一、apache2安裝：
sudo apt-get install apache2

二、啟動錯誤：
 * Starting web server apache2                                                                                                                                                             (98)Address already in use: AH00072: make_sock: could not bind to address [::]:80
(98)Address already in use: AH00072: make_sock: could not bind to address 0.0.0.0:80
no listening sockets available, shutting down
AH00015: Unable to open logs
Action 'start' failed.
The Apache error log may have more information.
 * 
 * The apache2 instance did not start within 20 seconds. Please read the log files to discover problems

 我的Ubuntu是：80埠被ngnix佔用
 vim /etc/apache2/ports.conf  修改監聽埠
 Listen 1234
 
 三、
 AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.0.1. Set the 'ServerName' directive globally to suppress this message

 vim /etc/apache2/apache2.conf 增加一行
ServerName localhost:2022