I am setting up a SaaS application written in PHP. Now every user gets a subdomain.appname.com where subdomain is user's choice. So there can be subdomain1.appname.com, subdomain2.appname.com and so on.
I have setup the CNAME entry too as a user's domain so that subdomain1.customerdomain.com points to subdomain1.appname.com and when I try subdomain1.customerdomain.com it perfectly loads the subdomain1.appname.com with subdomain1.customerdomain.com in the address bar.
As soon as I hit any link in the app, the domain in the address bar changes to subdomain1.appname.com which is obvious because there is no htaccess rule yet. And that's where I need help..I suck at htaccess, so what should be the htaccess file like to handle domain masking and keeping user's domain in the address bar all the time.