Azure CDN Microsoft Standard Rules Engine Rewrite URL for single-page-application

I finally got a working answer from Microsoft Support on this. They said that the Microsoft CDN Rules Engine does not support URL file extension Not Any and instead I should check for the length of the file extension.

• Condition: URL file extension
  • Operator = Not greater than
  • Extension = 0
  • Case Transform = No transform
• Action: URL rewrite
  • Source Pattern = /
  • Destination = /index.html
  • Preserve unmatched path = No

This solution works for me. Make sure to purge your cdn cache before testing.

If none of your page URLs contain a dot, you can set a rule as follows:

• Condition: 'URL file extension' = Not Any (i.e. there is no extension)
• Action: 'URL rewrite',
  • source = /
  • destination = index.html
  • Preserve umatched path = No

This will rewrite any URL without a dot in the trailing section to index.html.