How to map an Azure App Service Web App virtual directory to Azure Storage Container

OK, so I tricked you…you can’t do what is said in the title, well I better not say you can’t because someone could possibly come up with a a way, but what I should say is that if you try to create a virtual directory in the portal as shown in Figure 1, that points to an Azure Storage Container, you will get the following error:

Failed to update web app settings for map-vd-storage: {"Code":"BadRequest","Message":"The provided directory https://****** is not located within site\\.","Target":null,"Details":[{"Message":"The provided directory https://******* is not located within site\\."},{"Code":"BadRequest"},{"ErrorEntity":{"ExtendedCode":"04034","MessageTemplate":"The provided directory {0} is not located within {1}.","Parameters":["https://*******","site\\"],"Code":"BadRequest","Message":"The provided directory https://******* is not located within site\\."}}],"Innererror":null}


Figure 1, how to codeless point an Azure Web App to an Azure Storage Container

Instead of trying to do that, you might consider using a URL Rewrite rule as shown here.

        <rule name="Redirect to storage">
          <match url="^images/.*"/>
          <action type="Redirect" url="https://***{R:0}" redirectType="Permanent" />

The URL Rewrite rule is looking for any request that contains ^images/.* in it.  What does the ^ (caret) mean in the URL Rewrite rule?  It means “look at the beginning of the line” when using the caret ( ^ ) the expression needs to be found anywhere in the URL and the .* (dot star) matches zero or more of any character.  If a match is made, then the request is redirected to my Azure Storage container, for example a request made to:

http://? would match the rule and the request would be redirected to https://?

The following HTML code, hosted on an Azure App Service Web App would be redirected to the Azure Storage Container:

    <title>How to redirect a request to an Azure Web App to an Azure Blob Storage Container</title>
    <img src="https://******" />

This approach does result in a 301, see Figure 2, I did not try to find any way around that, share if you know.  Otherwise, HTH!


Figure 2, how to redirect requests to an Azure Web App to Azure Storage

Comments (0)

Skip to main content