六、Docker网络-创建和使用自定义Bridge - 图1

docker网络的创建

  • docker network create [options]
    参数：-d：指定driver，如bridge
    例子：docker network create -d bridge mybridge

    1. [root@localhost ~]# docker network create -d bridge mybridge
    2. a0bc67bd61e96496569fe5cb99cf3541a94fb5344ab78744d017ce68b08e56de
    3. [root@localhost ~]#
    4. [root@localhost ~]# docker network ls
    5. NETWORK ID     NAME       DRIVER    SCOPE
    6. c4b678a93972   bridge     bridge    local
    7. d0763579887a   host       host      local
    8. a0bc67bd61e9   mybridge   bridge    local
    9. 6a03d63270a6   none       null      local
    10. [root@localhost ~]#
    11. [root@localhost ~]# docker network inspect a0b
    12. [
    13. {
    14. "Name": "mybridge",
    15. "Id": "a0bc67bd61e96496569fe5cb99cf3541a94fb5344ab78744d017ce68b08e56de",
    16. "Created": "2021-12-12T15:39:11.777904385+08:00",
    17. "Scope": "local",
    18. "Driver": "bridge",
    19. "EnableIPv6": false,
    20. "IPAM": {
    21. "Driver": "default",
    22. "Options": {},
    23. "Config": [
    24. {
    25. "Subnet": "172.18.0.0/16",
    26. "Gateway": "172.18.0.1"
    27. }
    28. ]
    29. },
    30. "Internal": false,
    31. "Attachable": false,
    32. "Ingress": false,
    33. "ConfigFrom": {
    34. "Network": ""
    35. },
    36. "ConfigOnly": false,
    37. "Containers": {},
    38. "Options": {},
    39. "Labels": {}
    40. }
    41. ]

  • 可看到新创建的bridge子网为172.18.0.0/16

    使用自定义bridge

  • 创建container时使用--network [network_name] 来指定网络

    1. [root@localhost ~]# docker container run -d --name box3 --network mybridge busybox /bin/sh -c "while true; do sleep 3600; done"
    2. d4d224ad1847593352e11877e2264797129c3205d13aae42c227c50fea6b903a
    3. [root@localhost ~]#
    4. [root@localhost ~]# docker container ls
    5. CONTAINER ID   IMAGE     COMMAND                  CREATED          STATUS          PORTS     NAMES
    6. d4d224ad1847   busybox   "/bin/sh -c 'while t…"   11 seconds ago   Up 10 seconds             box3
    7. a99bb30012ad   busybox   "/bin/sh -c 'while t…"   19 hours ago     Up 19 hours               box2
    8. 80c4a01d050e   busybox   "/bin/sh -c 'while t…"   19 hours ago     Up 19 hours               box1

  • 使用docker container inspect box3查看容器信息，发现网络使用的是自定义的bridge
    六、Docker网络-创建和使用自定义Bridge - 图2

  • 使用docker network inspect mybridge 查看自定义的bridge信息，发现container下有box3
    六、Docker网络-创建和使用自定义Bridge - 图3

    自定义网络提供类似DNS功能

  • 使用docker network connect bridge box3 来使容器box3连接默认的bridge网络

  • 连接完成后docker container inspect box3 来查看box3的信息，发现box3同时连接了自定义的mybridge和默认的bridge
    六、Docker网络-创建和使用自定义Bridge - 图4

  • 进入到容器中docker container exec -it box3 sh查看ip信息ip a，也能查看到此容器连接了172.18.0.2/16以及172.17.0.4/16两个接口

    1. [root@localhost ~]# docker container exec -it box3 sh
    2. / # ip a
    3. 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    4.   link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    5.   inet 127.0.0.1/8 scope host lo
    6.      valid_lft forever preferred_lft forever
    7. 29: eth0@if30: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue
    8.   link/ether 02:42:ac:12:00:02 brd ff:ff:ff:ff:ff:ff
    9.   inet 172.18.0.2/16 brd 172.18.255.255 scope global eth0
    10.      valid_lft forever preferred_lft forever
    11. 31: eth1@if32: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue
    12.   link/ether 02:42:ac:11:00:04 brd ff:ff:ff:ff:ff:ff
    13.   inet 172.17.0.4/16 brd 172.17.255.255 scope global eth1
    14.      valid_lft forever preferred_lft forever

  • 使用docker network inspect bridge也能查看到container中多了box3这个容器
    六、Docker网络-创建和使用自定义Bridge - 图5

