DOCKER学习_004:Docker网络

一简介

当Docker进程启动时，会在主机上创建一个名为docker0的虚拟网桥，此主机上启动的docker容器会连接到这个虚拟网桥上。虚拟网桥的工作方式和物理交换机类似，这样主机上的所有容器就通过交换机连接在了一个二层网络中。从docker0子网中分配一个ip给容器使用，并设置docker0的ip地址为容器的默认网关。在主机上创建一对虚拟网卡veth pair设备，docker将veth pair设备的一端放在新创建的容器中，并命名为eth0（容器的网卡），另一端放在主机中，以vethxxx这样类似的名字命名，并将这个网络设备加入到docker0网桥中。可以通过brctl show命令查看。而这种网络模式即称之为bridge网络模式。
除了bridge模式以外，docker原生网络，还支持另外两种模式： none和host

1.1 查看docker的网络

[root@docker-server1 ~]# docker network ls

NETWORK ID          NAME                DRIVER              SCOPE
01dcd6c7d8fa        bridge              bridge              local
6505e9ea7ccb        host                host                local
7ab639028591        none                null                local

删除所有容器

[root@docker-server1 data]# docker ps -qa |xargs docker rm -f

354fe8e46850
2fed9f37d75c
3b821b608a83
993ed9339059
9cd7c00cbfd7
e0ed338e565a
d5fe36b5a71a
b3dc7c8b56cd
a8ec13770dc0
e943751b7ce9
4ee7b1a64be5
a306908b2740

1.2本地的网卡信息

[root@docker-server1 data]# ip addr

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:91:dd:19 brd ff:ff:ff:ff:ff:ff
    inet 192.168.132.131/24 brd 192.168.132.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::bcf9:af19:a325:e2c7/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default    #自己生成的容器网桥
    link/ether 02:42:3e:dd:55:81 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::42:3eff:fedd:5581/64 scope link 
       valid_lft forever preferred_lft forever

1.3 创建一个容器，查看容器网卡

[root@docker-server1 ~]# docker run -it busybox /bin/sh

Unable to find image 'busybox:latest' locally
latest: Pulling from library/busybox
0f8c40e1270f: Pull complete 
Digest: sha256:1303dbf110c57f3edf68d9f5a16c082ec06c4cf7604831669faf2c712260b5a0
Status: Downloaded newer image for busybox:latest

/ # ip a

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    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
78: eth0@if79: <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     #网卡地址
       valid_lft forever preferred_lft forever

/ # ip route

default via 172.17.0.1 dev eth0 
172.17.0.0/16 dev eth0 scope link  src 172.17.0.2

1.4 宿主机变化

[root@docker-server1 ~]# ip addr

79: veth5e51ab1@if78: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
    link/ether 46:67:f9:c9:79:8b brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::4467:f9ff:fec9:798b/64 scope link 
       valid_lft forever preferred_lft forever

两块网卡使用桥接模式连接

二 Docker的bridge网络

网络结构示意图：

2.1 修改docker的默认网络

[root@docker-server1 ~]# cat /etc/docker/daemon.json

{
"log-driver": "journald",
"bip":"192.168.0.1/24"
}

[root@docker-server1 ~]# systemctl restart docker

[root@docker-server1 ~]# ip addr

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:91:dd:19 brd ff:ff:ff:ff:ff:ff
    inet 192.168.132.131/24 brd 192.168.132.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::bcf9:af19:a325:e2c7/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:3e:dd:55:81 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.1/24 brd 192.168.0.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:3eff:fedd:5581/64 scope link 
       valid_lft forever preferred_lft forever

[root@docker-server1 ~]# docker run -it busybox /bin/sh

/ # ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    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
82: eth0@if83: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:c0:a8:00:02 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.2/24 brd 192.168.0.255 scope global eth0
       valid_lft forever preferred_lft forever

