CNAME From Customer Domain

Howdy!

I’m not sure if what I’m looking to do is possible. I have an app with a custom domain, I want to have a domain not pointing to Netlify to have a CNAME that points to my Netlify domain.

You can imagine the scenario like this:

  1. I have a SaaS product
  2. I have subdomains for customers (customer1.warroomops.com)
  3. I want customers to be able to use their own CNAME (status.customer1.com —> customer1.warroomops.com)

Current Netlify app: amazing-bartik-6f9118.netlify.app
Existing Custom Domain: amorrissound.warroomops.com
Failed CNAME Redirect: status.amorrissound.com

You can see that status.amorrissound.com just says “Not Found” but it should point to the custom domain that is working. Here is an output from running host:

❯ host status.amorrissound.com
status.amorrissound.com is an alias for amorrissound.warroomops.com.
amorrissound.warroomops.com has address 104.248.78.24
amorrissound.warroomops.com has address 165.227.0.164

Makes total sense, and fortunately, is possible!

Our system figures out what content to serve based on what site a hostname is configured on. So, you’ll need to:

  1. add the hostname (status.amorrissound.com) to the custom domain settings for a site in our admin UI. You can add a few dozen separate names to any site.
  2. when you do that, we try to fetch an SSL certificate for it (in addition to all the OTHER names on your site).
  3. that requires that DNS is setup to point to us and only us (it is in your example), and that there be no blocking “CAA” DNS record to prevent letsencrypt from issuing an SSL certificate for your domain. (there isn’t one for your example domain).

So - should just work once you tell us what content to serve for that name, which contrary to appearances is not communicated by DNS (think of DNS as being a phone book - you’ve called Netlify’s switchboard, but you need to tell us which site to connect the browser to - which you do by configuring a name in our dashboard on a site :))

PS: If you are reselling Netlify (== hosting web content with us, for your customers, whom you charge for the service) we do hope you’ll invest in at least a Pro account.

Thanks! I didn’t realize that I could add status.amorrissound.com; I thought it had to be a domain attached to my Netlify account.

Just out of curiosity, you mentioned “a few dozen separate names”, do you know the exact number? If there is a cap, is it possible to pay to increase it?

I’m absolutely going to be on a Pro account (and higher as I scale). Love Netlify and want to support the service!

Thanks! I didn’t realize that I could add status.amorrissound.com ; I thought it had to be a domain attached to my Netlify account.

If you could point to what led you to that conclusion - community article, docs, blog post, our app’s UI, etc - we’d love to see if we can improve it to be clearer!

Just out of curiosity, you mentioned “a few dozen separate names”, do you know the exact number? If there is a cap, is it possible to pay to increase it?

limit is 100, as that is the most our SSL provider can handle:

If you have a lot of subdomains, you may want to combine them into a single certificate, up to a limit of 100 Names per Certificate .

That limit is a hard limit.

We suggest no more than 50 names per site, PARTICULARLY if you are having customers configure DNS (e.g. yourproduct.theirdomain.com). You will have to provide a fair amount of tech support to those customers of yours around configuring this DNS appropriately - you’ll need to learn about CAA dns records and how to identify ones that will impact us, for instance - so please be aware that this is a pattern other customers use, but that it does cause their teams some struggles to provide that tech support. We’ll be equally available to help you help them, of course, but it’s not going to be a very fast process with you proxying questions to us and us trying to debug the black box. The main customer I am thinking of who does this is now up to 4 separate but identical sites each with dozens of (different) theirproduct.customerdomain.com names on each site, so it is possible to scale this as far as you want to go - just a bit of a hassle.

A different pattern that some customers use with LESS hassle, is the pattern:

yourcustomername.yourproduct.com

We have a feature that allows us to automatically serve *.yourdomain.com the same site WITHOUT particular configuration in the UI. It has a few limitations that I can talk through if you’re curious, namely in that your pattern has to match the *.somedomain.com rather than varying domains.

If you could point to what led you to that conclusion - community article, docs, blog post, our app’s UI, etc - we’d love to see if we can improve it to be clearer!

Just an assumption on my part! :slight_smile: I thought since the domain might not be under my control, then I shouldn’t add it to Netlify.

We have a feature that allows us to automatically serve *.yourdomain.com the same site WITHOUT particular configuration in the UI. It has a few limitations that I can talk through if you’re curious, namely in that your pattern has to match the *.somedomain.com rather than varying domains.

Yeah this feature is excellent. I wasn’t aware you could take advantage of it without configuration in the UI though.

well - you do have to configure things to start with:

  • put a placeholder domain name on the site, e.g. placeholder.yourdomain.com
  • make sure we have an SSL certificate to cover *.yourdomain.com (we handle this if we host your DNS; you purchase and manage the certificate if not)
  • we have to “flip the switch” to enable the feature after we confirm you’re a Pro+ level customer and all other config is correct.

But thereafter, no ADDITIONAL / per-hostname changes are needed to start using newcustomer1.yourdomain.com or newcustomer2.yourdomain.com or anything else matching the pattern