最近用部署应用服务，很麻烦的一点就是在docker里修改配置文件。没有vi工具也没有其它编辑器，只能是在外面修改完再导进来，麻烦。
下面给出不用退出docker容器也能修改源（此处用阿里源），步骤如下：
1. 进入docker 容器
命令： docker exec -it containerID(自己的容器ID) /bin/bash
2. 在docker容器内执行如下命令
echo "">/etc/apt/sources.list \
&& echo "deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse">>/etc/apt/sources.list \
&& echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse">>/etc/apt/sources.list \
&& echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse">>/etc/apt/sources.list \
&& echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse">>/etc/apt/sources.list \
&& echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse">>/etc/apt/sources.list \
&& echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse">>/etc/apt/sources.list \
&& echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse">>/etc/apt/sources.list \
&& echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse">>/etc/apt/sources.list \
&& echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse">>/etc/apt/sources.list \
&& echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse">>/etc/apt/sources.list \
&& apt-get clean && apt-get update \
3. 验证安装ping , telnet , vi等工具
命令：
apt-get install iputils-ping (ping 命令)
apt-get install telnet
apt-get install vim
