docker--container之间的link,bridge create

container的name和ID一样，也是唯一的，当不知道container的IP时，可以用name替代，但需要先配置link

下面创建两个container 时，未配置link所以ping name 不通。

[root@localhost ~]# docker container ls
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES
f81ab807503c        busybox             "/bin/sh -c 'while t…"   5 hours ago         Up 5 hours                              test2
cba625871070        busybox             "/bin/sh -c 'while t…"   5 hours ago         Up 5 hours                              test1
[root@localhost ~]# docker exec test1 ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue 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
18: eth0@if19: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.2/16 brd 172.17.255.255 scope global eth0
       valid_lft forever preferred_lft forever
[root@localhost ~]# docker exec test2 ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue 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
20: eth0@if21: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:ac:11:00:03 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.3/16 brd 172.17.255.255 scope global eth0
       valid_lft forever preferred_lft forever
[root@localhost ~]# docker exec test1 ping 172.17.0.3
PING 172.17.0.3 (172.17.0.3): 56 data bytes
64 bytes from 172.17.0.3: seq=0 ttl=64 time=0.074 ms
64 bytes from 172.17.0.3: seq=1 ttl=64 time=0.114 ms
^C
[root@localhost ~]# docker exec test1 ping test2


^C
[root@localhost ~]# docker exec test2 ping 172.17.0.2
PING 172.17.0.2 (172.17.0.2): 56 data bytes
64 bytes from 172.17.0.2: seq=0 ttl=64 time=0.077 ms
64 bytes from 172.17.0.2: seq=1 ttl=64 time=0.100 ms
^C
[root@localhost ~]# docker exec test2 ping test1


^C
[root@localhost ~]# 

把test2删了重下创建，并指定link，link具有单向性

[root@localhost ~]# docker stop test2
test2
[root@localhost ~]# docker rm test2
test2
[root@localhost ~]#
[root@localhost ~]# docker run --name test2 -d --link test1  busybox /bin/sh -c "while true;do sleep 3600;done"
WARNING: IPv4 forwarding is disabled. Networking will not work.
68789fa4dc47ce821337c64898c11693e24dcc47ff06641e89feabd9a7ffe21d
[root@localhost ~]# docker exec test2 ping test1
PING test1 (172.17.0.2): 56 data bytes
64 bytes from 172.17.0.2: seq=0 ttl=64 time=0.073 ms
64 bytes from 172.17.0.2: seq=1 ttl=64 time=0.071 ms
64 bytes from 172.17.0.2: seq=2 ttl=64 time=0.071 ms
^C
[root@localhost ~]# docker exec test1 ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue 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
18: eth0@if19: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.2/16 brd 172.17.255.255 scope global eth0
       valid_lft forever preferred_lft forever
[root@localhost ~]# docker exec test2 ping 172.17.0.2
PING 172.17.0.2 (172.17.0.2): 56 data bytes
64 bytes from 172.17.0.2: seq=0 ttl=64 time=0.076 ms
64 bytes from 172.17.0.2: seq=1 ttl=64 time=0.161 ms
^C
[root@localhost ~]# docker exec test2 ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue 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
22: eth0@if23: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:ac:11:00:03 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.3/16 brd 172.17.255.255 scope global eth0
       valid_lft forever preferred_lft forever
[root@localhost ~]# docker exec test1 ping 172.17.0.3
PING 172.17.0.3 (172.17.0.3): 56 data bytes
64 bytes from 172.17.0.3: seq=0 ttl=64 time=0.087 ms
64 bytes from 172.17.0.3: seq=1 ttl=64 time=0.085 ms
^C
[root@localhost ~]# docker exec test1 ping test2


^C
[root@localhost ~]# 

创建bridge

[root@localhost ~]# docker network ls
NETWORK ID          NAME                DRIVER              SCOPE
4e8172ef8e01        bridge              bridge              local
9e8c9ce3e33b        host                host                local
6d01f937585b        none                null                local
[root@localhost ~]# docker network create -d bridge my-bridge
b190bd600feb9ab1293e882b4b5c5b828ab4dda1215fd25e9a1921ac8e2f2f07
[root@localhost ~]# docker network ls
NETWORK ID          NAME                DRIVER              SCOPE
4e8172ef8e01        bridge              bridge              local
9e8c9ce3e33b        host                host                local
b190bd600feb        my-bridge           bridge              local
6d01f937585b        none                null                local
[root@localhost ~]# 

create container 并指定docker network

[root@localhost ~]# brctl show #br-b190bd600feb即刚才create的my-bridge
bridge name    bridge id        STP enabled    interfaces
br-b190bd600feb        8000.0242e6e2a884    no        
docker0        8000.0242e850c76c    no        veth59c00fa
                            vethfdefc77
virbr0        8000.525400105abe    yes        virbr0-nic
[root@localhost ~]# docker run -d --name test3 --network my-bridge busybox /bin/sh -c "while true;do sleep 3600;done" #增加network参数
WARNING: IPv4 forwarding is disabled. Networking will not work.
cec10f0cd32dc6c059bf29173572a34d0d41c2ff5602d0b8ccac0032a4ac2911
[root@localhost ~]# brctl show
bridge name    bridge id        STP enabled    interfaces
br-b190bd600feb        8000.0242e6e2a884    no        veth75fc0ca
docker0        8000.0242e850c76c    no        veth59c00fa
                            vethfdefc77
virbr0        8000.525400105abe    yes        virbr0-nic
[root@localhost ~]#

