Why would you want to do this?
After years of having my users connect natively to JBoss application servers in production I have had a few little issues that nagged at me. One of the biggest is that there is not a way to show a custom error page to my users when the JBoss server is down. Second is that I try and limit as much as I can specific configuration details that go into the server configuration so that upgrading between minor releases does not require a lot of configuration editing. Setting up SSL certificates and modifying the default server ports qualifies as hacking up the standard configuration in my book so that is something I would like to limit/avoid.
What we are ultimately trying to do is have an Apache web server handle all the communication between the user and our system. This communication will be secured via SSL. The apache server however has no real content so it will "proxy" the requests to our JBoss application server. The application server will be as simple as possible and will not run SSL.
Our project is named foo
We are going to configure the JBoss server with a virtual host so it can support more than one app if needed.
We want to serve our own error page if the JBoss server cannot process our request due to being down.
This little example is going to be using Ubuntu 12.04.1 LTS and JBoss AS 7.1.3.Final but should be compatible with similar setups.
Let’s do it.
I’m going to assume you have a bare bones Apache 2+ server and JBoss AS7 server setup. If you don’t then search around for some guides. This blog is interested in how to pair them, not the basic setup of each. You should also have a working application and some basic knowledge of how to deploy on AS7. This isn’t meant to be a soup to nuts guide for building and deploying your application.
First create a new directory for our non-proxy (error pages) content /var/www/foo.outjected.com
Go ahead and create a simple error page at /var/www/foo.outjected.com/errors/503.html. This is the page that will be served if the app server is down.
Run the following commands to enable the needed modules in apache
Next go into /etc/apache2/sites-available and create a new file foo.outjected.com+. For this example I’m using a single server so the server I’m proxying to is localhost Your config may/will/should vary.
<VirtualHost *:80> ServerName foo.outjected.com Redirect / https://foo.outjected.com </VirtualHost> <VirtualHost *:443> SSLEngine on SSLCertificateFile /etc/apache2/ssl/foo.outjected.com.pem ServerName foo.outjected.com ProxyRequests Off ProxyPreserveHost On ProxyPassReverseCookiePath / / ProxyPass /errors/ ! ProxyPass / ajp://localhost:8009/ ProxyPassReverse / ajp://localhost:8009/ ErrorDocument 503 /errors/503.html DocumentRoot /var/www/foo.outjected.com ErrorLog /var/log/apache2/foo.outjected.com_errors.log </VirtualHost>
Now enable the site.
If you restart apache you should now see your 503 page as our JBoss server isn’t setup yet.
Setting up the JBoss Server
My JBoss AS7 install is at /usr/local/jboss so adjust your paths as necessary.
Edit /usr/local/jboss/standalone/configuration/standalone.xml and make these two modifications under the web subsystem
# Add the ajp connector # Add a virtual-server entry for foo.outjected.com
Should look something like this.
<subsystem xmlns="urn:jboss:domain:web:1.2" default-virtual-server="default-host" native="false"> <connector name="http" protocol="HTTP/1.1" scheme="http" socket-binding="http"/> <connector name="ajp" protocol="AJP/1.3" scheme="http" socket-binding="ajp" enabled="true"/> <virtual-server name="default-host" enable-welcome-root="true"> <alias name="localhost"/> <alias name="example.com"/> </virtual-server> <virtual-server name="foo" enable-welcome-root="false" default-web-module="foo"> <alias name="foo.example.com"/> </virtual-server> </subsystem>
Your EAR/WAR is going to need a jboss-web.xml (foo.war/WEB-INF/jboss-web.xml) which will define the virtual host and set the context root
<?xml version="1.0"?> <!DOCTYPE jboss-web PUBLIC "-//JBoss//DTD Web Application 5.0//EN" "http://www.jboss.org/j2ee/dtd/jboss-web_5_0.dtd"> <jboss-web> <context-root>/</context-root> <virtual-host>foo</virtual-host> </jboss-web>
Start up your JBoss server as normal and enjoy your new proxied setup.