https://www.cnblogs.com/alexlv/p/11956255.html
https://www.cnblogs.com/heqiuyong/p/10460150.html
sudo systemctl status firewalld
sudo systemctl stop firewalld
sudo systemctl start firewalld
firewall-cmd --zone=public --add-port=80/tcp --permanent
firewall-cmd --reload
firewall-cmd --list-ports