Is it possible to integrate assets with Clouflare CDN service ? In docs only Amazon, Google and Rackspace are referred.
Cloudflare's CDN isn't a true CDN like Amazon, Rackspace, or Google.
With Cloudflare you host your assets on the server and Cloudflare then automatically keeps a cached copy of that.
In other words, you don't upload to CloudFlare, CloudFlare downloads from you.
So on Craft, simply use the "Local folder" source type.