Docker网络

mount 命令查看挂载信息

• /etc/hosts, /etc/hostname, /etc/resolve.conf 是临时的，只是在运行容器时保留，docker commit不会被提交

root@gitlab:/# mount |grep "/etc" 
/dev/vdb1 on /etc/gitlab type ext4 (rw,relatime,data=ordered)
/dev/vda1 on /etc/resolv.conf type ext4 (rw,relatime,data=ordered) 
/dev/vda1 on /etc/hostname type ext4 (rw,relatime,data=ordered) 
/dev/vda1 on /etc/hosts type ext4 (rw,relatime,data=ordered) 

检查容器访问外部网络

• 在宿主机Linux中检测转发是否打开

$ sudo sysctl net.ipv4.ip_forward
net.ipv4.ip_forward = 1
$ sudo sysctl -w net.ipv4.ip_forward=1  # 打开

查看宿主机nat表上POSTROUTING链规则

iptables -t nat -nvL POSTROUTING

Docker自定义网桥

• 默认docker0网桥，在Docker服务启动时可以使用-b BRIDGE 来指定使用的网桥

- 停止docker服务,删除docker0网桥
$ systemctl stop docker
$ ip link set dev docker0 down
$ brctl delbr docker0

- 创建一个网桥bridge0
$ brctl addbr bridge0
$ ip addr add 192.168.5.1/24 dev bridge0
$ ip link set dev bridge0 up

- 查看网桥并启动
$ ip addr show bridge0
$ echo 'DOCKER_OPTS="-b=bridge0"' >> /etc/defalut/docker
$ sudo systemctl start docker