AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 172.18.0.2. Set the 'ServerName' directive globally to suppress this message

1.这个异常是在apache2重启时出现的

2.解决方式

vim /etc/apache2/apache2.conf
#在文件最后添加一行
ServerName localhost:80
#然后保存并重启Apache2
service apache2 restart