再看宿主机

[root@docker-server1 ~]# ip addr

3: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:3e:dd:55:81 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.1/24 brd 192.168.0.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:3eff:fedd:5581/64 scope link 
       valid_lft forever preferred_lft forever
83: veth6000535@if82: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
    link/ether e6:4f:5f:61:f6:09 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::e44f:5fff:fe61:f609/64 scope link 
       valid_lft forever preferred_lft forever

在另一个机器上

2.2 验证bridge网络

开启两个容器，使用192.168.0.0/24网段

[root@docker-server2 ~]# docker run -it centos /bin/bash

[root@2d28d8051991 /]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    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
10: eth0@if11: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:c0:a8:00:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 192.168.0.2/24 brd 192.168.0.255 scope global eth0
       valid_lft forever preferred_lft forever

开另一个容器

[root@docker-server2 ~]# docker run -it centos /bin/bash

[root@73a145861fe5 /]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    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
12: eth0@if13: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:c0:a8:00:03 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 192.168.0.3/24 brd 192.168.0.255 scope global eth0
       valid_lft forever preferred_lft forever

同一个主机的两个容器可以互通

[root@2d28d8051991 /]# 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=0.218 ms
64 bytes from 192.168.0.3: icmp_seq=2 ttl=64 time=0.054 ms
64 bytes from 192.168.0.3: icmp_seq=3 ttl=64 time=0.064 ms
64 bytes from 192.168.0.3: icmp_seq=4 ttl=64 time=0.078 ms

从另一个主机的容器ping

/ # ping 192.168.0.3    #无法ping通
PING 192.168.0.3 (192.168.0.3): 56 data bytes

容器通向外部

[root@docker-server1 ~]# docker exec -it c39a503abfae /bin/sh

/ # ping www.baidu.com
PING www.baidu.com (103.235.46.39): 56 data bytes
64 bytes from 103.235.46.39: seq=0 ttl=127 time=1252.980 ms
64 bytes from 103.235.46.39: seq=1 ttl=127 time=249.676 ms
64 bytes from 103.235.46.39: seq=2 ttl=127 time=252.693 ms
64 bytes from 103.235.46.39: seq=3 ttl=127 time=306.417 ms
/ # cat /etc/resolv.conf 
# Generated by NetworkManager
nameserver 8.8.8.8

和外部的DNS一样

查看bridge网络信息：

# 通过如下命令会列出bridge网络的相关信息，其中"Containers"字段的表示是信息是指当前节点上有哪些容器使用了该网络

[root@docker-server1 ~]# docker network inspect bridge

[
    {
        "Name": "bridge",
        "Id": "4cac3a734539ba0178f382df11101c40477b9a6714c090a07bdb3278bd47524f",
        "Created": "2019-11-09T10:19:59.805931858-05:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "192.168.0.1/24",
                    "Gateway": "192.168.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "c39a503abfaeb613551febf4a191d73cab26f381cfba2b972e074c93fc35c0a9": {
                "Name": "busy_cannon",
                "EndpointID": "21f2ff7ef65e69117d94a3d80dddde25ee334f12482a866d85e4cf56d7287dbb",
                "MacAddress": "02:42:c0:a8:00:02",
                "IPv4Address": "192.168.0.2/24",
                "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": {}
    }
]

2.4 创建使用bridge网络容器的示例

[root@docker-server1 ~]# docker run -d --name web1 --net bridge nginx

42c2e52a339b76f44ba912888863810b4b7aaf379a8b5881ca0f4f4cee8622d0

[root@docker-server1 ~]# iptables -t nat -L

Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination         
DOCKER     all  --  anywhere             anywhere             ADDRTYPE match dst-type LOCAL

Chain INPUT (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         
DOCKER     all  --  anywhere            !loopback/8           ADDRTYPE match dst-type LOCAL

Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination         
MASQUERADE  all  --  192.168.0.0/24       anywhere            

Chain DOCKER (2 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere

2.5 基于bridge网络的容器访问外部网络

默认情况下，基于bridge网络容器即可访问外部网络，这是因为默认情况下，docker使用了iptables的snat转发来实现容器对外部的访问（需要内核开启net.ipv4.ip_forward=1）

