docker容器网络配置

时间：2021-03-03 08:33:28 阅读：25 评论：0 收藏：0 [点我收藏+]

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@cst ~]# ip netns help
Usage:	ip netns list
	ip netns add NAME
	ip netns attach NAME PID
	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

创建Network Namespace

通过命令创建一个名为a1的命名空间：

[root@cst ~]# ip netns list
[root@cst ~]# ip netns add a1
[root@cst ~]# ip netns list
a1

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，命令会报Cannot create namespace file "/var/run/netns/ns0": File exists的错误。

[root@cst ~]# ls /var/run/netns/
a1

[root@cst ~]# ip netns add a1
Cannot create namespace file "/var/run/netns/a1": File exists

注：直接在netns文件夹内创建文件，无法使用netns list命令识别

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@cst ~]# ip netns exec a1 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

//通过下面的命令启用lo回环网卡，不启用ping不通
[root@cst ~]# ip netns exec a1 ip link set lo up
[root@cst ~]# ip netns exec a1 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

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。

技术分享图片

创建veth pair

[root@cst ~]# ip link add type veth
[root@cst ~]# ip link show

4: veth0@veth1: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 86:5b:f5:b5:68:31 brd ff:ff:ff:ff:ff:ff
5: veth1@veth0: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 9a:b6:48:f1:bf:2a brd ff:ff:ff:ff:ff:ff

可以看到，此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。

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a0

[root@cst ~]# ip netns add a0
[root@cst ~]# ip netns list
a0
a1

将veth0加入到a0，将veth1加入到a1

[root@cst ~]# ip link set veth0 netns a0
[root@cst ~]# ip link set veth1 netns a1

分别为这对veth pair配置上ip地址，并启用它们

[root@cst ~]# ip netns exec a0 ip link set lo up
[root@cst ~]# ip netns exec a0 ip link set veth0 up
[root@cst ~]# ip netns exec a0 ip addr add 1.1.1.1/24 dev veth0
[root@cst ~]# ip netns exec a1 ip link set veth1 up
[root@cst ~]# ip netns exec a1 ip addr add 1.1.1.2/24 dev veth

查看这对veth pair的状态

[root@cst ~]# ip netns exec a0 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
4: veth0@if5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 86:5b:f5:b5:68:31 brd ff:ff:ff:ff:ff:ff link-netns a1
    inet 1.1.1.1/24 scope global veth0
       valid_lft forever preferred_lft forever
    inet6 fe80::845b:f5ff:feb5:6831/64 scope link 
       valid_lft forever preferred_lft forever


[root@cst ~]# ip netns exec a1 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
5: veth1@if4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 9a:b6:48:f1:bf:2a brd ff:ff:ff:ff:ff:ff link-netns a0
    inet 1.1.1.2/24 scope global veth1
       valid_lft forever preferred_lft forever
    inet6 fe80::98b6:48ff:fef1:bf2a/64 scope link 
       valid_lft forever preferred_lft forever

我们已经成功启用了这个veth pair，并为每个veth设备分配了对应的ip地址。尝试在a1中访问a0中的ip地址：

[root@cst ~]# ip netns exec a1 ping 1.1.1.2
PING 1.1.1.2 (1.1.1.2) 56(84) bytes of data.
64 bytes from 1.1.1.2: icmp_seq=1 ttl=64 time=0.019 ms
64 bytes from 1.1.1.2: icmp_seq=2 ttl=64 time=0.029 ms
64 bytes from 1.1.1.2: icmp_seq=3 ttl=64 time=0.037 ms

可以看到，veth pair成功实现了两个不同Network Namespace之间的网络交互。

veth设备重命名

重命名需要先停用veth设备

[root@cst ~]# ip netns exec a0 ip link set veth0 down
[root@cst ~]# ip netns exec a0 ip link set dev veth0 name ve0
[root@cst ~]# ip netns exec a0 ip link set ve0 up
[root@cst ~]# ip netns exec a0 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
4: ve0@if5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 86:5b:f5:b5:68:31 brd ff:ff:ff:ff:ff:ff link-netns a1
    inet 1.1.1.1/24 scope global ve0
       valid_lft forever preferred_lft forever
    inet6 fe80::845b:f5ff:feb5:6831/64 scope link 
       valid_lft forever preferred_lft forever

四种网络模式配置

bridge模式配置

容器在创建时默认为bridge模式，即不需要添加--network选项

[root@cst ~]# docker images
REPOSITORY   TAG       IMAGE ID       CREATED       SIZE
busybox      latest    b97242f89c8a   6 weeks ago   1.23MB
httpd        latest    683a7aad17d3   7 weeks ago   138MB

[root@cst ~]# 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
4: eth0@if5: <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
/ # exit

