docker容器网络配置

Linux内核实现名称空间的创建

ip netns命令

可以借助ip netns命令来完成对 Network Namespace 的各种操作。ip netns命令来自于iproute安装包，一般系统会默认安装，如果没有的话，请自行安装。

注意：ip netns命令修改网络配置时需要 sudo 权限。

可以通过ip netns命令完成对Network Namespace 的相关操作，可以通过ip netns help查看命令帮助信息：

[root@wang ~]# ip netns help
Usage: ip netns list
       ip netns add NAME
       ip netns set NAME NETNSID
       ip [-all] netns delete [NAME]
       ip netns identify [PID]
       ip netns pids NAME
       ip [-all] netns exec [NAME] cmd ...
       ip netns monitor
       ip netns list-id

默认情况下，Linux系统中是没有任何 Network Namespace的，所以ip netns list命令不会返回任何信息。

创建Network Namespace

通过命令创建一个名为wm1的命名空间：

[root@wang ~]# ip netns list
[root@wang ~]# ip netns add wm1
[root@wang ~]# ip netns list
wm1

新创建的 Network Namespace 会出现在/var/run/netns/目录下。如果相同名字的 namespace 已经存在,则会报错

对于每个 Network Namespace 来说，它会有自己独立的网卡、路由表、ARP 表、iptables 等和网络相关的资源。

操作Network Namespace

ip命令提供了ip netns exec子命令可以在对应的 Network Namespace 中执行命令。

查看新创建 Network Namespace 的网卡信息

[root@wang ~]# ip netns exec wm1 ip addr
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

　　启动网卡

[root@wang ~]# ip netns exec wm1 ip link set lo up
[root@wang ~]# ip netns exec wm1 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
[root@wang ~]# ip netns exec wm1 ping 127.0.0.1
PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data.
64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.055 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.056 ms

转移设备

我们可以在不同的 Network Namespace 之间转移设备（如veth）。由于一个设备只能属于一个 Network Namespace ，所以转移后在这个 Network Namespace 内就看不到这个设备了。

其中，veth设备属于可转移设备，而很多其它设备（如lo、vxlan、ppp、bridge等）是不可以转移的。

veth pair

veth pair 全称是 Virtual Ethernet Pair，是一个成对的端口，所有从这对端口一端进入的数据包都将从另一端出来，反之也是一样。
引入veth pair是为了在不同的 Network Namespace 直接进行通信，利用它可以直接将两个 Network Namespace 连接起来。

创建veth pair,时系统中新增了一对veth pair，将veth0和veth1两个虚拟网卡连接了起来，此时这对 veth pair 处于”未启用“状态。

[root@wang ~]# ip link add type veth
[root@wang ~]# ip link show 
10: veth0@veth1: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether ce:a0:4c:d5:e3:d1 brd ff:ff:ff:ff:ff:ff
11: veth1@veth0: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether 66:23:70:62:8b:62 brd ff:ff:ff:ff:ff:ff

实现Network Namespace间通信

下面我们利用veth pair实现两个不同的 Network Namespace 之间的通信。刚才我们已经创建了一个名为ns0的 Network Namespace，下面再创建一个信息Network Namespace，命名为wm2

[root@wang ~]# ip netns add wm2
[root@wang ~]# ip netns list
wm2
wm1

将veth0加入到wm1，将veth1加入到wm2,

[root@wang ~]# ip link set veth0 netns wm1
[root@wang ~]# ip link set veth1 netns wm2
[root@wang ~]# ip netns exec wm1 ip a
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
10: veth0@if11: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether ce:a0:4c:d5:e3:d1 brd ff:ff:ff:ff:ff:ff link-netns wm2
[root@wang ~]# ip netns exec wm2 ip link show
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
11: veth1@if10: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether 66:23:70:62:8b:62 brd ff:ff:ff:ff:ff:ff link-netns wm1

给veth0 pair配置上ip地址，并启用，以及查看当前状态

[root@wang ~]# ip netns exec wm1 ip addr add 192.168.170.11/24 dev veth0
[root@wang ~]# ip netns exec wm1 ip link set veth0 up
[root@wang ~]# ip netns exec wm1 ip a
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
10: veth0@if11: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state LOWERLAYERDOWN group default qlen 1000
    link/ether ce:a0:4c:d5:e3:d1 brd ff:ff:ff:ff:ff:ff link-netns wm2
    inet 192.168.170.11/24 scope global veth0
       valid_lft forever preferred_lft forever

