1. ### Create network ns
    4. mkdir -p /var/run/netns
    6. find -L /var/run/netns -type l -delete
    9. ### Start nginx docker with non network mode
    12. docker run --network=none  -d nginx
    14. ### Check corresponding pid
    16. docker ps|grep nginx
    17. docker inspect <containerid>|grep -i pid
    19. ### Check network config for the container
    22. nsenter -t pid -n ip a
    24. ### Link network namespace
    27. export pid=pid
    28. ln -s /proc/$pid/ns/net /var/run/netns/$pid
    29. ip netns list
    32. ### Check docker bridge on the host
    34. brctl show
    36. ### Create veth pair
    39. ip link add A type veth peer name B
    42. ### Config A
    45. brctl addif docker0 A
    46. ip link set A up
    49. ### Config B
    52. SETIP=172.17.0.10
    53. SETMASK=16
    54. GATEWAY=172.17.0.1
    56. ip link set B netns $pid
    57. ip netns exec $pid ip link set dev B name eth0
    58. ip netns exec $pid ip link set eth0 up
    59. ip netns exec $pid ip addr add $SETIP/$SETMASK dev eth0
    60. ip netns exec $pid ip route add default via $GATEWAY
    63. ### Check connectivity
    66. curl 172.17.0.10