How can you use IIS as a reverse proxy for Apache or Nginx?

1 Why use IIS as a reverse proxy?

IIS is a popular web server and application platform for Windows servers. It has many features and modules that can enhance your web applications, such as URL rewriting, caching, compression, authentication, authorization, logging, and more. By using IIS as a reverse proxy, you can leverage these features for your Apache or Nginx web server, without having to modify your existing configuration or code. For example, you can use IIS to rewrite URLs, cache static content, compress responses, or enforce SSL for your Apache or Nginx web server.

2 How to install and configure IIS as a reverse proxy?

To use IIS as a reverse proxy for Apache or Nginx, you need to install and configure two modules: URL Rewrite and Application Request Routing. URL Rewrite is a module that allows you to create rules to manipulate incoming and outgoing URLs, such as rewriting, redirecting, or appending query strings. Application Request Routing is a module that enables you to route requests to different servers based on various criteria, such as load balancing, health checking, or affinity. You can install these modules from the Microsoft Web Platform Installer or the IIS Manager.

To configure IIS as a reverse proxy, you need to create a server farm that contains your Apache or Nginx web server as a member. A server farm is a group of servers that can handle requests from IIS. You can create a server farm from the IIS Manager, by clicking on Server Farms and then Create Server Farm. You need to specify the name of the server farm, the address and port of your Apache or Nginx web server, and the load balancing algorithm. You can also enable health tests and affinity settings for your server farm.

After creating the server farm, you need to create a URL rewrite rule that matches the incoming requests and routes them to the server farm. You can create a URL rewrite rule from the IIS Manager, by clicking on the site or application where you want to apply the rule, and then clicking on URL Rewrite. You need to specify the name of the rule, the pattern to match the requests, and the action to route them to the server farm. You can also modify the conditions, server variables, and headers of the rule.

3 How to test and troubleshoot IIS as a reverse proxy?

Testing if your IIS reverse proxy is working can be done with a browser or a tool like curl, which sends requests to your IIS site or application and checks if they are forwarded to your Apache or Nginx web server. Additionally, the IIS Manager or the Failed Request Tracing feature can monitor and trace the requests and responses between IIS and your Apache or Nginx web server. To enable Failed Request Tracing, select the site or application from the IIS Manager, click on Failed Request Tracing Rules and specify the conditions and events to trace, as well as the directory to store the trace files. If you encounter any issues with your IIS reverse proxy, such as errors, timeouts, or unexpected results, it is recommended to check the logs of your IIS and your Apache or Nginx web server for errors or warnings. Additionally, check the configuration of your IIS modules, server farm, and URL rewrite rule for accuracy. Furthermore, ensure that network connectivity and firewall settings between your IIS and your Apache or Nginx web server are not blocking or interfering with the requests or responses. Lastly, assess the performance and resource usage of your IIS and your Apache or Nginx web server to make sure they are not overloaded or exhausted.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?