学习笔记——容器网络(3)

介绍Docker容器的3种原生网络驱动：none、host、bridge。学习容器
如何实现通信。（了解）

一、容器网络

image.png

注：
Bridge：网桥，相当于在宿主主机上虚拟了一个交换机
Overlay：k8s使用的这种方式
安装时默认安装了3种网络

[root@cent701 ~]# docker network ls
NETWORK ID          NAME                DRIVER              SCOPE
ca0b764ff09f        bridge              bridge              local
5b2b5dd70f33        host                host                local
b0ce5ca77c75        none                null                local
[root@cent701 ~]#

1.docker0网络（1）

• 安装docker前，仅有
  1）lo（loop back）回路网卡
  2）ens32 物理网卡
• 安装docker 后多了一堆
  1）docker0：网桥
  所有容器都连接在docker0网桥上，通过网桥进行通信转发，相当于虚拟的交换机。
  2）veth0feb053@if6、veth8445097@if8
  每多一个容器，就多一个这样的网络配置，是容器的网络接口。它连接的都是网桥，

[root@cent701 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN 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
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens32: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:26:44:67 brd ff:ff:ff:ff:ff:ff
    inet 192.168.227.3/24 brd 192.168.227.255 scope global ens32
       valid_lft forever preferred_lft forever
    inet6 fe80::8fec:8861:ac20:198a/64 scope link 
       valid_lft forever preferred_lft forever
3: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP 
    link/ether 02:42:a8:47:8d:5c brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:a8ff:fe47:8d5c/64 scope link 
       valid_lft forever preferred_lft forever
7: veth0feb053@if6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP 
    link/ether 1e:fc:1c:05:17:42 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::1cfc:1cff:fe05:1742/64 scope link 
       valid_lft forever preferred_lft forever
9: veth8445097@if8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP 
    link/ether 76:11:81:60:62:37 brd ff:ff:ff:ff:ff:ff link-netnsid 1
    inet6 fe80::7411:81ff:fe60:6237/64 scope link 
       valid_lft forever preferred_lft forever

docker0网络
 容器创建时，默认挂载在docker0上。
 docker0是一个linux bridge。
 docker0网络创建时已默认配置了Subnet（子网）。

image.png

1.docker0网络（2）

查看容器网络的详细信息

[root@cent701 ~]# docker network inspect bridge 
[
    {
        "Name": "bridge",
        "Id": "ca0b764ff09f68919b064caddd4d5c801a9eb79bc7f2907a75956f2afd1c210c",
        "Created": "2022-01-13T09:19:36.031401781+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": {
            "4ee19318178fa5d33bc6f91abcc3d34e3b580a9cc04fd3bfd6df6aba489f5f44": {
                "Name": "xenodochial_bassi",
                "EndpointID": "a29678dda2ec2e0eada0c9d98a9835e401a4661fd7c991f2033d470d376adf6c",
                "MacAddress": "02:42:ac:11:00:03",
                "IPv4Address": "172.17.0.3/16",
                "IPv6Address": ""
            },
            "aa9317ccabd6ebb8e44b7a7ea2c3c7ed43f789a0991dfc05486df04ff322c966": {
                "Name": "huawei4",
                "EndpointID": "d7625dfda058cc00a0acf04e1b86cf93e4ec9df804c966ca0659553701ff8789",
                "MacAddress": "02:42:ac:11:00:02",
                "IPv4Address": "172.17.0.2/16",
                "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@cent701 ~]#

网络连通性实验