外部网络访问基于bridge网络的容器

如果想让外界可以访问到基于bridge网络创建的容器提供的服务，则必须要告诉docker要使用的端口。

可以通过如下方法查看镜像会使用哪些端口：

[root@docker-server1 ~]# docker inspect nginx | jq .[]."ContainerConfig"."ExposedPorts"

{
  "80/tcp": {}
}

在创建容器的时候可以指定这个容器的端口与主机端口的映射关系：

-p： 可以指定主机与容器的端口关系，冒号左边是主机的端口，右边是映射到容器中的端口
-P：该参数会分配镜像中所有的会使用的端口，并映射到主机上的随机端口

这种端口映射基于iptables的dnat实现
查看容器的端口情况：
[root@docker-server1 ~]# docker port 1f980072d2cf

80/tcp -> 0.0.0.0:32768

如果创建容器时，-p参数后面只一个指定端口，意思是主机会随机一个端口，映射到容器的该指定端口：

下面是一个基于端口映射的示例：

[root@docker-server1 ~]# docker run -d --dns 8.8.8.8 -p 8080:80 -p 2022:22 --name webserver1 httpd:2.4

d386c0b3218db97fe54baf6e03b7f2545aca2108318b87b851a10b8b49b04a6e

[root@docker-server1 ~]# docker run -d --dns 8.8.8.8 -P --name webserver2 httpd:2.4

565f610a0e6a1b09799ee5f85fd7ec8490d320560d212c7b2f488529d63801a5

三 none网络

故名思议，none网络就是什么都没有的网络。使用none网络的容器除了lo，没有其他任何网卡，完全隔离。用于既不需要访问外部服务，也不允许外部服务访问自己的应用场景。

3.1 查看none网络信息

[root@docker-server1 ~]# docker network inspect none

[
    {
        "Name": "none",
        "Id": "7ab6390285910ad89e0bbfaf857504d455609bd39eb68b39b59cea1b0b2a10b0",
        "Created": "2019-11-09T02:36:44.439087426-05:00",
        "Scope": "local",
        "Driver": "null",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": []
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {},
        "Options": {},
        "Labels": {}
    }
]

3.2 创建使用none网络容器的示例

[root@docker-server1 ~]# docker run -it --net none busybox

/ # ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    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
/ # ping 127.0.0.1
PING 127.0.0.1 (127.0.0.1): 56 data bytes
64 bytes from 127.0.0.1: seq=0 ttl=64 time=0.052 ms
64 bytes from 127.0.0.1: seq=1 ttl=64 time=0.100 ms/ # ping 192.168.0.3
PING 192.168.0.3 (192.168.0.3): 56 data bytes
ping: sendto: Network is unreachable
/ # ping 192.168.0.1
PING 192.168.0.1 (192.168.0.1): 56 data bytes
ping: sendto: Network is unreachable

四 host网络

使用host网络的主机，与宿主机共享网络地址，可以获得最好的数据转发性能。缺点是，同一个宿主机上的多个容器共享同一个ip地址，如果多容器使用相同的端口，需要自行解决端口冲突问题。

同样的，可以通过如下方式

4.1 查看host网络信息

[root@docker-server1 ~]# docker network inspect host

[
    {
        "Name": "host",
        "Id": "6505e9ea7ccb39a251ec7ec80fe6198d874e24aff60bc036fde4ac9777aeca8c",
        "Created": "2019-11-09T02:36:44.449893094-05:00",
        "Scope": "local",
        "Driver": "host",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": []
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {},
        "Options": {},
        "Labels": {}
    }
]

4.2 创建一个使用host网络容器的示例

# 可以看到该容器没有自己的IP地址，因为它直接使用宿主机IP地址
[root@docker-server1 ~]# docker run -it --net host busybox

/ # ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:0c:29:91:dd:19 brd ff:ff:ff:ff:ff:ff
    inet 192.168.132.131/24 brd 192.168.132.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::bcf9:af19:a325:e2c7/64 scope link 
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue 
    link/ether 02:42:3e:dd:55:81 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.1/24 brd 192.168.0.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:3eff:fedd:5581/64 scope link 
       valid_lft forever preferred_lft forever

