https://certbot.eff.org/lets-encrypt/centosrhel7-nginx

// centos 7

yum -y install yum-utils

yum-config-manager --enable rhui-REGION-rhel-server-extras rhui-REGION-rhel-server-optional

yum install certbot python2-certbot-nginx

certbot --nginx

// crontab
echo "0 0,12 * * * root python -c 'import random; import time; time.sleep(random.random() * 3600)' && certbot renew" | sudo tee -a /etc/crontab > /dev/null

几步就完成了, 注意事项是, nginx 配置文件不要写中文(注释也不行), 会有编译问题