Domain does not resolve for non-www URL in a Heroku-Cloudflare Configuration

[JF0001]

I have an app deployed on Heroku and using Cloudflare as my DNS Server. I have generated an SSL Certificate on Cloudflare and successfully uploaded it on Heroku. I have obtained my DNS Target from Heroku and created the following two CNAMEs on Cloudflare:

CNAME mydomain.com "Proper DNS Target from Heroku" Proxied
CNAME www "Proper DNS Target from Heroku" Proxied

I have also created the following rule on Cloudflare:

https://mydomain.com/*
Forward URL to https://www.mydomain.com/$1

The URL https://www.mydomain.com resolves properly. However, it doesn’t when I do not use the “www” (i.e. https://mydomain.com ).

I have tried numerous different configurations suggested online, but none worked.

Any idea?

[KianNH]

Without seeing your DNS setup or the website domain, it’s hard to be able to suggest anything other than recommending to go over one of the guides (i.e https://support.cloudflare.com/hc/en-us/articles/205893698-Configure-Cloudflare-and-Heroku-over-HTTPS) & make sure you’ve followed every step.

You should have two different CNAME targets from Heroku which need to be added to the right record in Cloudflare’s DNS.

[JF0001]

Thank you @KianNH Yes, I have carefully followed that guide and did obtain 2 different CNAME Targets from Heroku and used the proper ones for each corresponding CNAMEs on Cloudflare, but nothing seems to work (proof that I haven’t mixed them is that the URL using the www works). I will look at it again. Thanks again.

[KianNH]

I vaguely recall someone else having the same kind of issues in the past (setting up @ and www for a Heroku site) but I can’t really remember what their solution ended up being.

When you say that the root domain doesn’t work, what exactly does ‘not working’ entail?

Can you visit the site but get a Heroku ‘not found’ or are you getting a Cloudflare error page?

[JF0001]

I am getting “This site can’t be reached”. If I use try curl -I mydomain.com, I get “Could not resolve host”. Thus, the problem seems to be on the Cloudflare side.

[KianNH]

Just to sanity check, try these two commands:

dig mydomain.com
dig mydomain.com.mydomain.com

I don’t actually know how it’s possible (since entering mydomain.com instead of @ will treat it as if you meant @ in the UI) but I’ve seen it before.

[JF0001]

Yes, this was the problem!!! Although I wasn’t seeing a duplicate domain name in the CNAME Field, it has answered on both dig commands. After editing the CNAME using only “@”, the non-www url started resolving. I must have initially entered the domain name when creating the CNAME. I thank you very, very much! Have a Great day.

[KianNH]

I’ve never actually been able to recreate it myself - no matter how I do it, new record or changing an existing one, entering mydomain.com as the record name is put on mydomain.com rather than mydomain.com.mydomain.com like in your case.

[andreasmarvell]

Kian which software u use to coomunicate dig command