How to request Let’s Encrypt wildcard certificate?

Background

I am tired getting the certificate error every time I access my servers at home. Those servers have no access to the public network. I need to create the certificate manually.

Certbot

Certbot is a free, open source software tool for automatically using Let’s Encrypt certificates on manually-administrated websites to enable HTTPS. This will be used to create the TLS certificates which then will be installed on the internal servers.

Configuration

Let’s install Certbot using Brew

brew install certbot

I don’t have any servers with port 80 open but I have access to my DNS. So I use DNS installation method in which you need to add a TXT record.

sudo certbot certonly --manual --preferred-challenges dns

Follow the setup process. When it prompts on which domain would need the TLS certs to be requested, please use asterisk (*) in front of the chosen domain name.

*.ardho.nl

Continue the process of adding the txt records in the DNS and eventually the keys will then be created and can be installed on all the servers.