　给veth1配置IP，并启用，以及查看当前状态

[root@wang ~]# ip netns exec wm2 ip addr add 192.168.170.12/24 dev veth1
[root@wang ~]# ip netns exec wm2 ip link set veth1 up
[root@wang ~]# ip netns exec wm2 ip a
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
11: veth1@if10: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 66:23:70:62:8b:62 brd ff:ff:ff:ff:ff:ff link-netns wm1
    inet 192.168.170.12/24 scope global veth1
       valid_lft forever preferred_lft forever
    inet6 fe80::6423:70ff:fe62:8b62/64 scope link 
       valid_lft forever preferred_lft forever

veth设备重命名

更改网卡名之前需要先停止网卡，再进行改名

[root@wang ~]# ip netns exec wm1 ip link set veth0 down
[root@wang ~]# ip netns exec wm1 ip link set dev veth0 name eth0
[root@wang ~]# ip netns exec wm1 ip link set eth0 up
[root@wang ~]# ip netns exec wm1 ip a
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
10: eth0@if11: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether ce:a0:4c:d5:e3:d1 brd ff:ff:ff:ff:ff:ff link-netns wm2
    inet 192.168.170.11/24 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::cca0:4cff:fed5:e3d1/64 scope link 
       valid_lft forever preferred_lft forever

四种网络模式配置

bridge模式配置

该模式为默认模式，跟不加--network选项效果是一致的

[root@wang ~]# docker run -it --name wangming --rm busybox
/ # 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
12: eth0@if13: <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

none模式配置，该模式没有网卡配置

[root@wang ~]# docker run -it --name wm --network none --rm busybox
/ # 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

container模式配置

启动第一个容器

[root@wang ~]# docker run -it --name wm --rm busybox
/ # 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
14: eth0@if15: <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

　　启动第二个容器

[root@wang ~]# docker run -it --name wm1 --network container:wm --rm busybox
/ # 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
14: eth0@if15: <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

此时我们在wm容器上创建一个目录

/ # mkdir tmp/data
/ # ls
bin   etc   proc  sys   usr
dev   home  root  tmp   var
/ # ls /tmp/
data

到wm1容器上检查/tmp目录会发现并没有这个目录，因为文件系统是处于隔离状态，仅仅是共享了网络而已。

在b2容器上部署一个站点

/ # echo 'hello world' > /tmp/index.html
/ # httpd -h /tmp/
/ # netstat -antl
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       
tcp        0      0 :::80                   :::*                    LISTEN

在wm容器上用本地地址去访问此站点　　

/ # wget -O - -q 127.0.0.1:80
hello world

由此可见，container模式下的容器间关系就相当于一台主机上的两个不同进程　　

host模式配置

启动容器时直接指明模式为host

本机网络配置

[root@wang ~]# ip a
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: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:36:f6:1e brd ff:ff:ff:ff:ff:ff
    inet 192.168.170.20/24 brd 192.168.170.255 scope global noprefixroute ens160
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe36:f61e/64 scope link 
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:09:c6:82:10 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::42:9ff:fec6:8210/64 scope link 
       valid_lft forever preferred_lft forever

　　host网络配置

[root@wang ~]# docker run -it --name wm --rm --network host busybox
/ # 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
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel qlen 1000
    link/ether 00:0c:29:36:f6:1e brd ff:ff:ff:ff:ff:ff
    inet 192.168.170.20/24 brd 192.168.170.255 scope global ens160
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe36:f61e/64 scope link 
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue 
    link/ether 02:42:09:c6:82:10 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::42:9ff:fec6:8210/64 scope link 
       valid_lft forever preferred_lft forever

