Maybe this is more of a home lab question, but I'm utterly clueless regarding PKI and HTTPS certs, despite taking more than one class that goes into some detail about how the system works. I've tried finding guides on how to set up your own CA, but my eyes glaze over after the third or fourth certificate you have to generate.
Anyway, I know you need a public DNS record for HTTPS to work, and it struck me recently that I do in fact own a domain name that I currently use as my DNS suffix on my LAN. Is there a way I can get Let's Encrypt to dole out a wildcard certificate I can use on the hosts in my LAN so I don't have to fiddle with every machine that uses every service I'm hosting? If so, is there a guide for the brain dead one could point me to? Maybe doing this will help me grock the whole PKI thing.
UPDATE:
Here's what I ended up doing:
- set up cloudflare as the DNS provider for my domain
- use certbot plus the cloudflare DNS plugin to create a wildcard cert. Because I want to use wildcard certs and because the web servers are on a NATed private LAN, HTTP-01 challenge cannot be used. Wildcard certs use a DNS challenge. From what I understand of the certbot docs, the HTTP challenge makes a certain HTTP resource available on the web server, then requests that resource, presumably via an external client, to verify that you own the domain. the DNS challenge works by temporarily placing a TXT record in your DNS server. This method requires your DNS provider to have an accessible API that allows the modification of resource records.
- Once the cert and key are generated, I place them on the servers I want to to make use of them and set up the web server accordingly.
- Visit the websites and confirm that HTTPS works.
There are some other hiccups that I'm guessing aren't related to HTTPS. Per My earlier question about self hosting, I'm experimenting with NodeBB. I cannot get the two test instances to federate, which I initially assumed was an issue with HTTPS. That's a question best asked elsewhere, though I thought it relevant to note because it was my initial purpose for setting up HTTPS.
I use Caddy for this. I'll leave links to the documentation as well as a few examples.
Here's the documentation for wildcard certs. https://caddyserver.com/docs/automatic-https#wildcard-certificates
Here's how you add DNS providers to Caddy without Docker. https://caddy.community/t/how-to-use-dns-provider-modules-in-caddy-2/8148
Here's how you do it with Docker. https://github.com/docker-library/docs/tree/master/caddy#adding-custom-caddy-modules
Look for the DNS provider in this repository first. https://github.com/caddy-dns
Here's documentation about using environment variables. https://caddyserver.com/docs/caddyfile/concepts#environment-variables
Docker
A few examples of Dockerfiles. These will build Caddy with DNS support.
DuckDNS
Cloudflare
Porkbun
Configure DNS provider
This is what to add the the Caddyfile, I've used these in the examples that follow this section. You can look at the repository for the DNS provider to see how to configure it for example.
DuckDNS
https://github.com/caddy-dns/cloudflare?tab=readme-ov-file#caddyfile-examples
CloudFlare
https://github.com/caddy-dns/cloudflare?tab=readme-ov-file#caddyfile-examples Dual-key
Single-key
PorkBun
https://github.com/caddy-dns/porkbun?tab=readme-ov-file#config-examples Global
or per site
Caddyfile
And finally the Caddyfile examples.
DuckDNS
Here's how you do it with DuckDNS.
Also you can use environment variables like this.
CloudFlare
Porkbun
The advice I needed and have not been able to find. I could kiss you. Or at least give you a fond nod.