Adding proxy server behind WSO2 ESB

When the message flow needs to be routed through a proxy, you need to add following parameters to transportSender configuration in axis2.xml.

http.proxyHost - proxy server's host name
http.proxyPort - port number of the proxy  server
http.nonProxyHosts - any host that need to by pass above proxy

Else you can set Java networking properties.

-Dhttp.proxyHost=example.org -Dhttp.proxyPort=5678 -Dhttp.nonProxyHosts=localhost|127.0.0.1|foo.com

Sample:
This scenario illustrates how a routing via proxy and nonproxy happens. I have echo service in an AppServer which is fronted by stockquaote.org HTTP proxy. I also have SimpleStockQuoteService in localhost which is set as a nonProxyHost.

I have my transport sender in axis2.xml configured as below:

<transportSender name="http" class="org.apache.synapse.transport.passthru.PassThroughHttpSender">
 <parameter name="non-blocking" locked="false">true</parameter>
 <parameter name="http.proxyHost" locked="false">stockquote.org</parameter>
 <parameter name="http.proxyPort" locked="false">8080</parameter>
 <parameter name="http.nonProxyHosts" locked="false">localhost</parameter>
</transportSender> 

Proxy rout:

<proxy name="Echo_viaProxy" transports="https http" startOnLoad="true" trace="disable">
  <description/>
  <target>   
   <endpoint>       
    <address uri="http://xx.xx.xx.xxx:9765/services/Echo"/>    
   </endpoint>    
  <outSequence>      
   <send/>    
  </outSequence>  
 </target>
</proxy>

When you send a request to above SimpleStckQ_viaProxy, the request will be direct to stockquaote.org which will route to BE (http://localhost:9000/services/SimpleStockQuoteService).

nonProxy:

<proxy name="StockQuote_direct"
       transports="https http"
       startOnLoad="true"
       trace="disable">
   <description/>
   <target>
      <endpoint>
         <address uri="http://localhost:9000/services/SimpleStockQuoteService"/>
      </endpoint>
      <outSequence>
         <send/>
      </outSequence>
   </target>
 </proxy>

When you send a request to above StockQuote_direct, the request will be directly served by SimpleStockService in localhost.


known issue and fix:
https://wso2.org/jira/browse/ESBJAVA-3165 is fixed in 4.9.0 M4.