link apache web server on port 80 and tomcat webapp on port 8080

Question

On port 80 I have normal apache web server.

On port 8080 I have tomcat with client and server side stuff.

My goal is:

www.mydomain.com renders a static and SEO friendly index.html while javascript stuff is loading.

In the header of this index.html I load www.mydomain.com:8080/myapp/stuff.js

stuff.js is compiled with gwt and calls a RootLayoutPanel.get().add(nice_panel) which will remove static content and show dynamic widgets. It also calls servlets (server side code).

Problem: for security reasons, browsers wont let me load www.mydomain.com:8080/myapp/stuff.js because it is on a different port.

Wrong attempt: I tried to create a symlink from "normal" apache web server directory to the tomcat webapp containing stuff.js. I am now able to load stuff.js because its url is: www.mydomain.com/mysymlink_to_tomcat/stuff.js. But stuff.js is not able anymore to call servlets on server side again because of browsers security rules ("XMLHttpRequest cannot load ... origin ...is not allowed by Access-Control-Allow-Origin").

I would like to avoid the "crazy" solution of redirect from index.html to tomcat with header('location: http://mydomain.com:8080/another_index_on_tomcat.html'). This solution works but it has many drawbacks (SEO...)

What would be the best approach ?

Thanks.

Serve evertyhing with Tomcat on move it to port 80? – madth3 Oct 22 '12 at 23:18 — madth3, Oct 22 '12 at 23:18

score 3 · Accepted Answer · answered Oct 22 '12 at 23:40

You have basically two solutions:

make it work with the 2 origins: use the xsiframe linker in GWT to allow the page on :80 to load the script from :8080 (for readers: it's not about loading, it's about what the script does). Add the following to your `gwt.xml:
```
<add-linker name='xsiframe' />
```
That unfortunately won't solve your issue with GWT-RPC (o whatever you use to talk to the server). For that, there's CORS.
use a single origin: use Apache's mod_proxy (or mod_jk) to proxy your Tomcat through your Apache. Nobody will ever use :8080, everything will go through :80. See Using Tomcat with Apache HTTPD and a proxy at https://developers.google.com/web-toolkit/doc/latest/DevGuideServerCommunication#DevGuideRPCDeployment

And of course there's also the solution of ditching the HTTPD and serving everything with Tomcat (recent Java and Tomcat versions have fixed their slowness issues).

Thank you Thomas. I like the "use a single origin" approach. I am now trying to do it and let you know as soon as possible. Unfortunately I am having a "500 Internal Server Error" and I do no know how to get rid of it. — Gauthier, Oct 23 '12 at 06:45
Done it ! The "single origin" finally works fine. I had to take into account: http://stackoverflow.com/questions/1517290/problem-with-gwt-behind-a-reverse-proxy-either-nginx-or-apache to make everything going well. Thank you so much. — Gauthier, Oct 23 '12 at 15:26

score 1 · Answer 2 · answered Oct 22 '12 at 23:08

1

I'm not sure if this would avoid the security error, but you could try an iframe. On apache, you have the index and an iframe to the tomcat, where the JS loads inside the iframe. Dunno if that will help with the SEO problem.

answered Oct 22 '12 at 23:08

bobbybee

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Athanasios Kataras · Answer 3 · 2012-10-23T07:04:08.253

The best solution would be to redirect the port 80 calls to 8080 on apache when the client call is asking for a tomcat application.

Install mod_jk on apache and configure it to mount a context on the path you want example: (edit /mods_enabled/jk.conf)

# Configure access to jk-status and jk-manager
# If you want to make this available in a virtual host,
# either move this block into the virtual host
# or copy it logically there by including "JkMountCopy On"
# in the virtual host.
# Add an appropriate authentication method here!
<Location /jk-status>
    # Inside Location we can omit the URL in JkMount
    JkMount jk-status
    Order deny,allow
    Deny from all
    Allow from 127.0.0.1
</Location>
<Location /jk-manager>
    # Inside Location we can omit the URL in JkMount
    JkMount jk-manager
    Order deny,allow
    Deny from all
    Allow from 127.0.0.1
</Location>

JkMount /*/myAppDir/* ajp13

Then add a virtual host in your site settings (edit /apache2/sites-enabled/)

    <VirtualHost *:80>
    . Here is the rest of the
    . of the config of
    . the host
    # Tomcat jk connector settings
    JkMount /*.jsp ajp13_worker
    JkMount /myAppDir/* ajp13_worker
    JkMount /myAppDir* ajp13_worker
    JKMount /manager* ajp13_worker
    JkMount /manager/* ajp13_worker
    </VirtualHost>

And you should also edit the server.xml file and inside the tag write and comment the previous Host name="localhost"

<!-- Define an AJP 1.3 Connector on port 8009 -->

<Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />

<Host name="localhost" appBase="webapps" unpackWARs="true"
   autoDeploy="true" >

          <Context path="/" docBase="/var/lib/tomcat7/webapps/myAppDir/"
                       debug="0" reloadable="true" />
          <!-- please notes on logs down below -->
     <Valve className="org.apache.catalina.valves.AccessLogValve"
             directory="/var/lib/tomcat7/logs" prefix="tomcat_access_" 
            suffix=".log" pattern="common" resolveHosts="false" />
  </Host>

The only thing left to do is edit the workers.properties file and add

worker.myapp2.port=8009
worker.myapp2.host=localhost
worker.myapp2.type=ajp13
worker.loadbalancer.type=lb
worker.loadbalancer.balance_workers=ajp13_worker

Then you should be set to work, and when a url containing the myAppDir appears, the apache server will redirect the calls to tomcat the answer will come back from apache.

Thank you for your detailed answer. As far as I know, I prefer to use mod_proxy like Tomas Brower suggest, so I do not have to create any connector which is not an easy matter for unexpert people. — Gauthier, Oct 23 '12 at 15:29

link apache web server on port 80 and tomcat webapp on port 8080

3 Answers3