How can I redirect a port number on Linux?

Question

I have a Tomcat application running on my Linux machine on port 8080 (www.myapplication.com:8080/myapps).

I want to redirect the Tomcat port :8080 to the default HTTP port of :80 so that the application can be accesed without a port number (www.myapplication.com/myapps).

How can I do that on Linux?

Answer 1

You should never face the Tomcat or any other Java application server to the external world. The best practice is to install Apache HTTPD and use it a reverse proxy to wrap Tomcat or JBoss.

I recommend to do the following.

1. Install httpd:

   yum install httpd

2. Create file

   /etc/httpd/conf.d/myredirect.conf

   with the following content:

   ProxyPass   http://127.0.0.1:8080/myapps/
   ProxyPassReverse       http://127.0.0.1:8080/myapps/
   

3. If the application resides in the root than the configuration will be the following:

   ProxyPass   http://127.0.0.1:8080/
   ProxyPassReverse       http://127.0.0.1:8080/
   

4. Restart httpd:

   service httpd restart

The instructions above are provided for RedHat-family linux. They may differ for other ones.

Answer 2

There so many ways to achieve this, but first which comes to my mind is to use nginx: http://serverfault.com/questions/180800/how-to-permanently-redirect-port-8080-url-to-port-80-using-nginx

Another one is to use iptables: http://www.cyberciti.biz/faq/linux-port-redirection-with-iptables/

Answer 3

first you should change server.xml file, change "Connector port="8080" " to "80". the file may be at /etc/tomcat6, or you could use "locate server.xml" to find it.

second you should change the default tomcat6 configure file, in my system (debian squeeze) is /etc/default/tomcat6, add the line: AUTHBIND=yes.

restart your tomcat.

then you can use www.myapplication.com/myapps to access your app.

Answer 4

You could use iptables to redirect port 80 to 8080.

This is useful if your application is started by an unprivileged user instead of root.

iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 8080

HTH, PEra