How to maintain get and post data in virtual host?

Question

I have nodejs, php and apache2 running on ubuntu 14.04.

There are nodejs listening on different ports (eg. 3000, 3001...).

So, I want to setup virtual host, so that when user requests the nodejs service, the user can go "http://nodejs.example.com/api" instead of "http://example.com:3001/api" And at the same time, I want to maintain all post/get data being sent.

following is my virtual host configuration:

#/etc/apache2/sites-available/mySite.conf
<VirtualHost *:80>
   ServerAdmin webmaster@localhost
   ServerName example
   ServerAlias nodejs.example.com

   ProxyRequests Off
   ProxyPreserveHost On
   ProxyVia Full
   <Proxy *>
      Require all granted
   </Proxy>

   <Location />
      ProxyPass http://127.0.0.1:3001/
      ProxyPassReverse http://127.0.0.1:3001/

      RewriteEngine On
      RewriteRule http://nodejs.example.com:3001/$1 [R=301,L] 
   </Location>

   ErrorLog ${APACHE_LOG_DIR}/error.log

   # Possible values include: debug, info, notice, warn, error, crit,
   # alert, emerg.
   LogLevel warn

   CustomLog ${APACHE_LOG_DIR}/access.log combined




</VirtualHost>

Can anyone please help?