　　此时如果我们在这个容器中启动一个http站点，我们就可以直接用宿主机的IP直接在浏览器中访问这个容器中的站点了。

/ # echo 'hello world' > /tmp/index.html
/ # httpd -h tmp/
/ # netstat -antl
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      
tcp        0      0 192.168.170.20:22       192.168.170.1:51589     ESTABLISHED 
tcp        0      0 192.168.170.20:22       192.168.170.1:55888     ESTABLISHED 
tcp        0      0 :::22                   :::*                    LISTEN      
tcp        0      0 :::3306                 :::*                    LISTEN      
tcp        0      0 :::80                   :::*                    LISTEN

容器的常用操作

查看容器的主机名

[root@wang ~]# docker run -it --rm busybox
/ # hostname
05725a300086

在容器启动时注入主机名

[root@wang ~]# docker run -it --rm --hostname wangming busybox
/ # hostname 
wangming

　主机映射关系以及DNS会自动配置

/ # cat /etc/hosts 
127.0.0.1	localhost
::1	localhost ip6-localhost ip6-loopback
fe00::0	ip6-localnet
ff00::0	ip6-mcastprefix
ff02::1	ip6-allnodes
ff02::2	ip6-allrouters
172.17.0.2	wangming
/ # cat /etc/resolv.conf 
# Generated by NetworkManager
nameserver 192.168.170.2

　　更改dns

[root@wang ~]# docker run -it --rm --hostname wangming --dns 8.8.8.8 busybox
/ # cat /etc/resolv.conf 
nameserver 8.8.8.8

　如遇无法ping同，请重启主机亦可成功

[root@wang ~]# docker run -it --rm busybox
/ # ping www.baidu.com
PING www.baidu.com (182.61.200.6): 56 data bytes
64 bytes from 182.61.200.6: seq=0 ttl=127 time=28.577 ms
64 bytes from 182.61.200.6: seq=1 ttl=127 time=25.445 ms

手动往/etc/hosts文件中注入主机名到IP地址的映射

[root@wang ~]# docker run -it --name wm --hostname wangming --add-host wm:6.6.6.6 --rm busybox
/ # cat /etc/hosts
127.0.0.1	localhost
::1	localhost ip6-localhost ip6-loopback
fe00::0	ip6-localnet
ff00::0	ip6-mcastprefix
ff02::1	ip6-allnodes
ff02::2	ip6-allrouters
6.6.6.6	wm
172.17.0.2	wangming

开放容器端口

执行docker run的时候有个-p选项，可以将容器中的应用端口映射到宿主机中，从而实现让外部主机可以通过访问宿主机的某端口来访问容器内应用的目的。

-p选项能够使用多次，其所能够暴露的端口必须是容器确实在监听的端口。

-p选项的使用格式：

-p <containerPort>
- 将指定的容器端口映射至主机所有地址的一个动态端口
-p <hostPort>:<containerPort>
- 将容器端口<containerPort>映射至指定的主机端口<hostPort>
-p <ip>::<containerPort>
- 将指定的容器端口<containerPort>映射至主机指定<ip>的动态端口
-p <ip>:<hostPort>:<containerPort>
- 将指定的容器端口<containerPort>映射至主机指定<ip>的端口<hostPort>

动态端口指的是随机端口，具体的映射结果可使用docker port命令查看。（常用的为端口号由自己设置的方法）

-p <containerPort> 用法，将容器的随机号端口映射为真机的80端口

[root@wang ~]# docker run -itd --rm -p 80  httpd
cbc6fe8cebc2b4ad8fceca335e7bec2b048ec21abad4725401285b9f6d3d18f9
[root@wang ~]# docker ps
CONTAINER ID   IMAGE     COMMAND              CREATED         STATUS         PORTS                   NAMES
cbc6fe8cebc2   httpd     "httpd-foreground"   8 seconds ago   Up 6 seconds   0.0.0.0:49154->80/tcp   cranky_elion
[root@wang ~]# ss -antl
State Recv-Q Send-Q  Local Address:Port  Peer Address:Port 
LISTEN0      128           0.0.0.0:22         0.0.0.0:*    
LISTEN0      128           0.0.0.0:49154      0.0.0.0:*    
LISTEN0      128              [::]:22            [::]:*    
LISTEN0      80                  *:3306             *:*

