acme.sh - Obtain Let's Encrypt certificate for Nginx vhost
My test platform: Debian 9.9
Requirements: user with root privileges or non-root user with sudo privileges.
acme.sh installation
$ sudo su - root
git clone https://github.com/Neilpang/acme.sh.git
cd acme.sh
./acme.sh --install --accountemail your_email@yourdomain.com
source ~/.bashrc
cd ~
acme.sh --version