①故障现象
场景:基于 Dockerfile 创建一个最基本的 httpd 镜像
报错代码如下:
[root@localhost ~]docker build -t httpd:centos .
...
...
Step 3/9 : RUN yum -y update
---> [Warning] IPv4 forwarding is disabled. Networking will not work.
---> Running in a0a858748903
CentOS Linux 8 - AppStream 0.0 B/s | 0 B 04:00
Errors during downloading metadata for repository