容器的网络和宿主机的网络一模一样

缺点是无法启动两个一样具有应用的容器，因为一个容器启动之后，占用一个端口，新的容器就无法在使用这个端口

以nginx为例

[root@docker-server1 ~]# docker run -d --net host nginx

[root@docker-server1 ~]# docker ps -a

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                      PORTS               NAMES
d5ce7b93140d        nginx               "nginx -g 'daemon of…"   8 seconds ago       Up 7 seconds                                    charming_nightingale

再启动一个

[root@docker-server1 ~]# docker run -d --net host nginx

[root@docker-server1 ~]# docker ps -a
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                      PORTS               NAMES
30255c80abb9        nginx               "nginx -g 'daemon of…"   1 second ago        Up 1 second                                     infallible_tu
[root@docker-server1 ~]# docker ps -a
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                              PORTS               NAMES
30255c80abb9        nginx               "nginx -g 'daemon of…"   3 seconds ago       Exited (1) Less than a second ago                       infallible_tu

五自定义网络

Docker除了提供三种的默认网络模式之外，也允许用户针对一些特定的应用场景去创建一些自定义的网络。这样属于这个网络的容器就可以单独隔离出来，它们之间可以相互通信，而不在这个网络的容器就不能直接访问到它们。一个容器可以属于多个网络，同一个自定义

网络下的容器可以通过各自的容器名访问到对方，因为会使用到docker内嵌的一个dns功能。

Docker提供三种自定义网络驱动

bridge
overlay
macvlan

自定义bridge网络

5.1 创建一个自定义网络

创建一个叫作my_net的自定义网络

[root@docker-server1 ~]# docker network ls

NETWORK ID          NAME                DRIVER              SCOPE
4cac3a734539        bridge              bridge              local
6505e9ea7ccb        host                host                local
7ab639028591        none                null                local

[root@docker-server1 ~]# docker network create --driver bridge my_net #--driver用于指定网络类型

b1c2d9c1e522f55187ca9662846c598c1e6973dd75bda756846db1a83a9e317d

可以通过docker network ls 查看到新创建的my_net网络相关信息，Subnet表示这个网络下的子网IP段，那么基于my_net自定义网络创建的容器IP都会以该IP段开头。

[root@docker-server1 ~]# docker network ls

NETWORK ID          NAME                DRIVER              SCOPE
4cac3a734539        bridge              bridge              local
6505e9ea7ccb        host                host                local
b1c2d9c1e522        my_net              bridge              local
7ab639028591        none                null                local

宿主机也会多一个网卡

[root@docker-server1 ~]# ip addr

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:91:dd:19 brd ff:ff:ff:ff:ff:ff
    inet 192.168.132.131/24 brd 192.168.132.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::bcf9:af19:a325:e2c7/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:3e:dd:55:81 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.1/24 brd 192.168.0.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:3eff:fedd:5581/64 scope link 
       valid_lft forever preferred_lft forever
94: br-b1c2d9c1e522: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:cd:4a:25:4f brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global br-b1c2d9c1e522
       valid_lft forever preferred_lft forever

多创建一个网卡

[root@docker-server1 ~]# docker network create --driver bridge  my_net2
ec4a8380b2d343dd468c7247c80e8c1349f6219dec6c19e3c4e71751981611b6
[root@docker-server1 ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:91:dd:19 brd ff:ff:ff:ff:ff:ff
    inet 192.168.132.131/24 brd 192.168.132.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::bcf9:af19:a325:e2c7/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:3e:dd:55:81 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.1/24 brd 192.168.0.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:3eff:fedd:5581/64 scope link 
       valid_lft forever preferred_lft forever
94: br-b1c2d9c1e522: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:cd:4a:25:4f brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global br-b1c2d9c1e522
       valid_lft forever preferred_lft forever
95: br-ec4a8380b2d3: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:c9:ba:23:ae brd ff:ff:ff:ff:ff:ff
    inet 172.18.0.1/16 brd 172.18.255.255 scope global br-ec4a8380b2d3
       valid_lft forever preferred_lft forever

