Assign domain to a subdomain in a Heroku application

Question

I am not sure if the following scenario can be done on Heroku:

• I have an application that runs on Heroku (myapp.herokuapp.com) in which each user can get a subdomain like foo.example.com. From what I read, this can be done by wildcarding the subdomain. Adding *.example.com to the Heroku domains and then set the DNS provider to point to the Heroku application (myapp.herokuapp.com)
• Then, they should be able to link bar.com to foo.example.com. But, how can this be achieved?

Any help is appreciated. Thanks!

Answer 1

The Heroku Dev Center has an article that is kept up to date and answers all of this:

• Heroku Dev Center: Custom Domains

You CNAME *.example.com to your Heroku app, and you add *.example.com to your Heroku domains. It's up to your application code to make sense of it all after that.

Answer 2

I to get it working like this:

Add the following CNAMES

• *.example.com -> myapp.herokuapp.com
• bar.com -> foo.example.com (look for host instead of subdomain inside application and load the needed data based on that)

Add the domaines on Heroku

• *.example.com
• bar.com