Docker 容器互联 --link 和自定义网络

鳄鱼儿

发布于 2024-05-22 09:09:08

730

发布于 2024-05-22 09:09:08

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--link

docker run -d -P --name mytomcat01 tomcat
# mytomcat02容器通过 --link 连接mytomcat01
docker run -d -P --name mytomcat02 --link mytomcat01 tomcat

测试

docker exec -it mytomcat02 ping mytomcat01
docker exec -it mytomcat01 ping mytomcat02

在使用mytomcat02 连通 mytomcat01测试是没有问题的，而mytomcat01 连通 mytomcat02是不行的。

自定义网络

查看所有的docker网络

网络模式

bridge：桥接，docker默认的模式
none：不配置网络
host：和宿主机共享网络
container：容器内网络连通（用得少，局限性很大）

# docker默认启动容器网络 --net bridge
docker run -d -P --name mytomcat tomcat
docker run -d -P --name mytomcat --net bridge tomcat

创建自定义网络

使用bridge桥接模式
子网掩码192.168.0.0/16
网关192.1678.0.1
设置自定义网络名称为mynet

docker network create --driver bridge --subnet 192.168.0.0/16 --gateway 192.168.0.1 mynet

查看所有的docker网络，可以看到新定义的mynet网络规则

docker network ls

查看自定义网络mynet的详细配置

docker network inspect mynet

使用自定义网络进行测试

启动两个tomcat容器进行网络测试

docker run -d -P --name mytomcat01 --net mynet tomcat
docker run -d -P --name mytomcat02 --net mynet tomcat

再次查看自定义网络，会发现启动的两个tomcat容器分别占用了192.168.0.2和192.168.0.3。

[root@berbai01 ~]# docker network inspect mynet
[
    {
        "Name": "mynet",
        "Id": "d20f927dca673bfed0171621dbaa7a188e1ace53527254fafd563b84a9b4b126",
        "Created": "2021-08-28T16:10:48.145033744+08:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "192.168.0.0/16",
                    "Gateway": "192.168.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "47cc0d4b74a1102fde953848139f6861e35d4d82ac54a676631c4b15bd8edfae": {
                "Name": "mytomcat01",
                "EndpointID": "023dff7f5fd886722583cae01182d0d864e3af645cfbdbccbd7d74b74edd0cf6",
                "MacAddress": "02:42:c0:a8:00:02",
                "IPv4Address": "192.168.0.2/16",
                "IPv6Address": ""
            },
            "a1c5e80a0a09acb38eb07e6abdca6e4d85c0c5da9ee773e69201ff14d43e337b": {
                "Name": "mytomcat02",
                "EndpointID": "e2a8ada261cccbed8f84ade28c4f390f73643a7236e958be560eaf0c1bf947c8",
                "MacAddress": "02:42:c0:a8:00:03",
                "IPv4Address": "192.168.0.3/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {}
    }
]

测试两个容器的网络连通情况

# 通过容器的ip访问
docker exec -it mytomcat01 ping 192.168.0.3
# 通过容器名访问
docker exec -it mytomcat01 ping mytomcat02
docker exec -it mytomcat02 ping mytomcat01

两者都会可以连通的

小结

docker使用自定义网络，可以自动实现容器的互联。 使用自定义网络的优势：在搭建集群时，可以根据不同的集群使用不同的网络，保证集群是安全和健康的

不同网络的连通

连通所使用的指令

docker network connect [OPTIONS] NETWORK CONTAINER

用默认bridge模式和自定义mynet模式进行测试

# 默认bridge模式运行
docker run -d -P --name tomcat01 tomcat
docker run -d -P --name tomcat02 tomcat
# 自定义mynet模式运行
docker run -d -P --name tomcatmynet01 --net mynet tomcat

先测试tomcat01和tomcat02能不能连通tomcatmynet01

docker exec -it tomcat01 ping tomcatmynet01
docker exec -it tomcat02 ping tomcatmynet01

