In Openshift you need to point (as it's recommended on Openshift) your domain to their CNAME records, like that:
mysite.com => cname: app-mynick.rhcloud.com
But according to DNS rules (as my domain registrator says) CNAME pointing applicable only for subdomains like this:
subdomain.mysite.com
So, how should I behave in this situation with my top level domain?
The problem is Openshift gives my app dynamic IP, so, somewhen it may be changed and my website wouldn't be accessible...