Docker NetWork 容器之间的link

# 安装这个包, 可以查看本机的 bridge 信息。(桥连接)

[miller@docker4 python-flask]$ sudo yum install bridge-utils

[miller@docker4 python-flask]$ brctl show
bridge name bridge id STP enabled interfaces
docker0 8000.02422dec8cee no vethddd5c78

# --link=test1  意思就是我在test2 这个容器link了test1  

# 这样在test2 容器中去 ping test1的时候, 就不需要还输入 ip。 直接通过test1 这个名字就可以了

[miller@docker4 python-flask]$ docker ps
CONTAINER ID        IMAGE                              COMMAND             CREATED             STATUS              PORTS               NAMES
3c1f23e3530e        caijiwandocker/flask-hello-world   "python3 app.py"    About an hour ago   Up About an hour    5000/tcp            test1
[miller@docker4 python-flask]$ docker run -d --name=test2 --link=test1 caijiwandocker/flask-hello-world
dc6dd83f333e2944474095f4fc76ed4465f5c938402770e45cb743fe9d60befd
[miller@docker4 python-flask]$ docker ps
CONTAINER ID        IMAGE                              COMMAND             CREATED             STATUS              PORTS               NAMES
dc6dd83f333e        caijiwandocker/flask-hello-world   "python3 app.py"    10 seconds ago      Up 8 seconds        5000/tcp            test2
3c1f23e3530e        caijiwandocker/flask-hello-world   "python3 app.py"    About an hour ago   Up About an hour    5000/tcp            test1

# 是可以通过名字访问的. 如此 如果以后要在test2上 链接 test1上的 数据库的时候, 就可以  test1:3306 就连接上了。  不关心test1的ip是多少

root@dc6dd83f333e:/app# ping test1
PING test1 (172.17.0.2) 56(84) bytes of data.
64 bytes from test1 (172.17.0.2): icmp_seq=1 ttl=64 time=0.069 ms
64 bytes from test1 (172.17.0.2): icmp_seq=2 ttl=64 time=0.085 ms
。。。

root@dc6dd83f333e:/app# ping 172.17.0.2
PING 172.17.0.2 (172.17.0.2) 56(84) bytes of data.
64 bytes from 172.17.0.2: icmp_seq=1 ttl=64 time=0.074 ms
64 bytes from 172.17.0.2: icmp_seq=2 ttl=64 time=0.091 ms
。。。

# docker network  可以自己创建一个  bridge：

[miller@docker4 python-flask]$ docker network create my-bridge
f8004079b0d715a93b2cc49c4d8f4213af8fe2e201a0d2fa547e0914cda3d784

[miller@docker4 python-flask]$ brctl show
bridge name        bridge id           STP   enabled     interfaces
br-f8004079b0d7    8000.02426a43a22c         no                        # 我自己刚刚创建的没有接口链接
docker0            8000.02422dec8cee         no          vethddd5c78   # docker0 连接着  test1 test2 两个容器
                                                         vethec36d73

[miller@docker4 python-flask]$ docker network ls
NETWORK ID          NAME                DRIVER              SCOPE
d6e9516055df        bridge              bridge              local
2d4c88aac3be        host                host                local
f8004079b0d7        my-bridge           bridge              local
8f43716b9791        none                null                local

还可以将运行中的test1 和 test2 连接到自己创建的 bridge上：

bridge name        bridge id        STP   enabled    interfaces
br-f8004079b0d7    8000.02426a43a22c      no         veth4069f1b
                                                     vetha20bc78

docker0            8000.02422dec8cee      no         vethddd5c78
                                                     vethec36d73

都连接上了, 而容器链接自己创建的 bridge 的时候, 是默认的 容器和容器之间都进行了 --link 这个操作的。

也就是说, 可以在两个容器的内部,, 只通过名字进行 ping  也可以的。

[miller@docker4 python-flask]$ docker exec -it test1 /bin/bash
root@3c1f23e3530e:/app# ping test2
PING test2 (172.18.0.3) 56(84) bytes of data.
64 bytes from test2.my-bridge (172.18.0.3): icmp_seq=1 ttl=64 time=0.100 ms
64 bytes from test2.my-bridge (172.18.0.3): icmp_seq=2 ttl=64 time=0.089 ms
.....

[miller@docker4 python-flask]$ docker exec -it test2 /bin/bash
root@dc6dd83f333e:/app# ping test1
PING test1 (172.17.0.2) 56(84) bytes of data.
64 bytes from test1 (172.17.0.2): icmp_seq=1 ttl=64 time=0.069 ms
64 bytes from test1 (172.17.0.2): icmp_seq=2 ttl=64 time=0.092 ms
......

# 使用 docker network inspace 看看 原始的 bridge 和 自己的 bridge：

[miller@docker4 python-flask]$ docker network inspect bridge 
[
   ......"Containers": {
            "3c1f23e3530eadb54eb2fc61e7e33b36627428ba25c3b037c70c8d9a5fd9954a": {
                "Name": "test1",
                "EndpointID": "555d09be7c38f0107bfbd74ce1161836dc5a6bc043fbe0e61d5bd31f3b70e90a",
                "MacAddress": "02:42:ac:11:00:02",
                "IPv4Address": "172.17.0.2/16",
                "IPv6Address": ""
            },
            "dc6dd83f333e2944474095f4fc76ed4465f5c938402770e45cb743fe9d60befd": {
                "Name": "test2",
                "EndpointID": "ed6ed94771d58b779efa46bf3aaf1d843b1b297a64086e525053db3ee811f2fd",
                "MacAddress": "02:42:ac:11:00:03",
                "IPv4Address": "172.17.0.3/16",
                "IPv6Address": ""
            }
        },
      .....
]

[miller@docker4 python-flask]$ docker network inspect my-bridge 
[
    ...."Containers": {
            "3c1f23e3530eadb54eb2fc61e7e33b36627428ba25c3b037c70c8d9a5fd9954a": {
                "Name": "test1",
                "EndpointID": "5e443196f92b1d88cbd057e80adb01ee9dca1b9f3d56307701e6df924ee1ecf6",
                "MacAddress": "02:42:ac:12:00:02",
                "IPv4Address": "172.18.0.2/16",
                "IPv6Address": ""
            },
            "dc6dd83f333e2944474095f4fc76ed4465f5c938402770e45cb743fe9d60befd": {
                "Name": "test2",
                "EndpointID": "3f6e3d84608062869bf79bc999382db52187ad28c780724f3efecf62cd0b9eb6",
                "MacAddress": "02:42:ac:12:00:03",
                "IPv4Address": "172.18.0.3/16",
                "IPv6Address": ""
            }
        },
....
]

可以看出 test1  和 test2 两个容器, 依然分别连接着两个不同的 bridge.

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