[root@cst ~]# docker run -it --rm --network bridge 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
6: eth0@if7: <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

可以看出两种操作方式的结果相同

none模式配置

[root@cst ~]# docker run -it --rm --network none 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

//手动配置和none模式自动配置效果相同
[root@cst ~]# ip netns add b1
[root@cst ~]# ip netns exec b1 ip link set lo up
[root@cst ~]# ip netns exec b1 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

container模式配置

//启动第一个容器
[root@cst ~]# docker run -it --rm --name b1 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
8: eth0@if9: <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@cst ~]# docker run -it --rm --name b2 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
10: eth0@if11: <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
/ # exit

b1容器的ip地址为172.17.0.2，b2容器的ip地址为172.17.0.3，由此可见没有共享网络，此时如果我们将b2容器的启动方式改变一下，就可以使b2容器的ip与b1容器ip一致，也即共享ip，但不共享文件系统。

[root@cst ~]# docker run -it --rm --name b2 --network container:b1 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
8: eth0@if9: <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

//在b1上创建index.html文件
/ # echo ‘b1‘ > /etc/index.html
/ # cat etc/index.html 
b1

//在b2上创建index.html文件
/ # echo ‘b2‘ > /etc/index.html
/ # cat /etc/index.html 
b2

//在b2容器上部署一个站点
/ # netstat -antl
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       
/ # httpd -h /etc/
/ # netstat -antl
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       
tcp        0      0 :::80                   :::*                    LISTEN   

//在b1容器上用本地地址去访问此站点
/ # wget -O - 127.0.0.1
Connecting to 127.0.0.1 (127.0.0.1:80)
writing to stdout
b2
-                    100% |***************|     3  0:00:00 ETA
written to stdout
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

[root@cst ~]# docker run -it --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: ens32: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel qlen 1000
    link/ether 00:0c:29:a5:9f:a7 brd ff:ff:ff:ff:ff:ff
    inet 192.168.142.129/24 brd 192.168.142.255 scope global dynamic ens32
       valid_lft 1378sec preferred_lft 1378sec
    inet6 fe80::3e15:c05:b9ea:ecda/64 scope link 
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue 
    link/ether 02:42:a1:f4:46:42 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:a1ff:fef4:4642/64 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 ‘welcome‘ > /etc/index.html
/ # httpd -h /etc/
/ # 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      0 192.168.142.129:22      192.168.142.1:52451     ESTABLISHED 
tcp        0      0 192.168.142.129:22      192.168.142.1:52178     ESTABLISHED 
tcp        0      0 :::80                   :::*                    LISTEN      
tcp        0      0 :::22                   :::*                    LISTEN  

[root@cst ~]# curl 192.168.142.129
welcome

此时再创建一个容器部署http站点端口会冲突。

容器的常用操作

查看容器的主机名

//主机名默认为容器的ID，且无法修改主机名
[root@cst ~]# docker run -it --rm busybox
/ # hostname 
8913ba472357

[root@cst ~]# docker ps
CONTAINER ID   IMAGE     COMMAND   CREATED          STATUS          PORTS     NAMES
8913ba472357   busybox   "sh"      23 seconds ago   Up 22 seconds             nice_haibt

/ # hostname aaa
hostname: sethostname: Operation not permitted
/ # exit

在容器启动时注入主机名

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

[root@cst ~]# docker ps
CONTAINER ID   IMAGE     COMMAND   CREATED         STATUS         PORTS     NAMES
80a65eff2970   busybox   "sh"      9 seconds ago   Up 9 seconds             mystifying_wilson

//注入主机名时会自动创建主机名到IP的映射关系
/ # 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	cst

//DNS自动配置为宿主机的DNS
/ # cat /etc/resolv.conf
# Generated by NetworkManager
search localdomain
nameserver 192.168.142.2

/ # ping cst
PING cst (172.17.0.2): 56 data bytes
64 bytes from 172.17.0.2: seq=0 ttl=64 time=0.030 ms
64 bytes from 172.17.0.2: seq=1 ttl=64 time=0.046 ms
64 bytes from 172.17.0.2: seq=2 ttl=64 time=0.048 ms

手动指定容器要使用的DNS

[root@cst ~]# docker run -it --rm --hostname cst --dns 114.114.114.114 busybox
/ # cat /etc/resolv.conf
search localdomain
nameserver 114.114.114.114
/ # cat /etc/hostname
cst
/ # ping www.baidu.com
PING www.baidu.com (14.215.177.39): 56 data bytes
64 bytes from 14.215.177.39: seq=0 ttl=127 time=23.145 ms
64 bytes from 14.215.177.39: seq=1 ttl=127 time=23.617 ms
64 bytes from 14.215.177.39: seq=2 ttl=127 time=23.187 ms
^C
--- www.baidu.com ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 23.145/23.316/23.617 ms

