./certbot-auto --server https://acme-v02.api.letsencrypt.org/directory -d "*.xxx.com" --manual --preferred-challenges dns-01 certonly
http://www.infoq.com/cn/news/2018/03/lets-encrypt-wildcard-https
./certbot-auto --server https://acme-v02.api.letsencrypt.org/directory -d "*.xxx.com" --manual --preferred-challenges dns-01 certonly
http://www.infoq.com/cn/news/2018/03/lets-encrypt-wildcard-https