[root@localhost ~]# docker build -t test1 .
...省略...
WARNING: IPv4 forwarding is disabled. Networking will not work.
error:xxxxxxx
...
解决办法:
在宿主机上面执行:
# net.ipv4.ip_forward=1 >> /usr/lib/sysctl.d/00-system.conf
重启network和docker服务
# systemctl restart network && systemctl restart docker
成功解决!!