JBoss Amputation

23 September 2008

java jboss jbossas rails

Since JBoss AS 5 is built on top of Microcontainer, it's effectively a network of beans just doing their respective jobs. You have already probably noticed that it ships with 3 included configurations: minimal, default, and all.

Unfortunately, they're awefully far apart along the spectrum of configuration options. The minimal configuration barely gets the container running, while the all configuration includes, well, everything. For most apps, it's safe to start with the default configuration. But default to who? It's the 80% case. But the 80% of the world who gets by with default, it still probably includes way more than they need. Of course, each user needs a different subset of that 80%.

Given that the MC is managing a graph, it seems like we should be able to actually perform a solve to determine what is or is not required. Or at least get a good idea. Bonus points if someone can then twiddle conf/, deploy/ and deployers/ to tidy things up.

Anyhow, for the jboss-as-rails project, I'm kicking it old-school, and going with default. I'm jamming it into git, and hopefully with some help, we can get it pared down to what we need.

The jboss-as-rails project is simply a configuration of AS that includes only what we need, along with the jboss-rails.deployer from the jboss-rails project (notice the subtle naming difference...).

Here's a picture to see how it'll all ultimately fit together.

The plugin will offer rake tasks for managing the included AS, deploying your app. I'll also produce an AS-free version of the plugin, assuming you want to manage your own AS separately.

And poke around jboss-as-rails, see what we can rip out.

JBoss on Rails

22 September 2008

java jboss jbossas rails ruby

Tomorrow is my first real status update call with my boss, Sacha Labourey. I've been anxious to deliver something, to prove I hadn't gone completely pudding-brained during my tenure as management.

This morning, it all finally came together in a pleasing fashion, causing me to hoot and holler loud enough to scare the cats and probably some cows.

I've just pushed an ugly-but-working deployer targeting JBoss-AS 5.0.0.CR2 (the latest and greatest!)

It's not very consumable at this point, as it's just a deployer, not a nice Rails plugin with a set of Rake tasks. Heck, it doesn't even undeploy yet.

But adding the deployer to your server's deployers/ directory allows you symlink live RAILS_ROOTs into your deploy/ directory, and be running on JBoss.

Live. In-situ. Edit your controllers or views as you like, and your changes are immediately reflected in the running instance. Just like with ./script/server. It does not even have to redeploy your app. The rails framework is handling the magic reloading.

It's taken me some time to dig through the innards of JBoss-Microcontainer, and a few false starts, but I finally figured out a super simple deployment process.

I'd previously been trying to manipulate a RAILS_ROOT into a synthetic Java WAR archive, and shoe-horn things around that. But I have the freedom to go lower than that, so the jboss-rails deployer just sets up a Catalina context appropriately, without regard to WEB-INF or other non-Rails stuff. There's no need for that cruft. Likewise, I can directly control and manipulate the classpath, so the RAILS_ROOT does not even have to have any JRuby bits in it.

The example application (src/test/ballast) is a virgin rails app with ActiveRecord disabled so I don't have to deal with database-driver gems just yet.

Once deployed, a Rails app looks like pretty much any other web-app. The jboss.rails.deployment domain contains deployment objects for each rails app. And jboss.web contains all the webby bits floating around.

I need to go back and remove the dead-end code I've left in my wake, and update the tests I'd disabled while in a coding flury (bad Bob!) I plan to put together an easy-to-consume plugin gem which contains an nicely-configured AS along with the jboss-rails deployer pre-installed, along with rake tasks to start/stop AS, and deploy your app. I'd also like to give clustering a whirl, and see what we can do.

It's been an excellent 3 weeks back as an engineer.