    关闭网络连接

  • docker network disconnect [network_name] [container_name]

    容器网络互通实验

  1. 创建第四个容器box4，网络连接至mybridge：docker container run -d --name box4 --network mybridge busybox /bin/sh -c "while true; do sleep 3600; done"

  2. 查看box3和box4的网络连接

    1. [root@localhost ~]# docker container exec -it box3 ip a
    2. 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    3.  link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    4.  inet 127.0.0.1/8 scope host lo
    5.     valid_lft forever preferred_lft forever
    6. 29: eth0@if30: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue
    7.  link/ether 02:42:ac:12:00:02 brd ff:ff:ff:ff:ff:ff
    8.  inet 172.18.0.2/16 brd 172.18.255.255 scope global eth0
    9.     valid_lft forever preferred_lft forever
    10. [root@localhost ~]#
    11. [root@localhost ~]# docker container exec -it box4 ip a
    12. 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    13.  link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    14.  inet 127.0.0.1/8 scope host lo
    15.     valid_lft forever preferred_lft forever
    16. 33: eth0@if34: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue
    17.  link/ether 02:42:ac:12:00:03 brd ff:ff:ff:ff:ff:ff
    18.  inet 172.18.0.3/16 brd 172.18.255.255 scope global eth0
    19.     valid_lft forever preferred_lft forever

  3. 在box3中使用box4的ip以及名字进行网络连接（ping）
    六、Docker网络-创建和使用自定义Bridge - 图6

    Note 由此可见自定义的mybridge提供了类似DNS的功能，可以通过容器名称查询其ip地址。但是默认的bridge不提供类似的DNS的功能。 六、Docker网络-创建和使用自定义Bridge - 图7

docker network其他参数

  1. [root@localhost ~]# docker network create --help
  2. Usage:  docker network create [OPTIONS] NETWORK
  3. Create a network
  4. Options:
  5.       --attachable           Enable manual container attachment
  6.       --aux-address map      Auxiliary IPv4 or IPv6 addresses used by Network driver (default map[])
  7.       --config-from string   The network from which to copy the configuration
  8.       --config-only          Create a configuration only network
  9.   -d, --driver string        Driver to manage the Network (default "bridge")
  10.       --gateway strings      IPv4 or IPv6 Gateway for the master subnet
  11.       --ingress              Create swarm routing-mesh network
  12.       --internal             Restrict external access to the network
  13.       --ip-range strings     Allocate container ip from a sub-range
  14.       --ipam-driver string   IP Address Management Driver (default "default")
  15.       --ipam-opt map         Set IPAM driver specific options (default map[])
  16.       --ipv6                 Enable IPv6 networking
  17.       --label list           Set metadata on a network
  18.   -o, --opt map              Set driver specific options (default map[])
  19.       --scope string         Control the network's scope
  20.       --subnet strings       Subnet in CIDR format that represents a network segment
  • 指定网关和子网
    docker network create -d bridge --gateway 172.200.0.1 --subnet 172.200.0.0/16 demo-bridge
    1. [root@localhost ~]# docker network create -d bridge --gateway 172.200.0.1 --subnet 172.200.0.0/16 demo-bridge
    2. 18294d3e66dd7004ff956f8f1243ffcaf2d29940f3e024dfcd70c41814cc1b01
    3. [root@localhost ~]#
    4. [root@localhost ~]# docker network inspect demo-bridge
    5. [
    6.   {
    7.       "Name": "demo-bridge",
    8.       "Id": "18294d3e66dd7004ff956f8f1243ffcaf2d29940f3e024dfcd70c41814cc1b01",
    9.       "Created": "2021-12-12T16:19:44.154286168+08:00",
    10.       "Scope": "local",
    11.       "Driver": "bridge",
    12.       "EnableIPv6": false,
    13.       "IPAM": {
    14.           "Driver": "default",
    15.           "Options": {},
    16.           "Config": [
    17.               {
    18.                   "Subnet": "172.200.0.0/16",
    19.                   "Gateway": "172.200.0.1"
    20.               }
    21.           ]
    22.       },
    23.       "Internal": false,
    24.       "Attachable": false,
    25.       "Ingress": false,
    26.       "ConfigFrom": {
    27.           "Network": ""
    28.       },
    29.       "ConfigOnly": false,
    30.       "Containers": {},
    31.       "Options": {},
    32.       "Labels": {}
    33.   }
    34. ]