Deploying Rails to Tomcat as a WAR with JRuby

tutorial, ruby, software development

Assumptions

• You are experienced with Java and have at least dabbled around with Ruby on Rails.
• These steps worked for me on a Mac OS X 1.0.4.9 system
• I've walked through the steps 3 times from scratch, but your mileage may still vary.

Install and Configure JRuby

First step download install JRuby. You can get it at:

• http://dist.codehaus.org/jruby/

After pulling down the tarball, jruby-bin-1.0.0RC2.tar.gz, I unpacked it and installed at:

• /Applications/jruby1.0.2RC

Next, add the environment variable JRUBY_HOME to point to /Applications/jruby1.0.2RC. I added it to my .bash_profile since I'm running the bash shell by default on Mac OS X:


# JRuby
export JRUBY_HOME=/Applications/jruby1.0.0RC2


Since I don't want to take out my normal Ruby C install I just export it in front of the path just for this terminal session:


export PATH=$JRUBY_HOME/bin:$PATH


Double check that JRuby is setup:

jruby --version

This should return something like:

ruby 1.8.5 (2007-05-16 rev 3672) [i386-jruby1.0.0RC2]

Test With A Simple JRuby App

Go ahead and setup a directory for your JRuby apps:


cd ~
mkdir jruby_stuff
cd jruby_stuff
mate test_java.rb


The last step assumes your using textmate. You can replace it with any vi or any other editor you want.

Write a small JRuby app and save it:

Go ahead and run the simple ruby script and test the java integration of JRuby:


jruby test_java.rb


Should see:


Ruby
+
Java
=
JRuby


Rails Setup

Run:

gem install rails -y --no-ri --no-rdoc


This should take about a minute. There are lots of notes on how ri and Rdoc take a long time to run right now, but it wasn't too bad, about 5 minutes on a duo core Macbook Pro, but you can keep the two switches and save a little time.

The next step is a bit odd. For some reason the rails and rake files don't get installed as executable. You have to make them executable and then pick up the changes using the bash hash command.


chmod 775 $JRUBY_HOME/bin/rails
chmod 775 $JRUBY_HOME/bin/rake
hash -r


Sample Rails App Running in JRuby

Then create your test rails app in JRuby. I used that idea of a book store application:


rails bookstore
cd bookstore


Go ahead and do a smoke test by booking up the server.

jruby script/server


Should see a default rails page at

• http://localhost:3000

ActiveRecord JDBC Setup

Kill WEBrick and install the ActiveRecord JDBC gem:


gem install ActiveRecord-JDBC
Installing ri documentation for ActiveRecord-JDBC-0.3.1...
Installing RDoc documentation for ActiveRecord-JDBC-0.3.1...
Successfully installed ActiveRecord-JDBC-0.3.1


Modify the config/database.yml:


development:
adapter: jdbc
driver: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost/bookstore_development
username: root
password:


Modify config/environment.rb to add jdbc as an adapter type. The code goes just above Rails::Initializer.run

Get the MYSQL JDBC driver at:

• http://www.mysql.com/products/connector/j/

I grabbed the file mysql-connector-java-5.0.6-bin.jar and added it to my $JRUBY_HOME/lib. You can also add it to your $CLASSPATH instead.

Start your MySQL server if it isn't running. I just do this from the MySQL Preferences pane.

Time to setup the databases:


mysql -u root
create database bookstore_development;
create database bookstore_test;
exit


Go back to the rails app and create a model for Books.


jruby script/generate model Book


Create a simplistic migration script in the file db/migrate/001_create_books.rb:

Run the migration:


rake db:migrate


Then create the scaffolding for Book:


jruby script/generate scaffold Book


Startup the server:


jruby script/server


Go to the URL and see the scaffolding using JDBC:

• http://localhost/books/

Running the Tests

You should be able to run the rake command and run all the tests now. Instead you get an error about like this:


rake aborted!
Task not supported by 'jdbc'


Turns out this is due to some hard coded values in the rails rake tasks. It has an easy fix by way of Ola Bini:


cd $JRUBY_HOME/lib/ruby/gems/1.8/gems/ActiveRecord-JDBC-0.3.1/lib
svn checkout svn://rubyforge.org/var/svn/jruby-extras/trunk/activerecord-jdbc/lib/tasks


This pulls down a file jdbc_databases.rake that I could only find in the subversion repository for now. Copy that file to the bookstore lib/tasks directory:


cp tasks/jdbc_databases.rake ~/jruby_stuff/bookstore/lib/tasks
cd ~/jruby_stuff/bookstore


Time to run all the default tests with rake:


rake


All the tests pass!

Create the WAR

Kill WEBrick again and install the rails-integration plugin to deploy setup rake tasks to create wars:


jruby script/plugin install svn://rubyforge.org/var/svn/jruby-extras/trunk/rails-integration/plugins/goldspike


It appears the war created uses the production settings so you'll need to create the production database:


mysql -u root
create database bookstore_production;
exit


Then fix the config/database.yml to include jdbc adapters for test and production:


test:
adapter: jdbc
driver: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost/bookstore_test
username: root
password:


production:
adapter: jdbc
driver: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost/bookstore_production
username: root
password:


Go ahead and run the migration for production as well:


rake db:migrate RAILS_ENV=production


Then you run:


rake war:standalone:create

Assembling web application
Adding Java library commons-pool-1.3
Adding Java library activation-1.1
Adding Java library jruby-complete-0.9.9
Adding Java library bcprov-jdk14-124
Adding Java library rails-integration-1.1.1
Adding web application
Adding Ruby gem rails version 1.2.3
Adding Ruby gem rake version 0.7.3
Adding Ruby gem activesupport version 1.4.2
Adding Ruby gem activerecord version 1.15.3
Adding Ruby gem actionpack version 1.13.3
Adding Ruby gem actionmailer version 1.3.3
Adding Ruby gem actionwebservice version 1.2.3
Adding Ruby gem ActiveRecord-JDBC version 0.3.1
Creating web archive


This may take a few minutes the first time, but it appears to be much faster in subsequent builds.

Deploy to Tomcat

At this point you just need to drop the mysql JDBC driver in TOMCAT's lib directory at:


$TOMCAT_HOME/common/lib/mysql-connector-java-5.0.6-bin.jar


Copy the bookstore.war file to


cp bookstore.war $TOMCAT_HOME/webapps/


Then startup Tomcat:


$TOMCAT_HOME/bin/startup.sh


Goto the app at:

• http://localhost:8080/bookstore/books/

Now do your happy dance! Or maybe just take a break and grab a soda.

Sources

I got this recipe for deployment together from several sources:

• The general recipe was cobbled together from Buggy Velarde.
• Ola Bini for the getting started tutorials with JRuby.
• Nick Sieger for his post on ActiveRecord JDBC.
• And the Rails Integration article on the JRuby wiki.

Things To Come

• Deploy a big rails app.
• Deploy to a commercial container like Websphere Appliation Server.

Ed Gibbs @ May 25, 2007