I have successfully customize domain with
rhc alias add tutorial reboltutorial.net
rhc alias add tutorial www.reboltutorial.net
Problem is I cannot add
CNAME .reboltutorial.net tutorial-rebol.rhcloud.com
to my current DNS records
A reboltutorial.net 198.XXX.YYY.ZZZ NA 3600
CNAME www.reboltutorial.net tutorial-rebol.rhcloud.com
So is it possible to add both domain.com and www.domain.com to Openshift ?
Update : well finally even without adding 2nd Cname reboltutorial.net works though I don't understand how if someone can explain to me :)
No that is not possible. You are trying to point an A record ( reboltutorial.net) to a URL and this is not allowed.
Some DNS providers to what is called naked domain forwarding and so you could then point your A record to a C record or direct to the URL.
More is explained in this blog post
https://www.openshift.com/blogs/custom-url-names-for-your-paas-applications-host-forwarding-and-cnames-the-openshift-way