View source for ReverseProxy for IIS 6.0 in CS using ASP.NET

== Problem to solve ==
We want to embed content from a internal webserver e.g. <code><nowiki>http://foo</nowiki></code> to our public webserver
<code><nowiki>http://sar.informatik.hu-berbin.de</nowiki></code>. In particular the frontend request 
<code><nowiki>http://sar.informatik.hu-berbin.de/test/bla.html</nowiki></code> should get the response for <code><nowiki>http://foo/dir/bla.html</nowiki></code>.
Thus the mapping is:
* <code><nowiki>http://sar.informatik.hu-berbin.de/test -> http://foo/dir</nowiki></code>.
From outside this sould be look like a local web directory.

== Used Software ==
[http://www.saltypickle.com/Home/16 IIS Reverse Proxy] in particular [http://www.saltypickle.com/Home/uploads/16/ReverseProxy(v1.5).zip v1.5].
In that release of software redirections of the backend server are not forwarded transparently to the frontend. Therfore we patched the C-Sharpe code to take care of that. We disabled the internal handling of redirections and transpose them instead to the frontend.
<pre><nowiki>38c38
<   	const int MaximumRedirections = 50;
---
> 		const int MaximumRedirections = 0;
357a358,370
> 			switch((int) backEndResponse.StatusCode) {
> 				case 301:
> 				case 302:
> 				case 303:
> 				case 307:
> 					frontEndResponse.StatusCode = (int) backEndResponse.StatusCode;
> 					string newLocation = backEndResponse.Headers["Location"];
> 					newLocation = Regex.Replace(newLocation, backEndSite, 
> 						frontEndRequest.Url.GetLeftPart(UriPartial.Authority) + frontEndRequest.ApplicationPath, 
> 						RegexOptions.IgnoreCase);
> 					frontEndResponse.RedirectLocation = newLocation;
> 					break;
> 			}</nowiki>
</pre>
Then redirections which usally occur if you enter e.g. <code><nowiki>http://foo/dir -> http://foo/dir/</nowiki></code> are forwarded to the browser as <code><nowiki>http://sar.informatik.hu-berbin.de/test -> http://sar.informatik.hu-berbin.de/test/</nowiki></code>

== Installation ==
Based on [http://www.saltypickle.com/Home/20 W2k/XP], [http://www.saltypickle.com/Home/19 Win2003]
=== Walk through ===
# Create Direktory where software lives e.g. <code>C:\Inetpub\test_virtual</code> and extract archive <code>"\\dc\pub\2006\2006 Software\ReverseProxy_15_SAR.zip"</code> to that directory. [[Image:rproxy_1.png]]
# Create in the IIS MMC a virtual directory [[Image:rproxy_2.png]]
# Give the alias name under which the resource should be reachable by the frontend <code>test</code> [[Image:rproxy_3.png]]
# Select the Web Site Conten Directory <code>C:\Inetpub\test_virtual</code> [[Image:rproxy_4.png]]
# OK. [[Image:rproxy_5.png]]
# Check the Properties of the virtual dir. [[Image:rproxy_6.png]]