Get HTTPS with Free SSL/TLS from Let's Encrypt
who doesn't love free stuff? yea, now you can get HTTPS for free with SSL/TLS certificate from Let's Encrypt.
btw, Let's Encrypt client now become certbot .
oh anyway, here's my command line to generate certificate manually (prepare the challenge response first before getting the certificate verification) for multiple sub-domains.
git clone https://github.com/certbot/certbot.git
or if you want to manually finish the challenge
sudo ./letsencrypt-auto -a manual certonly