Route requests from a plug-in to a proxy server

We can set up a web server plug-in to route requests to a proxy server.

An administrator might choose to set up a web server, such as IBM HTTP Server, with the web server plug-in as a front-end to the proxy server. The plug-in configuration file for such a topology cannot use the traditional plug-in configuration generation mechanism if the requests are routed through the proxy server.

To generate the plugin-cfg.xml file to use with the web server plug-in to route through the proxy server...

1. From the console, click Servers > Server Types > WebSphere proxy servers > proxy_server_name > HTTP proxy server settings > Proxy settings.

2. In the Generate plug-in configuration drop-down menu, select the appropriate scope.

3. Optional: If we have a script that manually copies the plugin-cfg.xml file from the node to the plug-in installation location, enter the path to the script in the Plugin config change script field.

4. In the Trusted Security Proxy field, add the hostname or IP address of the node for the plug-in that serves as the trusted intermediary for the proxy server.

5. Click OK.

6. Disable the automatic propagation of the plug-in if you are using IBM HTTP Server with remote administration. From the console, click Servers > Server Types > Web Servers > web_server_name > Plug-in properties. Deselect Automatically propagate plugin configuration file. This will prevent WebSphere Application Server from copying the traditional plugin-cfg.xml file over the proxy server plugin-cfg.xml file.

7. Save the changes.

8. Stop and restart the proxy server. The plugin-cfg.xml file will be in the {WAS_ROOT}/profiles/profilename/etc directory unless the plug-in was generated for the server scope. If we generated the plug-in for the server scope, the plugin-cfg.xml file will be in the {WAS_ROOT}/profiles/profilename/etc/server_name directory. If we do not have a script in thePlugin config change script field, manually copy the plugin-cfg.xml file to the plug-in.

   Avoid trouble: During the plugin-cfg.xml generation process temporary plugin-cfg-xxxx.xml files are created. If we notice any of these temporary files in the same directory as the plugin-cfg.xml file, we can either ignore them, or manually delete them.gotcha

Results

After a plugin-cfg.xml file is initially generated, it is automatically regenerated whenever the On Demand Configuration (ODC) changes, For example, the plugin-cfg.xml file is regenerated whenever an application is installed or uninstalled, or the weights assigned to one or more proxy server cluster members changes.

What to do next

To verify that the proxy server trusts the web server, add the host name or address of the web server to the Trusted security proxies section on the Proxy Settings page in the console. To reach this page, click Servers > Server Types > WebSphere proxy servers > proxy_server_name > HTTP proxy server settings > Proxy settings This enables the proxy server to honor the private headers that are set by the fronting intermediary server.