其它网络下的容器加入mynet网络，实现一个容器两个ip地址

网络集群

先创建test-network网络：
docker network create test-network
再运行centos01容器并加入到test-network网络下
docker run -it -P --name centos01 --net test-network centos
centos01容器已经加入在test-network网络下了

centos01加入mynet网络
root@--- ~]# docker network connect mynet centos01
查看mynet网络
docker network ls
[root@--- ~]# docker network ls
NETWORK ID     NAME           DRIVER    SCOPE
feafa30d4051   bridge         bridge    local
e8bf4fced9e2   host           host      local
0096a971fd2c   mynet          bridge    local  # 自定义bridge网桥
6263db0933b9   none           null      local
799426d70aa2   test-network   bridge    local
docker network inspect 0096
[root@--- ~]# docker network inspect 0096
[
    {
        "Name": "mynet",
        "Id": "0096a971fd2c66400e53cbae5e53eceedc2f90d5685917e9534640a3535c0ef1",
        "Created": "2021-10-04T10:18:09.113847736+08:00",
        # ... 省略代码展示
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "192.168.0.0/16",
                    "Gateway": "192.168.0.1"
                }
            ]
        },
        # ... 省略代码展示
        "Containers": {
            "2fac920eebd505794c4a27ef4efdf531d32805e8663bded93a473bd28236bc27": {
                "Name": "mynet-centos01",
                "EndpointID": "3aff075...",
                "MacAddress": "02:42:c0:a8:00:02",
                "IPv4Address": "192.168.0.2/16",
                "IPv6Address": ""
            },
            "3dceda051252b6970fe2156bac7710ba6489a97aac68c49b1c85a2f130d0556f": {
                "Name": "mynet-tomcat01",
                "EndpointID": "9f52b19...",
                "MacAddress": "02:42:c0:a8:00:03",
                "IPv4Address": "192.168.0.3/16",
                "IPv6Address": ""
            },
            "cb1922b95b9316d129b54f3545fad9729092926e10a1d5517f8928db42706151": {
                "Name": "centos01",
                "EndpointID": "0ba2107...",
                "MacAddress": "02:42:c0:a8:00:04",
                "IPv4Address": "192.168.0.4/16",   # 新加入的centos01容器
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {}
    }
]
查看centos01的容器信息
可以看到Networks下面存在mynet、test-network两个网络连接信息

一个容器两个ip地址

无关代码已省略展示

[root@--- ~]# docker inspect cb19
[
    {
        "Id": "cb1922b95b9316d129b54f3545fad9729092926e10a1d5517f8928db42706151",
        "Created": "2021-10-03T13:39:00.942877668Z",
        "Path": "/bin/bash",
        "Args": [],
        
        # ... 省略代码展示
        
        "NetworkSettings": {
            # ... 省略代码展示
            "Networks": {
                # 网络连接1 ： mynet
                "mynet": {、
                    # ... 省略代码展示
                    "Gateway": "192.168.0.1",
                    "IPAddress": "192.168.0.4",
                    "MacAddress": "02:42:c0:a8:00:04",
                },
                # 网络连接2 ： test-network
                "test-network": {
                    # ... 省略代码展示
                    "Gateway": "172.18.0.1",
                    "IPAddress": "172.18.0.3",
                    "MacAddress": "02:42:ac:12:00:03",
                }
            }
        }
    }
]
test-network网卡下的centos01访问mynet网卡下的mynet-centos01、mynet-tomcat01
容器ip和容器名都可以连接

进入centos01容器
[root@--- ~]# docker exec -it cb19 /bin/bash
mynet-tomcat01 容器的IP是: 192.168.0.3

ping mynet-tomcat01 容器的IP
[root@cb1922b95b93 /]# ping 192.168.0.3
PING 192.168.0.3 (192.168.0.3) 56(84) bytes of data.
64 bytes from 192.168.0.3: icmp_seq=1 ttl=64 time=0.186 ms
^C
--- 192.168.0.3 ping statistics ---
7 packets transmitted, 7 received, 0% packet loss, time 6000ms
rtt min/avg/max/mdev = 0.090/0.127/0.186/0.029 ms
直接ping 容器名 mynet-centos01 mynet-tomcat01
[root@cb1922b95b93 /]# ping mynet-centos01
PING mynet-centos01 (192.168.0.2) 56(84) bytes of data.
64 bytes from mynet-centos01.mynet (192.168.0.2): icmp_seq=1 ttl=64 time=0.105 ms
^C
--- mynet-centos01 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2001ms
rtt min/avg/max/mdev = 0.105/0.116/0.130/0.013 ms

[root@cb1922b95b93 /]# ping mynet-tomcat01
PING mynet-tomcat01 (192.168.0.3) 56(84) bytes of data.
64 bytes from mynet-tomcat01.mynet (192.168.0.3): icmp_seq=1 ttl=64 time=0.085 ms
^C
--- mynet-tomcat01 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 0.085/0.093/0.102/0.012 ms
[root@cb1922b95b93 /]# 

结论
其它网络下的容器可以通过加入docker网络，来访问该docker网络下的容器，并且既可以通过容器ip也可以通过容器名连接，非常方便。docker0十分强大