显然是不能连通的。

查看bridge模式和mynet模式的配置

docker network inspect bridge
docker network inspect mynet

bridge模式网段是171.17.0.0/16 mynet模式网段是192.168.0.0/16 学过网络原理的同学都知道不同网段是不能进行连通的。

[root@berbai01 ~]# docker network inspect bridge
[
    {
        "Name": "bridge",
        "Id": "1f223afddbadd639a936453c1eb184edf9f6ae9219e31babd69e240a39f5c195",
        "Created": "2021-08-28T16:28:14.602655353+08:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.17.0.0/16",
                    "Gateway": "172.17.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "76c15c6238d6485d5379624300d4ea7f3796ead8f7df5ac38e29029ab7892d3a": {
                "Name": "tomcat01",
                "EndpointID": "63cb04611404ba6668319d76af24f12830b7db09a597a625ad88f60b576af1ff",
                "MacAddress": "02:42:ac:11:00:02",
                "IPv4Address": "172.17.0.2/16",
                "IPv6Address": ""
            },
            "b7cd5d28c3a6388cae45da8d1399ddf22a303a1f5899efaa673290c3a411cc32": {
                "Name": "tomcat02",
                "EndpointID": "57dc989fb590b9431ae9aed7b291362c224e11ad1f861e7e84bd859f1b5589e9",
                "MacAddress": "02:42:ac:11:00:03",
                "IPv4Address": "172.17.0.3/16",
                "IPv6Address": ""
            }
        },
        "Options": {
            "com.docker.network.bridge.default_bridge": "true",
            "com.docker.network.bridge.enable_icc": "true",
            "com.docker.network.bridge.enable_ip_masquerade": "true",
            "com.docker.network.bridge.host_binding_ipv4": "0.0.0.0",
            "com.docker.network.bridge.name": "docker0",
            "com.docker.network.driver.mtu": "1500"
        },
        "Labels": {}
    }
]
[root@berbai01 ~]#
[root@berbai01 ~]# docker network inspect mynet
[
    {
        "Name": "mynet",
        "Id": "d20f927dca673bfed0171621dbaa7a188e1ace53527254fafd563b84a9b4b126",
        "Created": "2021-08-28T16:10:48.145033744+08:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "192.168.0.0/16",
                    "Gateway": "192.168.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "f554e062918dc35ac7e1ce858b7cb9fc9e5f0a7eaadc90bdce8fdaad00b9b1ae": {
                "Name": "tomcatmynet01",
                "EndpointID": "3e4b65c4826425e1d11397544055e0aa33cf113ccf7045f9c20b866ba6a5cdb3",
                "MacAddress": "02:42:c0:a8:00:02",
                "IPv4Address": "192.168.0.2/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {}
    }
]
[root@berbai01 ~]#

建立bride模式容器与mynet模式容器的连接

docker network connect mynet tomcat01
# 再次查看mynet配置
docker network inspect mynet

这里发现tomcat01也加入了mynet网络中，说明tomcat01容器已经可以与mynet网络中容器连通。下面通过测试也可以得知。

[root@berbai01 ~]# docker network inspect mynet
[
    {
        "Name": "mynet",
        "Id": "d20f927dca673bfed0171621dbaa7a188e1ace53527254fafd563b84a9b4b126",
        "Created": "2021-08-28T16:10:48.145033744+08:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "192.168.0.0/16",
                    "Gateway": "192.168.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "76c15c6238d6485d5379624300d4ea7f3796ead8f7df5ac38e29029ab7892d3a": {
                "Name": "tomcat01",
                "EndpointID": "0852fbe26a3d37668c2deff948671bc6a52749068f518104f99e8ad5ad3d7057",
                "MacAddress": "02:42:c0:a8:00:03",
                "IPv4Address": "192.168.0.3/16",
                "IPv6Address": ""
            },
            "f554e062918dc35ac7e1ce858b7cb9fc9e5f0a7eaadc90bdce8fdaad00b9b1ae": {
                "Name": "tomcatmynet01",
                "EndpointID": "3e4b65c4826425e1d11397544055e0aa33cf113ccf7045f9c20b866ba6a5cdb3",
                "MacAddress": "02:42:c0:a8:00:02",
                "IPv4Address": "192.168.0.2/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {}
    }
]
[root@berbai01 ~]#

再次测试tomcat01与tomcatmynet01的连通

docker exec -it tomcat01 ping tomcatmynet01

经测试tomcat01已经可以与tomcatmynet01进行连通

tomcat02与tomcatmynet01的连通情况呢？

docker exec -it tomcat02 ping tomcatmynet01

可以看到如果没有与mynet进行connect，是不能进行连通的

小结

docker容器的网络互通其实就是赋予了一个容器多个ip，如上述试验中tomcat01被新赋予了ip192.168.0.3，于是tomcat01可以完成与mynet网络中容器进行连通。而tomcat02并没有与mynet进行connect连接，没有与mynet相同的网段地址，依然不能与mynet中容器进行连通。

本文参与腾讯云自媒体同步曝光计划，分享自作者个人站点/博客。

原始发表：2024-05-21，如有侵权请联系 cloudcommunity@tencent.com 删除

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