今天启动apache查看状态发现报错，说不能确认服务器完全确认域名，以下是报错内容：
[root@localhost ~]# service httpd status
Redirecting to /bin/systemctl status httpd.service
● httpd.service - The Apache HTTP Server
Loaded: loaded (/usr/lib/systemd/system/httpd.service; disabled; vendor preset: disabled)
Active: active (running) since Thu 2019-09-19 16:13:13 CST; 19min ago
Docs: man:httpd(8)
man:apachectl(8)
Process: 4342 ExecStop=/bin/kill -WINCH ${MAINPID} (code=exited, status=0/SUCCESS)
Main PID: 4459 (httpd)
Status: "Total requests: 0; Current requests/sec: 0; Current traffic: 0 B/sec"
CGroup: /system.slice/httpd.service
├─4459 /usr/sbin/httpd -DFOREGROUND
├─4460 /usr/sbin/httpd -DFOREGROUND
├─4461 /usr/sbin/httpd -DFOREGROUND
├─4462 /usr/sbin/httpd -DFOREGROUND
├─4463 /usr/sbin/httpd -DFOREGROUND
└─4464 /usr/sbin/httpd -DFOREGROUND Sep 19 16:13:13 localhost.localdomain systemd[1]: Starting The Apache HTTP Server...
Sep 19 16:13:13 localhost.localdomain httpd[4459]: AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using localhost.localdo...is message ###就是这一个
Sep 19 16:13:13 localhost.localdomain systemd[1]: Started The Apache HTTP Server.
Hint: Some lines were ellipsized, use -l to show in full.
解决办法：
vi /etc/httpd/conf/httpd.conf 加入一句 ServerName localhost:80
然后重启apache服务
[root@localhost ~]# vi /etc/httpd/conf/httpd.conf
[root@localhost ~]# service httpd restart
Redirecting to /bin/systemctl restart httpd.service
[root@localhost ~]# service httpd status
Redirecting to /bin/systemctl status httpd.service
● httpd.service - The Apache HTTP Server
Loaded: loaded (/usr/lib/systemd/system/httpd.service; disabled; vendor preset: disabled)
Active: active (running) since Thu 2019-09-19 16:38:08 CST; 5s ago
Docs: man:httpd(8)
man:apachectl(8)
Process: 4610 ExecStop=/bin/kill -WINCH ${MAINPID} (code=exited, status=0/SUCCESS)
Main PID: 4615 (httpd)
Status: "Processing requests..."
CGroup: /system.slice/httpd.service
├─4615 /usr/sbin/httpd -DFOREGROUND
├─4616 /usr/sbin/httpd -DFOREGROUND
├─4617 /usr/sbin/httpd -DFOREGROUND
├─4618 /usr/sbin/httpd -DFOREGROUND
├─4619 /usr/sbin/httpd -DFOREGROUND
└─4620 /usr/sbin/httpd -DFOREGROUND Sep 19 16:38:08 localhost.localdomain systemd[1]: Starting The Apache HTTP Server...
Sep 19 16:38:08 localhost.localdomain systemd[1]: Started The Apache HTTP Server.
[root@localhost ~]#