Domain Ownership error. No CNAME records were found. Please add a CNAME record pointing to myapp.azurewebsites.net

The problem is due to a conflict between CloudFlare's CNAME flattening and Azure's CNAME verification. The CNAME flattening essentially returns A records, which speeds up DNS resolution and is a good idea in general. However, Azure's CNAME verification only verifies CNAME records.

The best workaround I've found is to:

  1. Disable CloudFlare's HTTP proxying (click the orange cloud on that CNAME record so that it turns grey); this also disables CNAME flattening for that record.
  2. Check your host on dig until you see the CNAME records show up.
  3. Verify your CNAME host on the Azure portal.
  4. Re-enable CloudFlare's HTTP proxying (click the grey cloud on that CNAME record so it turns orange).

This allows you to verify on Azure and still take advantage of CloudFlare's CDN.