I have a MySQL database that I would like to remotely access from Windows Azure which does not provide fixed IP addresses at this point. Instead of white-listing a very large IP range to cover the entire Microsoft datacenter, it would be preferable to check for the hostname instead. Indeed, if I was allowing `myuser@'foo.example.com', DNS resolution being made when establishing a new connection to MySQL then varying IP address would not be an issue anymore.
Does anyone is such a scheme is possible with MySQL?
MySQL has supported DNS based authentication for a long time. The problem is that it needs you to set up the reverse as well as the forward lookups.
If you are able to set both the forward and reverse records then it all should be easy.
See the section about How MySQL Uses DNS in the manual for full details.