一、通過系統更換源
第一步：備份原來的源文件
cd /etc/apt/
然后會顯示下面的源文件sources.list
輸入命令
sudo cp sources.list sources.list.bak
就是將sources.list備份到sources.list.bak
第二步：替換源
阿里雲源的文件
deb http://mirrors.aliyun.com/ubuntu/ xenial main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse
##測試版源
deb http://mirrors.aliyun.com/ubuntu/ xenial-proposed main restricted universe multiverse
# 源碼
deb-src http://mirrors.aliyun.com/ubuntu/ xenial main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse
##測試版源
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-proposed main restricted universe multiverse
# Canonical 合作伙伴和附加
deb http://archive.canonical.com/ubuntu/ xenial partner
deb http://extras.ubuntu.com/ubuntu/ xenial main
替換並保存
sudo gedit sources.list打開文件，替換成阿里雲文件即可
第三步：更新源和軟件
sudo apt-get update 更新源
sudo apt-get upgrade 更新軟件
二、通過dockerfile更換ubuntu鏡像中的源為阿里源
在dockerfile中增加如下步驟：
RUN sed -i s/archive.ubuntu.com/mirrors.aliyun.com/g /etc/apt/sources.list \
&& sed -i s/security.ubuntu.com/mirrors.aliyun.com/g /etc/apt/sources.list \
&& apt-get update && apt-get upgrade