 再create container 网络连接my-bridge

[root@localhost ~]# docker run -d --name test4 --network my-bridge busybox /bin/sh -c "while true;do sleep 3600;done"
WARNING: IPv4 forwarding is disabled. Networking will not work.
19216c85489ee71d68bff33ff1ce64a6aff4f035e91659acd08ec9349e3440f3
[root@localhost ~]# docker network inspect my-bridge
[
    {
        "Name": "my-bridge",
        "Id": "b190bd600feb9ab1293e882b4b5c5b828ab4dda1215fd25e9a1921ac8e2f2f07",
        "Created": "2019-07-18T20:11:48.739837987-07:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "172.18.0.0/16",
                    "Gateway": "172.18.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "19216c85489ee71d68bff33ff1ce64a6aff4f035e91659acd08ec9349e3440f3": {
                "Name": "test4",
                "EndpointID": "9411999854b328be4ad2362a38967f770635bfda8cbf34190e0a61fad83bd815",
                "MacAddress": "02:42:ac:12:00:03",
                "IPv4Address": "172.18.0.3/16",
                "IPv6Address": ""
            },
            "cec10f0cd32dc6c059bf29173572a34d0d41c2ff5602d0b8ccac0032a4ac2911": {
                "Name": "test3",
                "EndpointID": "e6470a84504340d4668c0c66b6c4d068898ac9c177e0caf51d8869198349f84a",
                "MacAddress": "02:42:ac:12:00:02",
                "IPv4Address": "172.18.0.2/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {}
    }
]
[root@localhost ~]#

同个bridge同网段，能ping通，不同bridge不同网段，不能ping通

[root@localhost ~]# docker exec test3 ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue 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
25: eth0@if26: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:ac:12:00:02 brd ff:ff:ff:ff:ff:ff
    inet 172.18.0.2/16 brd 172.18.255.255 scope global eth0
       valid_lft forever preferred_lft forever
[root@localhost ~]# docker exec test4 ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue 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
27: eth0@if28: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:ac:12:00:03 brd ff:ff:ff:ff:ff:ff
    inet 172.18.0.3/16 brd 172.18.255.255 scope global eth0
       valid_lft forever preferred_lft forever
[root@localhost ~]# docker exec test3 ping 172.18.0.3
PING 172.18.0.3 (172.18.0.3): 56 data bytes
64 bytes from 172.18.0.3: seq=0 ttl=64 time=0.077 ms
64 bytes from 172.18.0.3: seq=1 ttl=64 time=0.138 ms
^C
[root@localhost ~]# 
[root@localhost ~]# docker exec test3 ping 172.17.0.3


^C
[root@localhost ~]# 

如果container是在用户自定义的bridge上，则默认是link的

[root@localhost ~]# docker exec test3 ping test4
PING test4 (172.18.0.3): 56 data bytes
64 bytes from 172.18.0.3: seq=0 ttl=64 time=0.042 ms
64 bytes from 172.18.0.3: seq=1 ttl=64 time=0.149 ms
^C
[root@localhost ~]# docker exec test4 ping test3
PING test3 (172.18.0.2): 56 data bytes
64 bytes from 172.18.0.2: seq=0 ttl=64 time=0.060 ms
64 bytes from 172.18.0.2: seq=1 ttl=64 time=0.065 ms
^C
[root@localhost ~]# 

如果把别的bridge也连接到用户创建的bridge上，那也是默认link上的

[root@localhost ~]# docker network connect my-bridge test1
[root@localhost ~]# docker network inspect 
bridge     host       my-bridge  none       
[root@localhost ~]# docker network inspect my-bridge 
[
    {
        "Name": "my-bridge",
        "Id": "b190bd600feb9ab1293e882b4b5c5b828ab4dda1215fd25e9a1921ac8e2f2f07",
        "Created": "2019-07-18T20:11:48.739837987-07:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "172.18.0.0/16",
                    "Gateway": "172.18.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "19216c85489ee71d68bff33ff1ce64a6aff4f035e91659acd08ec9349e3440f3": {
                "Name": "test4",
                "EndpointID": "9411999854b328be4ad2362a38967f770635bfda8cbf34190e0a61fad83bd815",
                "MacAddress": "02:42:ac:12:00:03",
                "IPv4Address": "172.18.0.3/16",
                "IPv6Address": ""
            },
            "cba62587107007983d45a4383598dbec18a37d33e415f2325572e8f98f36a32a": {
                "Name": "test1",
                "EndpointID": "2b5c94ee7d8f5c76ae531e023190528e16cf18f3291298610f3b601511130c32",
                "MacAddress": "02:42:ac:12:00:04",
                "IPv4Address": "172.18.0.4/16",
                "IPv6Address": ""
            },
            "cec10f0cd32dc6c059bf29173572a34d0d41c2ff5602d0b8ccac0032a4ac2911": {
                "Name": "test3",
                "EndpointID": "e6470a84504340d4668c0c66b6c4d068898ac9c177e0caf51d8869198349f84a",
                "MacAddress": "02:42:ac:12:00:02",
                "IPv4Address": "172.18.0.2/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {}
    }
]
[root@localhost ~]# docker exec test4 ping test1
PING test1 (172.18.0.4): 56 data bytes
64 bytes from 172.18.0.4: seq=0 ttl=64 time=0.082 ms
64 bytes from 172.18.0.4: seq=1 ttl=64 time=0.170 ms
^C
[root@localhost ~]#