查詢redis防火墻的示例：
[root@localhost demo]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
Active: active (running) since 三 2019-03-06 00:56:15 PST; 2min 43s ago
Docs: man:firewalld(1)
Main PID: 630 (firewalld)
CGroup: /system.slice/firewalld.service
└─630 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid
3月 06 00:56:14 localhost.localdomain systemd[1]: Starting firewalld - dynamic fir....
3月 06 00:56:15 localhost.localdomain systemd[1]: Started firewalld - dynamic fire....
Hint: Some lines were ellipsized, use -l to show in full.
