How do I allow multiple NAMES.domain.com for my web app?

Question

Hi all;

I have a Blazor app running on Azure App Server. You presently get to it using ohana.tradewindsstudios.us which works great.

I want to allow MyName.tradewindsstudios.us, YourName.tradewindsstudios.us, AnyName.tradewindsstudios.us, etc. to go to the website (basically anything except tradewindsstudios.us and www.tradewindsstudios.us.

1. I am following the instructions here and App Server | Custom Domain | Validate is not finding the TXT asuid. Any idea why it might not?
2. How do I have Azure generate a cert for the *.tradewindsstudios.us domains? I have the Azure self generated cert for ohana.tradewindsstudios.us.

Also, and maybe this works. I don't know because of the blockers above. But do I need to do anything so that someone coming to the site using MyName.tradewindsstudios.us continues to have that as the root of their url as they move through the website. I do not want it reverting to ohana.tradewindsstudios.us.

And in Blazor, how do I get what they are using? NavigationManager?

thanks - dave

ps - For those curious, my app manages volunteer events for political campaigns. I want to give them the ability to show upcoming events that are for just their campaign.

Answer 1

Wildcard certificate requests

If you want to use the free certificates generated by Azure, then you have to add individual custom domains one by one and allow Azure to request/generate one certificate for each of them.

However, if you want a wildcard certificate (*.tradewindsstudios.us), then you have to use a certificate authority of your own and purchase a wildcard certificate from them. This is documented very well by Microsoft in this article, and a dedicated article for GoDaddy (but you are not limited to this CA)

The free certificate comes with the following limitations:

• Doesn't support wildcard certificates.

Wildcard custom domains validation

If you just want to add wildcard custom domains to your App Service (or other Azure services like Contain Apps), simply try to add *.tradewindsstudios.us like any other custom domain (like test.tradewindsstudios.us) by choosing "Add certificate later".

The CNAME check is not strict, so you can add it anytime you like before deploying the web app. (So, even if this check shows a warning, you can move on).

The TXT check tip seems to be inconsistent right now from different Azure products, and some might not show a correct tip. My testing shows that as long as you configured asuid and asuid.www properly, it will pass, so you don't need to configure asuid.*.

Note that since inconsistency can be observed right now, this answer might be just valid right now and might be invalidated by future changes in Azure.