Heroku custom url works as redirect instead of alias

Question

I added domains to my heroku project:

 $ heroku domains
=== diveintoworld Heroku Domain
diveintoworld.herokuapp.com
=== diveintoworld Custom Domains
Domain Name            DNS Target
─────────────────────  ───────────────────────────
diveintoworld.com      diveintoworld.herokuapp.com
www.diveintoworld.com  diveintoworld.herokuapp.com

$ host www.diveintoworld.com
www.diveintoworld.com is an alias for diveintoworld.herokuapp.com.

Created CNAME record in my domain settings:

www.diveintoworld.com. CNAME diveintoworld.herokuapp.com.

And set up web redirect from diveintoworld.com to www.diveintoworld.com.

Seems like nothing was missed but all these things work like redirect.
www.diveintoworld.com->diveintoworld.herokuapp.com

But I need to make my site available under www.diveintoworld.com. (When user see my site he should see this url rather than heroku url in his address line.)

Answer 1

When I run

curl -s -I www.diveintoworld.com

It returns a 301. Which means that your app might be doing the unexpected redirect.

HTTP/1.1 301 Moved Permanently
Server: Cowboy
Connection: keep-alive
X-Powered-By: Express
Location: https://diveintoworld.herokuapp.com/
Vary: Accept, Accept-Encoding
Content-Type: text/plain; charset=utf-8
Content-Length: 70
Date: Thu, 21 Apr 2016 05:34:24 GMT
Via: 1.1 vegur

X-Powered-By: Express is from the express.js framework which I'm assuming is the one you used to develop your website. Do you have somewhere in your app code a redirect to the heroku url? Perhaps an environment specific config that sets the app host?

UPDATE - SOLVED

The problem was a misconfiguration of the HEROKU_URL in the configuration of the app. In this case the Ghost platform was used and the config documentation for the url is available here.

Setting HEROKU_URL with http://www.diveintoworld.com, clearing cache or trying in private tab did the trick.