I know that I am a little late to the party, but since I had a valid SSL certificate at the time I did not pay any attention to this great new service called Let's Encrypt.
Recently I started working on a new and exciting project that required an SSL certificate. I remembered hearing about something that offered free SSL certificates and decided to give it a chance. The installation and configuration went smoothly without a problem and everything worked.
I am writing this tutorial to show you how to obtain and install a free SSL certificate from Let's Encrypt on Nginx web server running on Ubuntu 14.04. You can view the gist for this tutorial here.