introduce FirewallD

FirewallD is frontend controller for iptables used to implement persistent network traffic rules. It provides command line and graphical interfaces and is available in the repositories of most Linux distributions. Working with FirewallD has two main differences compared to directly controlling iptables:

1. FirewallD uses zones and services instead of chain and rules.
2. It manages rulesets dynamically, allowing updates without breaking existing sessions and connections.

https://www.linode.com/docs/security/firewalls/introduction-to-firewalld-on-centos/
https://blog.csdn.net/xiazichenxi/article/details/80169927