= Warbler

Warbler is a gem to make a Java jar or war file out of any Ruby,
Rails, Merb, or Rack application. Warbler provides a minimal,
flexible, Ruby-like way to bundle up all of your application files for
deployment to a Java environment.

Warbler provides a sane set of out-of-the box defaults that should allow most
Ruby applications to assemble and Just Work.

== Getting Started

1. Install the gem: <tt>gem install warbler</tt>.
2. Run warbler in the top directory of your application: <tt>warble</tt>.
3a. For a web project, deploy your myapp.war file to your favorite Java
application server.
3b. For a standalone applications, just run it: <tt>java -jar myapp.jar</tt>.

== Usage

Warbler's +warble+ command is just a small wrapper around Rake with internally
defined tasks.

$ warble -T
warble compiled # Feature: precompile all Ruby files
warble config # Generate a configuration file to customize your archive
warble executable # Feature: make an executable archive
warble gemjar # Feature: package gem repository inside a war
warble pluginize # Install Warbler tasks in your Rails application
warble version # Display version of Warbler
warble war # Create the project war file
warble war:clean # Remove the project war file
warble war:debug # Dump diagnostic information

Type <tt>warble</tt> to create the jar or war file.

== Features

Warbler "features" are small Rake tasks that run before the creation
of the war file and make manipulations to the archive structure. For
instance, the +executable+ feature makes your war file capable of
running on its own, without a servlet container:

warble executable war

You can either add features to the warbler command line:

warble FEATURE war

or configure them in config/warble.rb to always be used.

config.features = %w(FEATURE)

Currently, three features are available.

* +gemjar+: This bundles all gems into a single gem file to reduce the
number of files in the .war. This is mostly useful for Google
AppEngine where the number of files per application has a limit.
(Note: not applicable for jar-based applications.)
* +executable+: This bundles an embedded web server into the .war so
that it can either be deployed into a traditional java web server or
run as a standalone application using <tt>java -jar myapp.war</tt>.
(Note: jar-based applications are executable by default.)
* +compiled+: This uses +jrubyc+ to precompile all .rb files in your
application to .class files and includes those in the .war instead
of the Ruby sources.

Features may form the basis for a third-party plugin system in the
future if there is demand.

== War or Jar?

War-based projects are for Rails, Merb, or Rack-based web
applications. They usually contain a <tt>config/environment.rb</tt>
file, a <tt>config/init.rb</tt> file, or a <tt>config.ru</tt> file.
The presence of these files are used to determine if the project
is a web application, and thus a Java EE compatible war file is built
for the project.

Jar-based projects are for standalone Ruby applications. Usually a
Ruby application has a launcher script in the <tt>bin</tt> directory
and Ruby code in the <tt>lib</tt> directory. Warbler packages the
application so that <tt>java -jar myapp.jar</tt> runs the launcher

== Jar Files

=== Gem Specification (gemspec) Files

If your project has a <tt>.gemspec</tt> file in the top directory, it
will be used to configure the project's dependencies, launcher script,
require paths, and the files to be included in the archive. For best
results make sure your gemspec specifies all of the following

* +executables+
* +require_paths+
* runtime dependencies added with +add_dependency+

If your project do not have a <tt>.gemspec</tt>, Warbler will attempt
to guess the launcher from the contents of the <tt>bin</tt> directory
and use the <tt>lib</tt> directory as the lone require path. All files
in the project will be included in the archive.

=== Bundler

Applications that use Bundler[http://gembundler.com/], detected via
presence of a +Gemfile+, will have the gems packaged up into the
archive along with the Gemfile. The Bundler groups named
+:development+ and +:test+ will be excluded by default, unless you
specify with +config.bundle_without+ in +config/warble.rb+.

Warbler supports Bundler for gems and git repositories, but not for
plain path components. Warbler will warn when a +:path+ component is
found in the +Gemfile+ and will refuse to include it in the archive.

