I was privileged to recieve one of the early Let's Encrypt beta certificates for https://hoverbear.org. I had an easy and fun time setting it up this evening on my Funtoo Container and wanted to quickly jot down how to!

Get 'er Done

I first needed some prerequisites (I already had nginx installed):

sudo emerge -vqa augeas python-augeas dialog

Then, following the instructions provided:

git clone https://github.com/letsencrypt/letsencrypt
cd letsencrypt
./letsencrypt-auto --agree-dev-preview --server \
  https://acme-v01.api.letsencrypt.org/directory auth

From here you'll be brought to something that looks like a make menuconfig when building your own kernel... But a lot easier. From here you have two options, "Manual" and "Standalone".

Manual asks you for your domain then tasks you with the job of hosting a file under something like $YOUR_DOMAIN/.well_known/acme-challenge/$KEY.

Standalone will make an effort to automatically verify your domain for you by hosting it's own web server. (You'll need to stop your existing nginx server if you have one.)

Gotchas

Let's Encrypt only issues certificates that are good for 90 days, so you need to regularly renew! There is a MWoS'2015 Project to make this renewal automated.