Docker下安装vim 报错 E: Unable to locate package vim

1. Docker下安装vim报错如下：

root@1760b5b54639:/etc/mysql# apt-get install -y vim
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package vim

2. 执行apt-get update

 很慢。。。。

3. 修改镜像  清华源

 mv /etc/apt/sources.list /etc/apt/sources.list.bak

echo  "deb http://mirrors.tuna.tsinghua.edu.cn/debian/ buster main contrib non-free" >/etc/apt/sources.list
echo  "deb http://mirrors.tuna.tsinghua.edu.cn/debian/ buster-updates main contrib non-free" >>/etc/apt/sources.list
echo  "deb http://mirrors.tuna.tsinghua.edu.cn/debian/ buster-backports main contrib non-free" >>/etc/apt/sources.list
echo  "deb http://mirrors.tuna.tsinghua.edu.cn/debian-security buster/updates main contrib non-free" >>/etc/apt/sources.list

4. 再次执行apt-get update

root@8d19061fa5fa:/# apt-get update
Get:1 http://mirrors.tuna.tsinghua.edu.cn/debian buster InRelease [122 kB]
Get:2 http://repo.mysql.com/apt/debian buster InRelease [21.5 kB]               
Get:3 http://mirrors.tuna.tsinghua.edu.cn/debian buster-updates InRelease [51.9 kB]
Get:4 http://mirrors.tuna.tsinghua.edu.cn/debian buster-backports InRelease [46.7 kB]
Get:5 http://mirrors.tuna.tsinghua.edu.cn/debian-security buster/updates InRelease [65.4 kB]
Get:6 http://mirrors.tuna.tsinghua.edu.cn/debian buster/contrib amd64 Packages [50.1 kB]
Get:7 http://mirrors.tuna.tsinghua.edu.cn/debian buster/main amd64 Packages [7907 kB]
Get:8 http://repo.mysql.com/apt/debian buster/mysql-5.7 amd64 Packages [5686 B]
Get:9 http://mirrors.tuna.tsinghua.edu.cn/debian buster/non-free amd64 Packages [87.7 kB]
Get:10 http://mirrors.tuna.tsinghua.edu.cn/debian buster-updates/main amd64 Packages [15.2 kB]
Get:11 http://mirrors.tuna.tsinghua.edu.cn/debian buster-backports/main amd64 Packages [488 kB]
Get:12 http://mirrors.tuna.tsinghua.edu.cn/debian buster-backports/non-free amd64 Packages [34.1 kB]
Get:13 http://mirrors.tuna.tsinghua.edu.cn/debian buster-backports/contrib amd64 Packages [9084 B]
Get:14 http://mirrors.tuna.tsinghua.edu.cn/debian-security buster/updates/non-free amd64 Packages [556 B]
Get:15 http://mirrors.tuna.tsinghua.edu.cn/debian-security buster/updates/main amd64 Packages [305 kB]
Fetched 9204 kB in 3s (2867 kB/s)                          
Reading package lists... Done

　

5. 安装 apt-get install -y vim