== War Files

=== Rails applications

Rails applications are detected automatically and configured appropriately.
The following items are set up for you:

* Your application runs in the +production+ environment by default.
Change it in <tt>config/warble.rb</tt> (see below).
* The Rails gem is packaged if you haven't vendored Rails (Rails <= 2.x).
* Other gems configured in Rails.configuration.gems are packaged
(Rails 2.1 - 2.3)
* Multi-thread-safe execution (as introduced in Rails 2.2) is detected
and runtime pooling is disabled.

=== Merb applications

Merb applications are detected automatically, and the merb-core gem and its
dependencies are packaged.

=== Other Rack-based applications

If you have a +config.ru+ file in the top directory or one of the
immediate subdirectories of your application, it will be included and
used as the rackup script for your Rack-based application. You will
probably need to specify framework and application gems in
config/warble.rb unless you're using Bundler to manage your gems.
<tt>ENV['RACK_ENV']</tt> will be set to +production+.

See examples in the jruby-rack project[http://github.com/nicksieger/jruby-rack/tree/master/examples/]
of how to configure Warbler to package Camping and Sinatra apps.

=== Configuration auto-detect notes

* Warbler will load the +environment+ Rake task in a Rails application
to try to detect some configuration. If you don't have database
access in the environment where you package your application, you
may wish to set +Warbler.framework_detection+ to false at the top of
config.rb. In this case you may need to specify additional details
such as booter, gems and other settings that would normally be
gleaned from the application configuration.
* A more accurate way of detecting a Merb application's gems is
needed. Until then, you will have to specify them in
+config/warble.rb+. See below.
* Is it possible to more generally detect what gems an application
uses? Gem.loaded_specs is available, but the application needs to be
loaded first before its contents are reliable.

== Custom configuration

If the default settings are not appropriate for your application, you can
customize Warbler's behavior. To customize files, libraries, and gems included
in the .war file, you'll need a config/warble.rb file. There a two ways of
doing this. With the gem, simply run

warble config

Finally, edit the config/warble.rb to your taste. The generated
config/warble.rb file is fully-documented with the available options
and default values.

=== War layout

The default configuration puts application files (+app+, +config+, +lib+,
+log+, +vendor+, +tmp+) under the .war file's WEB-INF directory, and files in
+public+ in the root of the .war file. Any Java .jar files stored in lib will
automatically be placed in WEB-INF/lib for placement on the web app's

=== Web.xml

Java web applications are configured mainly through this file, and Warbler
creates a suitable default file for you for use. However, if you need to
customize it in any way, you have two options.

1. If you just want a static web.xml file whose contents you manually
control, you may unzip the one generated for you in
<tt>yourapp.war:WEB-INF/web.xml</tt> to <tt>config/web.xml</tt> and
modify as needed. It will be copied into subsequent copies of the
war file for you.
2. If you want to inject some dynamic information into the file, copy
the <tt>WARBLER_HOME/web.xml.erb</tt> to
<tt>config/web.xml.erb</tt>. Its contents will be evaluated for you
and put in the webapp. Note that you can also pass arbitrary
properties to the ERb template by setting
<tt>config.webxml.customkey</tt> values in your
<tt>config/warble.rb</tt> file.

For more information on configuration, see Warbler::Config.

== Rakefile integration

If you'd like to control Warbler from your own project's Rakefile,
simply add the following code somewhere in the Rakefile:

require 'warbler'

If you're using Bundler, you'll want to add Warbler to your Gemfile:

group :development do
gem "warbler"

Now you should be able to invoke "rake war" to create your war file.

== Troubleshooting

If Warbler isn't packaging the files you were expecting, use the
+war:debug+ task to give you more insight into what's going on.

If you think you found a bug, please file one at

== Source

You can get the Warbler source using Git, in any of the following ways:

git clone git://git.caldersphere.net/warbler.git
git clone git://github.com/nicksieger/warbler.git
git clone git://kenai.com/warbler~main

You can also download a tarball of Warbler source at

== Development

You can develop Warbler with any implementation of Ruby. To write
Warbler code and run specs, you need to have Bundler installed
and run "bundle install" once.

After that, simply run "rake".

== License

Warbler is provided under the terms of the MIT license.

Warbler (c) 2010-2011 Engine Yard, Inc.
Warbler (c) 2007-2009 Sun Microsystems, Inc.