From: Charles Oliver Nutter <charles.nutter@...>
Date: 2009-04-26T00:12:48+09:00
Subject: Re: Running JRuby behind an Apache server

Robert Klemme wrote:
> No no, I meant, using Tomcat, Jetty or the like with JRuby.  Sorry, the 
> question was definitively not precise enough.

Well, they both work great as far as I know. In Tomcat's case, you would 
use Warbler to package up your app as a .war file and then deploy that. 
I believe Jetty can work the same way, though there's also a jetty_rails 
gem that's similar to the glassfish gem.

> Erm, what do you mean by that?  With a proper configuration and JRuby's 
> libraries deployed starting Tomcat should be enough.  What am I missing?

Well, managing a Tomcat instance isn't as simple as just running one 
command. With JRuby you have exactly *one* process for your whole app, 
and if you can run Rails with config.threadsafe! enabled, you have 
exactly *one* JRuby instance within that process. Just about as easy as 
it gets.

Maybe it's worth showing the steps to run JRuby behind Apache here:

Prerequisites:

1. Apache with mod_proxy_http enabled (sudo a2enmod proxy_http on 
Ubuntu). Every default apache I know ships with mod_proxy_http.
2. Java (on Debian/Ubuntu)sudo apt-get install sun-java6-jdk or the 
openjdk flavors if you like)
3. JRuby (download, unpack, put bin/ in PATH)
4. gems appropriate to run your app with JRuby (e.g. rails, 
activerecord-jdbcsqlite3-adapter, etc)
5. production DB all set to go

Once you have that, the remaining set up is trivial:

1. Install the glassfish gem (or you can use Mongrel too...see my post):

   gem install glassfish

2. From your application directory, run glassfish with these options:

   glassfish -p <port> -e production -c <context> -d

3. Add ProxyPass and ProxyPassReverse lines to Apache (whereever is 
appropriate on your system) for the GlassFish server instance. For 
example, if <port> is 9000 and <context> is foo:

   ProxyPass /foo http://localhost:9000/foo
   ProxyPassReverse /foo http://localhost:9000/foo

4. Reload Apache config, however is appropriate for your system

That's it!

- Charlie