　　-p <hostPort>:<containerPort>用法将容器的99号端口映射为真机的80端口

[root@wang ~]# docker run -itd --rm -p 99:80 httpd
[root@wang ~]# docker ps 
CONTAINER ID   IMAGE     COMMAND              CREATED          STATUS          PORTS                NAMES
bec31062cde6   httpd     "httpd-foreground"   59 seconds ago   Up 58 seconds   0.0.0.0:99->80/tcp   flamboyant_heyrovsky
[root@wang ~]# curl 172.17.0.2
<html><body><h1>It works!</h1></body></html>
[root@wang ~]# ss -antl
State Recv-Q Send-Q  Local Address:Port  Peer Address:Port 
LISTEN0      128           0.0.0.0:22         0.0.0.0:*    
LISTEN0      128           0.0.0.0:99         0.0.0.0:*    
LISTEN0      128              [::]:22            [::]:*    
LISTEN0      80                  *:3306             *:*

　　-p <ip>::<containerPort>用法，IP必须真实存在，将容器的随机号端口映射为真机的80端口

[root@wang ~]# docker run -itd --rm -p 192.168.170.20::80 httpd
666eb91715c9d6e3224c089195a75ff6318ea147ce72dafa9be8d8d11534105a
[root@wang ~]# docker ps
CONTAINER ID   IMAGE     COMMAND              CREATED          STATUS          PORTS                          NAMES
666eb91715c9   httpd     "httpd-foreground"   30 seconds ago   Up 29 seconds   192.168.170.20:49153->80/tcp   friendly_ptolemy
bec31062cde6   httpd     "httpd-foreground"   3 minutes ago    Up 3 minutes    0.0.0.0:99->80/tcp             flamboya
[root@wang ~]# curl 172.17.0.3
<html><body><h1>It works!</h1></body></html>
[root@wang ~]# ss -antl
State Recv-Q Send-Q   Local Address:Port  Peer Address:Port
LISTEN0      128            0.0.0.0:22         0.0.0.0:*   
LISTEN0      128     192.168.170.20:49153      0.0.0.0:*   
LISTEN0      128            0.0.0.0:99         0.0.0.0:*   
LISTEN0      128               [::]:22            [::]:*   
LISTEN0      80                   *:3306             *:*

　　-p <ip>:<hostPort>:<containerPort>用法，IP必须真实存在，将容器的66号端口映射为真机的80端口

[root@wang ~]# docker run -itd --rm -p 192.168.170.20:66:80 httpd
acd07582ef7da8fff7d564d9505f14ed6304a5980fc760fbd20e61d15f755712[root@wang ~]# docker ps
CONTAINER ID   IMAGE     COMMAND              CREATED          STATUS          PORTS                          NAMES
acd07582ef7d   httpd     "httpd-foreground"   52 seconds ago   Up 51 seconds   192.168.170.20:66->80/tcp      unruffled_elion
666eb91715c9   httpd     "httpd-foreground"   7 minutes ago    Up 7 minutes    192.168.170.20:49153->80/tcp   friendly_ptolemy
bec31062cde6   httpd     "httpd-foreground"   10 minutes ago   Up 10 minutes   0.0.0.0:99->80/tcp             flamboyant_heyrovsky
[root@wang ~]# curl 172.17.0.4
<html><body><h1>It works!</h1></body></html>
[root@wang ~]# ss -antl
State Recv-Q Send-Q   Local Address:Port  Peer Address:Port
LISTEN0      128            0.0.0.0:22         0.0.0.0:*   
LISTEN0      128     192.168.170.20:49153      0.0.0.0:*   
LISTEN0      128     192.168.170.20:66         0.0.0.0:*   
LISTEN0      128            0.0.0.0:99         0.0.0.0:*   
LISTEN0      128               [::]:22            [::]:*   
LISTEN0      80                   *:3306             *:*

　　查看容器端口的映射关系，接上容器的id

[root@wang ~]# docker port acd07582ef7d 
80/tcp -> 192.168.170.20:66

　iptables防火墙规则将随容器的创建自动生成，随容器的删除自动删除规则。

[root@wang ~]# iptables -t nat -nvL
Chain PREROUTING (policy ACCEPT 20 packets, 1929 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    2   104 DOCKER     all  --  *      *       0.0.0.0/0            0.0.0.0/0            ADDRTYPE match dst-type LOCAL