5.2 基于my_net网络创建容器：

[root@docker-server1 ~]# docker run -d --net my_net httpd:2.4

[root@docker-server1 ~]# docker ps -a

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                      PORTS               NAMES
dc64cedce326        httpd:2.4           "httpd-foreground"       6 seconds ago       Up 5 seconds                80/tcp              optimistic_engelbart

[root@docker-server1 ~]# docker run -it --net my_net busybox

/ # ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    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
102: eth0@if103: <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
/ # ip route
default via 172.17.0.1 dev eth0 
172.17.0.0/16 dev eth0 scope link  src 172.17.0.3

通过指定子网和网关的方式创建自定义网络

5.3 通过指定子网和网关的方式创建my_net3网络

[root@docker-server1 ~]# docker network create --driver bridge --subnet 172.22.16.0/24 --gateway 172.22.16.1 my_net3

f42e46889a2ab8930e2dbd828206ebe3c94d68efd0f1fe5ccf042674e6a08189

[root@docker-server1 ~]# docker network ls

NETWORK ID          NAME                DRIVER              SCOPE
4cac3a734539        bridge              bridge              local
6505e9ea7ccb        host                host                local
b1c2d9c1e522        my_net              bridge              local
ec4a8380b2d3        my_net2             bridge              local
f42e46889a2a        my_net3             bridge              local
7ab639028591        none                null                local

5.4 创建一个容器使用my_net3网络

[root@docker-server1 ~]# docker run -it --net my_net3 busybox

/ # ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    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
105: eth0@if106: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:ac:16:10:02 brd ff:ff:ff:ff:ff:ff
    inet 172.22.16.2/24 brd 172.22.16.255 scope global eth0
       valid_lft forever preferred_lft forever
/ # ip route
default via 172.22.16.1 dev eth0 
172.22.16.0/24 dev eth0 scope link  src 172.22.16.2

创建一个容器的使用my_net3网络的同时指定其ip地址
[root@docker-server1 ~]# docker run -it --network=my_net3 --ip=172.22.16.8 busybox

/ # ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    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
107: eth0@if108: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:ac:16:10:08 brd ff:ff:ff:ff:ff:ff
    inet 172.22.16.8/24 brd 172.22.16.255 scope global eth0
       valid_lft forever preferred_lft forever
/ # ip route
default via 172.22.16.1 dev eth0 
172.22.16.0/24 dev eth0 scope link  src 172.22.16.8

5.5 使用自定义网络与默认网络互通

清掉所有容器

[root@docker-server1 ~]# docker ps -qa |xargs docker rm -f

假设我们在默认的bridge网络中，还有一个busybox的容器：

此时默认网络中的容器与my_net2网络中的容器是无法互相通信的。宿主机上网络结构如下：

以默认网卡创建一个容器

[root@docker-server1 ~]# docker run -it busybox /bin/sh

/ # ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    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
111: eth0@if112: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:c0:a8:00:02 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.2/24 brd 192.168.0.255 scope global eth0
       valid_lft forever preferred_lft forever

自定义网卡创建容器

[root@docker-server1 ~]# docker run -it --net my_net busybox /bin/sh

/ # ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    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
115: eth0@if116: <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@docker-server1 ~]# docker run -it --net my_net busybox /bin/sh

/ # ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    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
117: eth0@if118: <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
/ # 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=0.374 ms
64 bytes from 172.17.0.2: seq=1 ttl=64 time=0.125 ms
^C
--- 172.17.0.2 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.125/0.249/0.374 ms
/ # ping 192.168.0.2
PING 192.168.0.2 (192.168.0.2): 56 data bytes

