

$ /urs/local/glassfish/bin/asadmin deploy your_app.war


The server is running on port localhost:8080/your_app
May this help.

This entry was posted on Wednesday, December 3rd, 2008 at 4:58 pm and is filed under development. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.