Chain INPUT (policy ACCEPT 2 packets, 104 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain POSTROUTING (policy ACCEPT 45 packets, 2650 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    3   202 MASQUERADE  all  --  *      !docker0  172.17.0.0/16        0.0.0.0/0           
    0     0 MASQUERADE  tcp  --  *      *       172.17.0.2           172.17.0.2           tcp dpt:80
    0     0 MASQUERADE  tcp  --  *      *       172.17.0.3           172.17.0.3           tcp dpt:80
    0     0 MASQUERADE  tcp  --  *      *       172.17.0.4           172.17.0.4           tcp dpt:80

Chain OUTPUT (policy ACCEPT 45 packets, 2650 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    1    60 DOCKER     all  --  *      *       0.0.0.0/0           !127.0.0.0/8          ADDRTYPE match dst-type LOCAL

Chain DOCKER (2 references)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 RETURN     all  --  docker0 *       0.0.0.0/0            0.0.0.0/0           
    0     0 DNAT       tcp  --  !docker0 *       0.0.0.0/0            0.0.0.0/0            tcp dpt:99 to:172.17.0.2:80
    0     0 DNAT       tcp  --  !docker0 *       0.0.0.0/0            192.168.170.20       tcp dpt:49153 to:172.17.0.3:80
    0     0 DNAT       tcp  --  !docker0 *       0.0.0.0/0            192.168.170.20       tcp dpt:66 to:172.17.0.4:80

　停止所有容器后，规则删除

[root@wang ~]# iptables -t nat -nvL
Chain PREROUTING (policy ACCEPT 20 packets, 1929 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    2   104 DOCKER     all  --  *      *       0.0.0.0/0            0.0.0.0/0            ADDRTYPE match dst-type LOCAL

Chain INPUT (policy ACCEPT 2 packets, 104 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain POSTROUTING (policy ACCEPT 45 packets, 2650 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    3   202 MASQUERADE  all  --  *      !docker0  172.17.0.0/16        0.0.0.0/0           

Chain OUTPUT (policy ACCEPT 45 packets, 2650 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    1    60 DOCKER     all  --  *      *       0.0.0.0/0           !127.0.0.0/8          ADDRTYPE match dst-type LOCAL

Chain DOCKER (2 references)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 RETURN     all  --  docker0 *       0.0.0.0/0            0.0.0.0/0

自定义docker0桥的网络属性信息

官方文档相关配置

自定义docker0桥的网络属性信息需要修改/etc/docker/daemon.json配置文件

{
    "bip": "192.168.1.5/24",  //网桥IP
    "fixed-cidr": "192.168.1.5/25",
    "fixed-cidr-v6": "2001:db8::/64",
    "mtu": 1500,
    "default-gateway": "10.20.1.1",  //默认网关地址
    "default-gateway-v6": "2001:db8:abcd::89",
    "dns": ["10.20.1.2","10.20.1.3"]  //默认dns
}

　修改默认网桥,网桥不能改为本机的网段

[root@wang ~]# vim  /etc/docker/daemon.json 
[root@wang ~]# cat /etc/docker/daemon.json 
{
	"bip": "192.168.150.1/24",
	"dns": ["192.168.170.2"],
       	"registry-mirrors": ["https://8v1ihtvi.mirror.aliyuncs.com"]
}
[root@wang ~]# docker run -it --rm  busybox
/ # 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
38: eth0@if39: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:c0:a8:96:02 brd ff:ff:ff:ff:ff:ff
    inet 192.168.150.2/24 brd 192.168.150.255 scope global eth0
       valid_lft forever preferred_lft forever
/ # cat /etc/resolv.conf 
nameserver 192.168.170.2

核心选项为bip，即bridge ip之意，用于指定docker0桥自身的IP地址；其它选项可通过此地址计算得出。

docker创建自定义桥

创建一个额外的自定义桥，区别于docker0

[root@wang ~]# docker network ls
NETWORK ID     NAME      DRIVER    SCOPE
b5e299f5862c   bridge    bridge    local
753839871b8d   host      host      local
74e51934b019   none      null      local
[root@wang ~]# docker network create -d bridge --subnet "192.168.2.0/24" --gateway "192.168.2.1" br0
e589851c10d517a2293f27fb5d59c99f75a3df285350b5c774794cdcf04910ca
[root@wang ~]# docker network ls
NETWORK ID     NAME      DRIVER    SCOPE
e589851c10d5   br0       bridge    local
b5e299f5862c   bridge    bridge    local
753839871b8d   host      host      local
74e51934b019   none      null      local

