Azure Websites Canonical HostName Rule - Loop Redirect

Question

I have 2 custom domains set up on Azure Websites: mydomain.lt and www.mydomain.lt

DNS registrar's settings:

Subdomain and redirect:

awverif -> CNAME: awverify.mydomain.azurewebsites.net
www -> CNAME: mydomain.azurewebsites.net

Other redirects: IP: 137.x.x.x (IP address provided by Azure) and MX: 79.x.x.x

I can reach my website via mydomain.lt and www.mydomain.lt

What I am trying to do now is to set my Canonical URL in a way, that users coming from www.mydomain.lt would be automatically redirected to mydomain.lt and all relative URL paths returned in a lower case.

I added settings bellow to system.WebServer on Web.config:

<rewrite>
  <rules>

    <!-- SEO | Section 1 | Whitelist -->
    <rule name="Whitelist - Resources" stopProcessing="true">
      <match url="^(?:css/|scripts/|bundles/|images/|install/|config/|umbraco/|umbraco_client/|base/|webresource\.axd|scriptresource\.axd|__browserLink|[^/]*/arterySignalR/.*)" />
      <conditions logicalGrouping="MatchAll" trackAllCaptures="false" />
      <action type="None" />
    </rule>

    <!-- SEO | Section 2 | Rewrites (chaining) -->
    <rule name="SEO - Lower case" stopProcessing="false">
      <match url="(.*)" ignoreCase="false" />
      <conditions logicalGrouping="MatchAll" trackAllCaptures="false">
        <add input="{HTTP_METHOD}" pattern="GET" />
        <add input="{R:1}" pattern="[A-Z]" ignoreCase="false" />
      </conditions>
      <action type="Rewrite" url="_{ToLower:{R:1}}" />
    </rule>

    <!-- SEO | Section 3 | Redirecting -->
    <rule name="SEO - HTTP canonical redirect" stopProcessing="true">
      <match url="^(_*)(.*)" />
      <conditions logicalGrouping="MatchAll" trackAllCaptures="true">
        <add input="{HTTP_HOST}" pattern="^www\.(.*)" />
        <add input="{HTTP_METHOD}" pattern="GET" />
        <add input="{SERVER_PORT}" pattern="80" />
      </conditions>
      <action type="Redirect" url="http://{C:1}/{R:2}" />
    </rule>
    <rule name="SEO - Non-canonical redirect" stopProcessing="true">
      <match url="^(_+)(.*)" />
      <conditions logicalGrouping="MatchAll" trackAllCaptures="false">
        <add input="{HTTP_METHOD}" pattern="GET" />
      </conditions>
      <action type="Redirect" url="{R:2}" />
    </rule>
  </rules>
</rewrite>

The resulting behaviour is a redirect loop. Any ideas how to fix this problem?

Answer 1

It seems the problem is with Azure Websites. The link below gives a workaround how to fix the problem temporarily.

http://social.msdn.microsoft.com/Forums/wpapps/en-US/ee3a5f97-8a58-4b42-a2d9-a73cd5d12c01/issues-with-redirect-rules-used-in-url-rewrite-feature?forum=windowsazurewebsitespreview

I've rewritten my rules and everything works just fine:

<rewrite>
  <rules>
    <rule name="Whitelist - Resources" stopProcessing="true">
      <match url="^(?:css/|scripts/|bundles/|content/|images/|install/|config/|umbraco/|umbraco_client/|base/|webresource\.axd|scriptresource\.axd|__browserLink|[^/]*/arterySignalR/.*)" />
      <conditions logicalGrouping="MatchAll" trackAllCaptures="false" />
      <action type="None" />
    </rule>
    <rule name="Convert to lower case" stopProcessing="true">
      <match url=".*[A-Z].*" ignoreCase="false" />
      <action type="Redirect" url="{ToLower:{R:0}}" redirectType="Permanent" />
    </rule>
    <rule name="Canonical Host Name" patternSyntax="Wildcard" stopProcessing="true">
      <match url="*" />
      <conditions logicalGrouping="MatchAll">
        <add input="{REMOTE_PORT}" pattern="*" />
        <add input="{HTTP_HOST}" pattern="mydomain.lt" negate="true" />
      </conditions>
      <action type="Redirect" url="http://mydomain.lt/{R:1}" redirectType="Permanent" />
    </rule>
  </rules>
</rewrite>

Answer 2

Start by simplifying your rewrite rules to narrow down the problem:

• Instead of using rewrite for www, just update the CNAME for www.domain.com to point to domain.com
• remove section 3 till you get section 2 working
• then try updating section 2 to:

<!-- SEO | Section 2 | Rewrites (chaining) -->
<rule name="SEO - Lower case" stopProcessing="false">
  <match url="(.*)" ignoreCase="false" />
  <conditions logicalGrouping="MatchAll" trackAllCaptures="false">
    <add input="{HTTP_METHOD}" pattern="GET" />
    <add input="{R:1}" pattern="[A-Z]" ignoreCase="false" />
  </conditions>
  <action type="Redirect" url="{ToLower:{R:1}}" RedirectType="Permanent"/>
</rule>