IIS Reverse Proxy Not Working With Response.Redirect() in ASP.NET

Question

I am trying to set up a reverse proxy, using the tutorials here, here and here.

The site is set up on localhost:8080, with the reverse proxy using localhost:8080/myProxy.

When dealing with standard links, all is fine. I can view the proxy url and see everything as expected. A link from localhost:8080/myProxy/default.aspx goes to localhost:8080/myProxy/about.aspx as expected.

The problem I have is that where .NET Response.Redirect() is used, the url changes to the websites actual location instead of the proxy.

i.e. the link goes from localhost:8080/myproxy/default.aspx -> localhost:8080/about.aspx.

How can i resolve this please?

Here is my config:

<system.webServer>
    <modules runAllManagedModulesForAllRequests="true"/>
    <urlCompression doStaticCompression="false" doDynamicCompression="false" 
                    dynamicCompressionBeforeCache="false" />
    <rewrite>
        <rules>
            <rule name="Reverse Proxy to my site" stopProcessing="true">
                <match url="^myProxy/(.*)" />
                <action type="Rewrite" url="http://localhost:8080/{R:1}" />
            </rule>
        </rules>

        <outboundRules>
            <rule name="ReverseProxyOutboundRule1" preCondition="ResponseIsHtml1">
                <match filterByTags="A, Area, Base, Form, Frame, Head, IFrame, Img, Input, Link, Script"
                       pattern="^http(s)?://localhost:8080/(.*)" />
                <action type="Rewrite" value="/myProxy/{R:2}" />
            </rule>
            <rule name="RewriteRelativePaths" preCondition="ResponseIsHtml1">
                <match filterByTags="A, Area, Base, Form, Frame, Head, IFrame, Img, Input, Link, Script" 
                       pattern="^/(.*)" negate="false" />
                <action type="Rewrite" value="/myProxy/{R:1}" />
            </rule>
            <preConditions>
                <preCondition name="ResponseIsHtml1">
                    <add input="{RESPONSE_CONTENT_TYPE}" pattern="^text/html" />
                </preCondition>
            </preConditions>
        </outboundRules>

    </rewrite>
</system.webServer>

Answer 1

Sorry to answer my own question, but I think this is worth putting out there for others info:

When using Response.Redirect, outbound rules come into play. Viewing the requests with Fiddler helped work out what was going on with the links.

Response.Redirect() was trying to send to /About.aspx (Transport in Response Headers).

This was not being picked up by the regex.

The only outbound rule I needed was setting up Response_location as follows:

<rule name="Response Status Update" preCondition="ResponseStatus" stopProcessing="true">
  <match serverVariable="RESPONSE_Location" pattern="^/(.*)" />
  <action type="Rewrite" value="http://myServer:8080/myProxy/{R:1}" />
</rule>

The inbound rule remained unchanged.