　　使用新创建的自定义桥来创建容器

[root@wang ~]# docker run -it --rm --name wm1 --network br0 busybox
/ # 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
61: eth0@if62: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:c0:a8:02:02 brd ff:ff:ff:ff:ff:ff
    inet 192.168.2.2/24 brd 192.168.2.255 scope global eth0
       valid_lft forever preferred_lft forever

　　再创建一个使用默认的bridge桥，查看两者区别

[root@wang ~]# docker run -it --rm --name wm2 busybox
/ # 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
63: eth0@if64: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:c0:a8:96:02 brd ff:ff:ff:ff:ff:ff
    inet 192.168.150.2/24 brd 192.168.150.255 scope global eth0
       valid_lft forever preferred_lft forever

　　试想一下，此时的wm1与wm2能否互相通信？如果不能该如何实现通信？

通信方法：

[root@wang ~]# docker network ls
NETWORK ID     NAME      DRIVER    SCOPE
e589851c10d5   br0       bridge    local
b5e299f5862c   bridge    bridge    local
753839871b8d   host      host      local
74e51934b019   none      null      local
wm1未添加网卡前的状态
[root@wang ~]# docker run -it --rm --name wm1 --network br0 busybox
/ # 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
61: eth0@if62: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:c0:a8:02:02 brd ff:ff:ff:ff:ff:ff
    inet 192.168.2.2/24 brd 192.168.2.255 scope global eth0
       valid_lft forever preferred_lft forever
wm2未添加网卡前的状态
root@wang ~]# docker run -it --rm --name wm2 busybox
/ # 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
63: eth0@if64: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:c0:a8:96:02 brd ff:ff:ff:ff:ff:ff
    inet 192.168.150.2/24 brd 192.168.150.255 scope global eth0
       valid_lft forever preferred_lft forever

　利用docker 　network connect 添加容器网卡

[root@wang cdrom]# docker network connect br0 wm2
[root@wang cdrom]# docker network connect bridge wm1
wm1容器添加后的状态，并成功ping通
/ # 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
61: eth0@if62: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:c0:a8:02:02 brd ff:ff:ff:ff:ff:ff
    inet 192.168.2.2/24 brd 192.168.2.255 scope global eth0
       valid_lft forever preferred_lft forever
69: eth1@if70: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:c0:a8:96:03 brd ff:ff:ff:ff:ff:ff
    inet 192.168.150.3/24 brd 192.168.150.255 scope global eth1
       valid_lft forever preferred_lft forever
/ # ping 192.168.150.2
PING 192.168.150.2 (192.168.150.2): 56 data bytes
64 bytes from 192.168.150.2: seq=0 ttl=64 time=0.739 ms
64 bytes from 192.168.150.2: seq=1 ttl=64 time=0.183 ms
^C
--- 192.168.150.2 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.183/0.461/0.739 ms
wm2容器添加网卡后状态，成功ping通
/ # 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
63: eth0@if64: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:c0:a8:96:02 brd ff:ff:ff:ff:ff:ff
    inet 192.168.150.2/24 brd 192.168.150.255 scope global eth0
       valid_lft forever preferred_lft forever
67: eth1@if68: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:c0:a8:02:03 brd ff:ff:ff:ff:ff:ff
    inet 192.168.2.3/24 brd 192.168.2.255 scope global eth1
       valid_lft forever preferred_lft forever
/ # ping 192.168.2.2
PING 192.168.2.2 (192.168.2.2): 56 data bytes
64 bytes from 192.168.2.2: seq=0 ttl=64 time=0.615 ms
64 bytes from 192.168.2.2: seq=1 ttl=64 time=0.183 ms
^C
--- 192.168.2.2 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.183/0.399/0.615 ms

posted @ 2021-03-02 17:04 海绵堡堡阅读(544) 评论(0) 收藏举报

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