参考：
https://www.runoob.com/docker/docker-container-connection.html
ubuntu 的镜像没有自带ping，所以自己pull busybox
docker pull busybox
新建网络
docker network create -d bridge test-net
连接容器
运行一个容器并连接到新建的 test-net 网络:
docker run -itd --name test1 --network test-net busybox /bin/sh
docker run -itd --name test2 --network test-net busybox /bin/sh
互相ping测试
docker exec -it test1 ping test2
PING test2 (192.168.48.3): 56 data bytes
64 bytes from 192.168.48.3: seq=0 ttl=64 time=0.084 ms
docker exec -it test2 ping test1
PING test1 (192.168.48.2): 56 data bytes
64 bytes from 192.168.48.2: seq=0 ttl=64 time=0.060 ms