如果想让默认bridge网络的busybox与my_net中的容器通信，可以给容器添加一块自定义网络的网卡，使用以下方式

查看容器信息

[root@docker-server1 ~]# docker ps -a　　　

CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
8423a78ce12d        busybox             "/bin/sh"           3 minutes ago       Up 3 minutes                            xenodochial_pasteur
cbc45429caa8        busybox             "/bin/sh"           4 minutes ago       Up 4 minutes                            competent_poitras
623ae56a899c        busybox             "/bin/sh"           6 minutes ago       Up 5 minutes                            exciting_visvesvaraya

相当于是给623ae56a899c容器添加my_net网卡

[root@docker-server1 ~]# docker network connect my_net 623ae56a899c

再查看容器的网卡

/ # ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    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
111: eth0@if112: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:c0:a8:00:02 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.2/24 brd 192.168.0.255 scope global eth0
       valid_lft forever preferred_lft forever
119: eth1@if120: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:ac:11:00:04 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.4/16 brd 172.17.255.255 scope global eth1
       valid_lft forever preferred_lft forever
/ # 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=0.195 ms
64 bytes from 172.17.0.2: seq=1 ttl=64 time=0.073 ms
^C
--- 172.17.0.2 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.073/0.134/0.195 ms
/ # 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=0.194 ms
64 bytes from 172.17.0.3: seq=1 ttl=64 time=0.072 ms

可是my_net依然不能和默认bridge通信

在添加

[root@docker-server1 ~]# docker network connect bridge cbc45429caa8

第二个容器都可通信

/ # ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    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
115: eth0@if116: <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
121: eth1@if122: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:c0:a8:00:03 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.3/24 brd 192.168.0.255 scope global eth1
       valid_lft forever preferred_lft forever
/ # ping 192.168.0.2
PING 192.168.0.2 (192.168.0.2): 56 data bytes
64 bytes from 192.168.0.2: seq=0 ttl=64 time=0.288 ms
64 bytes from 192.168.0.2: seq=1 ttl=64 time=0.147 ms

5.6 删掉网卡

如果要将webserver新添加的这块网卡移除，可以使用如下命令：

[root@docker-server1 ~]# docker network disconnect bridge cbc45429caa8

/ # ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
    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
115: eth0@if116: <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
/ # ping 192.168.0.2    #又不能通信了
PING 192.168.0.2 (192.168.0.2): 56 data bytes

同一台宿主机容器互联

同一台宿主机上的容器互联有两种方式，第一种是基于ip，默认情况下，同一个宿主机上的容器ip是互通的。另一种方式是使用--link实现：
docker run -d --name db1 -e "MYSQL_ROOT_PASSWORD=123456" -P mysql:5.6
docker run -d --link db1:db1 --name webserver1 httpd:2.4

博主声明：本文的内容来源主要来自誉天教育晏威老师，由本人实验完成操作验证，需要的博友请联系誉天教育（http://www.yutianedu.com/），获得官方同意或者晏老师（https://www.cnblogs.com/breezey/）本人同意即可转载，谢谢！

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原文地址：https://www.cnblogs.com/zyxnhr/p/11830919.html

DOCKER学习_004:Docker网络

一 简介

1.1 查看docker的网络

1.2本地的网卡信息

1.3 创建一个容器，查看容器网卡

1.4 宿主机变化

二 Docker的bridge网络

2.1 修改docker的默认网络

2.2 验证bridge网络

2.4 创建使用bridge网络容器的示例

2.5 基于bridge网络的容器访问外部网络

三 none网络

3.1 查看none网络信息

3.2 创建使用none网络容器的示例

四 host网络

4.1 查看host网络信息

4.2 创建一个使用host网络容器的示例

五 自定义网络

5.1 创建一个自定义网络

5.3 通过指定子网和网关的方式创建my_net3网络

5.4 创建一个容器使用my_net3网络

5.5 使用自定义网络与默认网络互通

一简介

五自定义网络