make-a-war-file.markdown

Here are the basic steps to create a war file from a Rails application. This is what Warbler does.

1. Make a staging directory to create the structure, and make a WEB-INF directory in side of that.

2. Copy your application code into the WEB-INF directory.

   %w(app config lib vendor).each {|d| cp_r d, web_inf_dir }

3. Copy your public assets into the root of the staging directory.

   FileList["public/**/*"].each {|f| cp f, File.join(staging_dir, f.sub(%r{public/}, '')) }

4. Create a WEB-INF/web.xml file. Example contents follows.

5. Copy the jruby-core and jruby-stdlib jars from the jruby-jars gem into WEB-INF/lib.

6. Copy the jruby-rack jar into WEB-INF/lib.

7. Jar the whole thing up.

   jar cf myapp.war -C staging_dir .

There are details around configuring gems, customizing web.xml, and specifying additional libraries in the war file, and Warbler's configuration helps with that.

web.xml

<!DOCTYPE web-app PUBLIC
  "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
  "http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>

  <context-param>
    <param-name>rails.env</param-name>
    <param-value>production</param-value>
  </context-param>

  <context-param>
    <param-name>public.root</param-name>
    <param-value>/</param-value>
  </context-param>

  <context-param>
    <param-name>jruby.max.runtimes</param-name>
    <param-value>1</param-value>
  </context-param>

  <context-param>
    <param-name>jruby.min.runtimes</param-name>
    <param-value>1</param-value>
  </context-param>


  <filter>
    <filter-name>RackFilter</filter-name>
    <filter-class>org.jruby.rack.RackFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>RackFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

  <listener>
    <listener-class>org.jruby.rack.rails.RailsServletContextListener</listener-class>
  </listener>
</web-app>