执行以下命令即可，以后apt upgrade更新软件，nginx也会自己更新。
sudo sh -c "echo 'deb http://nginx.org/packages/debian/ `lsb_release -cs` nginx' >> /etc/apt/sources.list"
sudo sh -c "echo 'deb-src http://nginx.org/packages/debian/ `lsb_release -cs` nginx' >> /etc/apt/sources.list"
curl http://nginx.org/keys/nginx_signing.key | apt-key add -
sudo apt update
sudo apt install nginx
