之前写过一个在Asp.Net Core里调用System.Drawing.Common绘图的DEMO，部署到Docker里运行，需要更新Asp.Net Core镜像的操作系统。

https://www.cnblogs.com/sunnytrudeau/p/9384620.html

当时用的阿里云的源

RUN echo "deb http://mirrors.aliyun.com/debian wheezy main contrib non-free \
deb-src http://mirrors.aliyun.com/debian wheezy main contrib non-free \
deb http://mirrors.aliyun.com/debian wheezy-updates main contrib non-free \
deb-src http://mirrors.aliyun.com/debian wheezy-updates main contrib non-free \
deb http://mirrors.aliyun.com/debian-security wheezy/updates main contrib non-free \
deb-src http://mirrors.aliyun.com/debian-security wheezy/updates main contrib non-free" > /etc/apt/sources.list

最近再次跑这个Demo，居然不好使了，更新系统无效了，创建容器失败：

Step 4/11 : RUN apt-get update

 ---> Running in 69abe26c3b35

Ign:1 http://mirrors.aliyun.com/debian wheezy InRelease

Ign:2 http://mirrors.aliyun.com/debian wheezy Release

Ign:3 http://mirrors.aliyun.com/debian wheezy/deb all Packages

……

Ign:14 http://mirrors.aliyun.com/debian wheezy/http://mirrors.aliyun.com/debian amd64 Packages

Reading package lists...

W: The repository 'http://mirrors.aliyun.com/debian wheezy Release' does not have a Release file.

E: Failed to fetch http://mirrors.aliyun.com/debian/dists/wheezy/non-free/binary-amd64/Packages  404  Not Found [IP: 124.203.224.198 80]

E: Some index files failed to download. They have been ignored, or old ones used instead.

ERROR: Service 'myweb' failed to build: The command '/bin/sh -c apt-get update' returned a non-zero code: 100

百度学习了一下，才知道Asp.Net Core的Docker镜像是基于debian这个Linux发行版构建的，以前用的版本是wheezy，现在用的新版本是stretch

版本号以及代号     发布日期

7 wheezy            2013年5月4日

8 Jessie             2015年4月26日

9 stretch            2017年06月17日

所以，更新操作系统的源相应的更换一下就可以了。

RUN echo "deb http://mirrors.aliyun.com/debian stretch main contrib non-free \
deb-src http://mirrors.aliyun.com/debian stretch main contrib non-free \
deb http://mirrors.aliyun.com/debian stretch-updates main contrib non-free \
deb-src http://mirrors.aliyun.com/debian stretch-updates main contrib non-free \
deb http://mirrors.aliyun.com/debian-security stretch/updates main contrib non-free \
deb-src http://mirrors.aliyun.com/debian-security stretch/updates main contrib non-free \
deb http://mirrors.aliyun.com/debian/ stretch-backports main non-free contrib \
deb-src http://mirrors.aliyun.com/debian/ stretch-backports main non-free contrib" > /etc/apt/sources.list

可以进入运行中的Asp.Net Core容器查看操作系统版本

[root@localhost ~]# docker exec -it fd70cac69589 /bin/bash

root@fd70cac69589:/app# cat /etc/issue

Debian GNU/Linux 9 \n \l