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: <LOOPBACK,UP,LOWER_UP> 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: <BROADCAST,MULTICAST,UP,LOWER_UP> 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: <NO-CARRIER,BROADCAST,MULTICAST,UP> 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: <LOOPBACK,UP,LOWER_UP> 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: <BROADCAST,MULTICAST,UP,LOWER_UP> 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: <BROADCAST,MULTICAST> 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: <LOOPBACK,UP,LOWER_UP> 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: <BROADCAST,MULTICAST,UP,LOWER_UP> 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: <LOOPBACK,UP,LOWER_UP> 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: <BROADCAST,MULTICAST,UP,LOWER_UP> 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: <NO-CARRIER,BROADCAST,MULTICAST,UP> 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: <LOOPBACK,UP,LOWER_UP> 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: <BROADCAST,MULTICAST,UP,LOWER_UP> 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: <NO-CARRIER,BROADCAST,MULTICAST,UP> 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: <LOOPBACK,UP,LOWER_UP> 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: <BROADCAST,MULTICAST,UP,LOWER_UP> 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: <BROADCAST,MULTICAST,UP,LOWER_UP> 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: <BROADCAST,MULTICAST,UP,LOWER_UP> 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           <bridge>                add bridge
        delbr           <bridge>                delete bridge
        addif           <bridge> <device>       add interface to bridge
        delif           <bridge> <device>       delete interface from bridge
        hairpin         <bridge> <port> {on|off}        turn hairpin on/off
        setageing       <bridge> <time>         set ageing time
        setbridgeprio   <bridge> <prio>         set bridge priority
        setfd           <bridge> <time>         set bridge forward delay
        sethello        <bridge> <time>         set hello time
        setmaxage       <bridge> <time>         set max message age
        setpathcost     <bridge> <port> <cost>  set path cost
        setportprio     <bridge> <port> <prio>  set port priority
        show            [ <bridge> ]            show a list of bridges
        showmacs        <bridge>                show a list of mac addrs
        showstp         <bridge>                show bridge stp info
        stp             <bridge> {on|off}       turn stp on/off
```