This article - https://msdn.microsoft.com/en-gb/library/hh534477.aspx#sec7 explains the below approach on how to let customers add custom domains and map to your application.
As an alternative you could allow each tenant to create its own DNS entry that maps a domain or subdomain owned by the tenant to one of your application’s DNS names. For example, Adatum could create the following DNS entry in its DNS configuration:
surveys.adatum.com CNAME adatum.tailspinsurveys.com
Or Adatum could create the following entry:
surveys.adatum.com CNAME www.tailspinsurveys.net
In either case you could use the custom domain name in your ASP.NET routing by using the technique suggested in option 3 above, or use the Request.Url class in your code to identify the domain.
I can achieve this so far with subdomains but when I create the CNAME below to my application I end up with a 404 (Web App not found). I don't want to have to add a custom domain inside azure for each customer. I'd like to automate the process for my SaaS site. Thanks
