使用ip netns命令显示docker namespace 的方法

[root@docker1 bin]# vi linkns 
#!/usr/bin/bash
echo The script will link all running containers namespace into /var/run/netns, so you can use ip netns command for them.
echo Deleting all existed symbol links
rm -f /var/run/netns/*

for i in `docker container  ls | awk {'print $NF'} | grep -v NAMES`
 do
        dockerpid=`docker inspect -f {{'.State.Pid'}} $i`
        ln -s /proc/$dockerpid/ns/net /var/run/netns/$i
        echo namespace for ${i} was linked into /var/run/netns/${i}
 done

运行以上脚本即可：

[root@docker1 bin]# linkns
The script will link all running containers namespace into /var/run/netns, so you can use ip netns command for them.
Deleting all existed symbol links
namespace for busybox-2 was linked into /var/run/netns/busybox-2
namespace for busybox-1 was linked into /var/run/netns/busybox-1
[root@docker1 bin]# ip netns show
busybox-1 (id: 0)
busybox-2 (id: 1)
[root@docker1 bin]# ip netns exec busybox-1 ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.17.0.2  netmask 255.255.0.0  broadcast 0.0.0.0
        ether 02:42:ac:11:00:02  txqueuelen 0  (Ethernet)
        RX packets 16  bytes 1096 (1.0 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 4  bytes 280 (280.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        loop  txqueuelen 1  (Local Loopback)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

[root@docker1 bin]# ip netns exec busybox-2 ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.17.0.3  netmask 255.255.0.0  broadcast 0.0.0.0
        ether 02:42:ac:11:00:03  txqueuelen 0  (Ethernet)
        RX packets 15  bytes 1054 (1.0 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2  bytes 140 (140.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        loop  txqueuelen 1  (Local Loopback)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0