Renew LetsEncrypt certificates monthly on Ubuntu 14.04

Let's install the command line client somewhere useful and setup some directories

git clone https://github.com/letsencrypt/letsencrypt /opt/letsencrypt
mkdir /etc/letsencrypt/configs
touch /var/log/letsencrypt.log

We'll create some files as needed for each of the groups of domains we wish to renew, at /etc/letsencrypt/configs, and use letsencrypt-example.ini as a template for it. Finally, we should add renew-letsencrypt.sh to our crontab

crontab -e
# @monthly /path/to/renew-letsencrypt.sh 2>&1 >> /var/log/letsencrypt.conf

Nginx

We'll have to configure each non-https server to serve the challenge responses by doing something like this:

server {
  listen 80;
  server_name www.domain.tld domain.tld;

  # Serve the challenge responses
  location /.well-known/acme-challenge {
    root /var/www/letsencrypt;
  }
  
  # Redirect to https otherwise
  location / {
  	return 301 https://domain.tld$request_uri;
  }
}