A Solution for Getting Proper Certs

You will need certbot installed on a machine.

As of June 2022, it is again possible to simply install it on a Debian machine.

• sudo apt install certbot

Caveats & other Notes

The following certbot command lines are "manual" runs. Working on how best to make dns challenges work in "automatic"...

Both of these techniques require that machines have SSH enabled for root...

Every command above is run as root. (could also be run using sudo)

One possible (sort of...) answer would be to just install certbot under Proxmox since it defaults to having SSH enabled for root anyhow. This might be quite suitable for the Second Method.

Obtaining Certs using DNS instead of http

Each machine you're obtaining a cert for will trigger a message like the following from certbot:

dns-01 challenge for server0.tinkernet.ca

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Please deploy a DNS TXT record under the name
_acme-challenge.server0.tinkernet.ca with the following value:

UaealZG5388lSqUWztK_5HnE_ew_GXsMqxyuRfumriY

Before continuing, verify the record is deployed.
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Press Enter to Continue

You will need to log into your public facing DNS server & create the required TXT record, then WAIT FOR IT TO PROPEGATE before hitting Enter.

Once the certs are obtained, you'll be moving them to their final homes. Note that, in the following 2 examples, the destinations are all /etc/letsencrypt/live/. This will actually be a rare case. More likely, they will need to be in a different location & be renamed. (All depends on the OS & package you're getting them for...)

First Method: Working from the machine with certbot installed on it

• certbot -d server0.tinkernet.ca,server1.tinkernet.ca,server2.tinkernet.ca,server3.tinkernet.ca --manual --preferred-challenges dns certonly
• scp -R /etc/letsencrypt/live/server0.tinkernet.ca/ server0:/etc/letsencrypt/live/
• scp -R /etc/letsencrypt/live/server1.tinkernet.ca/ server1:/etc/letsencrypt/live/
• scp -R /etc/letsencrypt/live/server2.tinkernet.ca/ server2:/etc/letsencrypt/live/
• scp -R /etc/letsencrypt/live/server3.tinkernet.ca/ server3:/etc/letsencrypt/live/

Second Method: Working from the machine being certified

• ssh root@certifier certbot -d server0.tinkernet.ca --manual --preferred-challenges dns certonly
• scp -R root@certifier:/etc/letsencrypt/live/server0.tinkernet.ca/ /etc/letsencrypt/live/