docker 网桥的管理(一)

看到docker安装启动之后出现的“网卡” docker0比较好奇，想着怎么可以把它删除。

$ ip a
1: lo:  mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether fa:16:3e:34:6f:00 brd ff:ff:ff:ff:ff:ff
    inet 172.28.32.49/24 brd 172.28.32.255 scope global dynamic eth0
       valid_lft 3151251593sec preferred_lft 3151251593sec
    inet6 fe80::f816:3eff:fe34:6f00/64 scope link
       valid_lft forever preferred_lft forever
3: docker0:  mtu 1500 qdisc noqueue state DOWN
    link/ether 02:42:89:af:c2:05 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 scope global docker0
       valid_lft forever preferred_lft forever

$ service docker stop

docker0 仍然存在。

尝试删除 docker0

$ brctl delbr docker0
bridge docker0 is still up; can't delete it

要想让 docker0 消失， 可以把该网卡停掉

$ ifconfig docker0 down

$ ip a
1: lo:  mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether fa:16:3e:34:6f:00 brd ff:ff:ff:ff:ff:ff
    inet 172.28.32.49/24 brd 172.28.32.255 scope global dynamic eth0
       valid_lft 3151224228sec preferred_lft 3151224228sec
    inet6 fe80::f816:3eff:fe34:6f00/64 scope link
       valid_lft forever preferred_lft forever
3: docker0:  mtu 1500 qdisc noqueue state DOWN
    link/ether 02:42:89:af:c2:05 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 scope global docker0
       valid_lft forever preferred_lft forever

$  brctl delbr docker0

查看ifconfig, 发现 docker0消失了。

$  ip a
1: lo:  mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether fa:16:3e:34:6f:00 brd ff:ff:ff:ff:ff:ff
    inet 172.28.32.49/24 brd 172.28.32.255 scope global dynamic eth0
       valid_lft 3151224188sec preferred_lft 3151224188sec
    inet6 fe80::f816:3eff:fe34:6f00/64 scope link
       valid_lft forever preferred_lft forever



$ service docker restart
Redirecting to /bin/systemctl restart  docker.service

$ ip a
1: lo:  mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether fa:16:3e:34:6f:00 brd ff:ff:ff:ff:ff:ff
    inet 172.28.32.49/24 brd 172.28.32.255 scope global dynamic eth0
       valid_lft 3151224029sec preferred_lft 3151224029sec
    inet6 fe80::f816:3eff:fe34:6f00/64 scope link
       valid_lft forever preferred_lft forever
4: docker0:  mtu 1500 qdisc noqueue state DOWN
    link/ether 02:42:02:5d:b4:26 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 scope global docker0
       valid_lft forever preferred_lft forever

$ ifconfig docker0 up
$ ip a
1: lo:  mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether fa:16:3e:34:6f:00 brd ff:ff:ff:ff:ff:ff
    inet 172.28.32.49/24 brd 172.28.32.255 scope global dynamic eth0
       valid_lft 3151224003sec preferred_lft 3151224003sec
    inet6 fe80::f816:3eff:fe34:6f00/64 scope link
       valid_lft forever preferred_lft forever
4: docker0:  mtu 1500 qdisc noqueue state DOWN
    link/ether 02:42:02:5d:b4:26 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 scope global docker0
       valid_lft forever preferred_lft forever

启动一个 ubuntu的镜像：

$ docker run -it ubuntu bash
Unable to find image 'ubuntu:latest' locally
Trying to pull repository docker.io/library/ubuntu ...
latest: Pulling from docker.io/library/ubuntu
d5c6f90da05d: Pull complete
1300883d87d5: Pull complete
c220aa3cfc1b: Pull complete
2e9398f099dc: Pull complete
dc27a084064f: Pull complete
Digest: sha256:47716ab73252837a8bae20dcedfe86087fa71bb7d3c339160731b3d0aacb5d7b

查看docker的进程：

$ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
3b9feedd7651        ubuntu              "bash"              3 minutes ago       Up 3 minutes

查看 ipconfig:

$ ip a
1: lo:  mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether fa:16:3e:34:6f:00 brd ff:ff:ff:ff:ff:ff
    inet 172.28.32.49/24 brd 172.28.32.255 scope global dynamic eth0
       valid_lft 3151223622sec preferred_lft 3151223622sec
    inet6 fe80::f816:3eff:fe34:6f00/64 scope link
       valid_lft forever preferred_lft forever
4: docker0:  mtu 1500 qdisc noqueue state UP
    link/ether 02:42:02:5d:b4:26 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:2ff:fe5d:b426/64 scope link
       valid_lft forever preferred_lft forever
10: veth655cca0@if9:  mtu 1500 qdisc noqueue master docker0 state UP
    link/ether ae:1b:6d:ab:94:5b brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::ac1b:6dff:feab:945b/64 scope link
       valid_lft forever preferred_lft forever

扩展阅读：
===========
```
$ brctl --help
Usage: brctl [commands]
commands:
        addbr                           add bridge
        delbr                           delete bridge
        addif                   add interface to bridge
        delif                   delete interface from bridge
        hairpin           {on|off}        turn hairpin on/off
        setageing                 set ageing time
        setbridgeprio             set bridge priority
        setfd                     set bridge forward delay
        sethello                  set hello time
        setmaxage                 set max message age
        setpathcost         set path cost
        setportprio         set port priority
        show            [  ]            show a list of bridges
        showmacs                        show a list of mac addrs
        showstp                         show bridge stp info
        stp              {on|off}       turn stp on/off
```