在虚拟机 Ubuntu 中安装Nginx

原镜像源下载速度较慢，所以先切换到阿里的镜像源

• 进入到镜像源所在文件夹

cd /etc/apt

• 将现有的sources.list文件进行备份

sudo cp sources.list sources.list.bak

• 进入sources.list修改镜像源
  进入sources.list

 sudo nano /etc/apt/sources.list 

打开之后ctrl+k逐行清楚（抱歉，小白不知道这里应该怎么一次清除全部），清除完之后粘贴阿里云的镜像源

deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse

粘贴之后按键 Ctrl+X ，会提示你是否保存，输入Y，下一个提示再敲Enter键即可成功保存并退出

• 更新镜像源

 sudo apt-get update

• 此时我出现了另一个错误，如果没有遇到可以忽略
  执行更新的时候提示错误如下
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 3B4FE6ACC0B21F32
  百度查询说原因是因为更换三方源没有对应的key，需要直接执行如下的命令

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 3B4FE6ACC0B21F32

执行之后再重新更新

sudo apt-get update

• 更新之后直接进行Nginx的安装即可

sudo apt-get install nginx

中途会提示Do you want to continue? [Y/n] 输入Y回车即可
安装完成之后查询Nginx版本

nginx -v

能够查询出Nginx版本则成功，Over!