Hosting a blog on fly.io using ghost

This site is currently on fly.io using ghost. I've pretty much used a guide from Diep Pham whom seems to be using the same techniques he describes. Why I'm even writing this is that the guide seems slightly outdated, or just missing a point.

That single point being, id doesn't explain setting up the custom domain. And if you do this "naively", through the web-ui as that's first place you end up and why would you read the docs while you can click through the dashboard - anyway. The way you do it you need to issue a certificate. But doing using the default deployment only sets up a private ipv4. So the webui for creating the certs only shows you to create a CNAME and the ipv6 AAAA records. But what you also need to do allocate a public one explicitely. Now the fly.io docs do describe this, but it wasn't exactly a first hit on DDG, so that's why I decided to write this.

So hopefully, some other person finds this blog first - because my SEO is so freaking great - before finding the above blog post, and saves himself some time.