Docker File创建镜像失败--ERROR [3/4] RUN yum -y install vim

问题复现：

使用以下内容的Docker File创建镜像：

FROM centos
MAINTAINER xxxxx<[email protected]>

ENV MYPATH /usr/local
WORKDIR $MYPATH

RUN yum -y install vim
RUN yum -y install net-tools

EXPOSE 80

CMD echo $MYPATH
CMD echo "============"
CMD /bin/bash

错误描述：

=> ERROR [3/4] RUN yum -y install vim

---

[3/4] RUN yum -y install vim:
#0 1.627 CentOSLinux 8 - AppStream 61 B/s | 38 B 00:00
#0 1.664 Error: Failed to download metadata for repo 'appstream': Cannot prepare internal mirrorlist: No URLs in mirrorlist

---

---

5 |     WORKDIR $MYPATH
6 |     
7 | >>> RUN yum -y install vim
8 |     RUN yum -y install net-tools
9 |     

---

ERROR: failed to solve: process "/bin/sh -c yum -y install vim" did not complete successfully: exit code: 1

解决问题方法：

分析问题：

[3/4] RUN yum -y install vim:
#0 1.627 CentOSLinux 8 - AppStream 61 B/s | 38 B 00:00
#0 1.664 Error: Failed to download metadata for repo 'appstream': Cannot prepare internal mirrorlist: No URLs in mirrorlist

由上错误描述可知：问题是由于最新版本CentOSLinux 8中vim软件资源下载失败导致。

解决问题：

添加版本信息并修改为7即可。

FROM centos:7 # 添加版本
MAINTAINER xxxxx<[email protected]>

ENV MYPATH /usr/local
WORKDIR $MYPATH

RUN yum -y install vim
RUN yum -y install net-tools

EXPOSE 80

CMD echo $MYPATH
CMD echo "============"
CMD /bin/bash

完成结果：

[+] Building 34.8s (8/8) FINISHED                                                          
 => [internal] load build definition from mycentos                                    0.0s
 => => transferring dockerfile: 306B                                                  0.0s
 => [internal] load .dockerignore                                                     0.0s
 => => transferring context: 2B                                                       0.0s
 => [internal] load metadata for docker.io/library/centos:7                           0.3s
 => [1/4] FROM docker.io/library/centos:7@sha256:9d4bcbbb213dfd745b58be38b13b996ebb5  0.0s
 => CACHED [2/4] WORKDIR /usr/local                                                   0.0s
 => [3/4] RUN yum -y install vim                                                     29.1s
 => [4/4] RUN yum -y install net-tools                                                2.8s
 => exporting to image                                                                2.2s 
 => => exporting layers                                                               2.2s 
 => => writing image sha256:9a4f44d6f8c3f8cb6e515e5183feb133ff89e3bc0a8b0597b5aec81f  0.0s 
 => => naming to docker.io/library/chengxcentos:1.0                                   0.0s 

**注意：**docker拉取镜像默认为最新版本。