1. 首选要创建一个Dockerfile文件，内容如下：

FROM alpine:latest

MAINTAINER  lobin <lobin.hotmail.com>

RUN apk add --no-cache --update-cache bash

CMD ["/bin/bash"]

2. 生成镜像,取名apline-bash

[root@VM_0_13_centos demo]# docker build -t apline-bash .

Sending build context to Docker daemon 2.048 kB

Step 1/4 : FROM alpine:latest

---> 3fd9065eaf02

Step 2/4 : MAINTAINER lobin <lobin.hotmail.com>

---> [Warning] IPv4 forwarding is disabled. Networking will not work.

---> Running in a73f8500b494

---> 398e9ed5537e

Removing intermediate container a73f8500b494

Step 3/4 : RUN apk add --no-cache --update-cache bash

---> [Warning] IPv4 forwarding is disabled. Networking will not work.

---> Running in dd629be23601

fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/main/x86_64/APKINDEX.tar.gz

fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/main/x86_64/APKINDEX.tar.gz

ERROR: http://dl-cdn.alpinelinux.org/alpine/v3.7/main: temporary error (try again later)

WARNING: Ignoring http://dl-cdn.alpinelinux.org/alpine/v3.7/main/x86_64/APKINDEX.tar.gz: temporary error (try again later)

fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/community/x86_64/APKINDEX.tar.gz

ERROR: http://dl-cdn.alpinelinux.org/alpine/v3.7/community: temporary error (try again later)

fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/community/x86_64/APKINDEX.tar.gz

bash (missing):

required by: world[bash]

WARNING: Ignoring http://dl-cdn.alpinelinux.org/alpine/v3.7/community/x86_64/APKINDEX.tar.gz: temporary error (try again later)

ERROR: unsatisfiable constraints:

The command '/bin/sh -c apk add --no-cache --update-cache bash' returned a non-zero code: 1

3. 出现以上错误，没辙，重启docker能解决，但问题不知道

[root@VM_0_13_centos demo]# systemctl restart docker

4. 重新构建镜像

[root@VM_0_13_centos demo]# docker build -t apline-bash .

Sending build context to Docker daemon 2.048 kB

Step 1/4 : FROM alpine:latest

---> 3fd9065eaf02

Step 2/4 : MAINTAINER lobin <lobin.hotmail.com>

---> Using cache

---> 398e9ed5537e

Step 3/4 : RUN apk add --no-cache --update-cache bash

---> Running in 4ce990201bfd

fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/main/x86_64/APKINDEX.tar.gz

fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/main/x86_64/APKINDEX.tar.gz

fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/community/x86_64/APKINDEX.tar.gz

fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/community/x86_64/APKINDEX.tar.gz

(1/6) Installing pkgconf (1.3.10-r0)

(2/6) Installing ncurses-terminfo-base (6.0_p20171125-r0)

(3/6) Installing ncurses-terminfo (6.0_p20171125-r0)

(4/6) Installing ncurses-libs (6.0_p20171125-r0)

(5/6) Installing readline (7.0.003-r0)

(6/6) Installing bash (4.4.19-r1)

Executing bash-4.4.19-r1.post-install

Executing busybox-1.27.2-r7.trigger

OK: 13 MiB in 17 packages

---> b6ed2497fc7e

Removing intermediate container 4ce990201bfd

Step 4/4 : CMD /bin/bash

---> Running in 61323661705d

---> a7414979d240

Removing intermediate container 61323661705d

Successfully built a7414979d240

[root@VM_0_13_centos demo]#

Message from syslogd@localhost at Jul  4 23:49:17 ...

kernel:unregister_netdevice: waiting for lo to become free. Usage count = 1

Message from syslogd@localhost at Jul  4 23:49:27 ...

kernel:unregister_netdevice: waiting for lo to become free. Usage count = 1

5. 查看镜像，好小呀

[root@VM_0_13_centos demo]# docker images

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE

apline-bash         latest              a7414979d240        8 minutes ago       9.5 MB

docker.io/redis     latest              71a81cb279e3        7 days ago          83.4 MB

docker.io/mysql     latest              8d99edb9fd40        7 days ago          445 MB

docker.io/alpine    latest              3fd9065eaf02        5 months ago        4.15 MB