手动往/etc/hosts文件中注入主机名到IP地址的映射

[root@cst ~]# 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
22: eth0@if23: <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
/ # hostname 
3357d64be123

//打开第二个终端并映射172.17.0.2为cst2
[root@cst ~]# docker run -it --rm --hostname cst1 --dns 114.114.114.114 --add-host cst2:172.17.0.2 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
172.17.0.2	cst2
172.17.0.3	cst1
/ # 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
26: eth0@if27: <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 cst1
PING cst1 (172.17.0.3): 56 data bytes
64 bytes from 172.17.0.3: seq=0 ttl=64 time=0.033 ms
64 bytes from 172.17.0.3: seq=1 ttl=64 time=0.047 ms
^C
--- cst1 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.033/0.040/0.047 ms

/ # ping cst2
PING cst2 (172.17.0.2): 56 data bytes
64 bytes from 172.17.0.2: seq=0 ttl=64 time=0.105 ms
64 bytes from 172.17.0.2: seq=1 ttl=64 time=0.099 ms
^C
--- cst2 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.099/0.102/0.105 ms

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
- 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
:
- 将容器端口映射至指定的主机端口
-p
::
- 将指定的容器端口映射至主机指定的动态端口
-p
:
:
- 将指定的容器端口映射至主机指定的端口

//-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
[root@cst ~]# docker run -d -p 80 httpd
20915b4254b61947c9a1b35ac9b6c0af031d90ddc8b1de181e6233627cc1e5de
[root@cst ~]# docker ps -a
CONTAINER ID   IMAGE          COMMAND              CREATED          STATUS                      PORTS                   NAMES
20915b4254b6   httpd          "httpd-foreground"   10 seconds ago   Up 9 seconds                0.0.0.0:49153->80/tcp   affectionate_wiles
9c9915feca33   7b305e823449   "sh"                 46 hours ago     Exited (0) 46 hours ago                             amazing_wiles
e1113e6ef12c   busybox        "sh"                 47 hours ago     Exited (127) 46 hours ago                           test
[root@cst ~]#  curl 172.17.0.2
<html><body><h1>It works!</h1></body></html>
[root@cst ~]# curl 192.168.142.129:49153
<html><body><h1>It works!</h1></body></html>

//-p （hostPort）:（containerPort）

将容器端口（containerPort）映射至指定的主机端口（hostPort）
[root@cst ~]# docker run -d -p 789:80 httpd
fa28a31eeabb9f6ea937bafd62824ac6ce3b17a5ce914295f34886e06b245206
[root@cst ~]# docker ps -a
CONTAINER ID   IMAGE          COMMAND              CREATED          STATUS                      PORTS                 NAMES
fa28a31eeabb   httpd          "httpd-foreground"   21 seconds ago   Up 19 seconds               0.0.0.0:789->80/tcp   condescending_bhabha
[root@cst ~]# ss -antl
State  Recv-Q  Send-Q   Local Address:Port   Peer Address:Port 
LISTEN 0       128            0.0.0.0:789         0.0.0.0:*    
LISTEN 0       128            0.0.0.0:22          0.0.0.0:*    
LISTEN 0       128               [::]:22             [::]:*  

[root@cst ~]# curl 172.17.0.3
<html><body><h1>It works!</h1></body></html>
[root@cst ~]# curl 192.168.142.129:789
<html><body><h1>It works!</h1></body></html>

//-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
[root@cst ~]# docker run -d -p 192.168.142.129::80 httpd
fb8824f1930806685ba2c3c50f8cafbaa8c5b44c89cf998b46d6c9034619f8de
[root@cst ~]# docker ps -a
CONTAINER ID   IMAGE          COMMAND              CREATED          STATUS                      PORTS                           NAMES
fb8824f19308   httpd          "httpd-foreground"   6 seconds ago    Up 5 seconds                192.168.142.129:49153->80/tcp   cool_goldberg
[root@cst ~]# ss -antl
State  Recv-Q Send-Q   Local Address:Port    Peer Address:Port 
LISTEN 0      128    192.168.142.129:49153        0.0.0.0:*    
LISTEN 0      128            0.0.0.0:789          0.0.0.0:*    
LISTEN 0      128            0.0.0.0:22           0.0.0.0:*    
LISTEN 0      128               [::]:22              [::]:* 

[root@cst ~]# curl 172.17.0.4
<html><body><h1>It works!</h1></body></html>
[root@cst ~]# curl 192.168.142.129:49153
<html><body><h1>It works!</h1></body></html>

//-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）

[root@cst ~]# docker run -d -p 192.168.142.129:80:80 httpd
74d965cbf519fa038a6ea6ba0516d0f85d130a1dd476adcda842f96bb1c34bc8
[root@cst ~]# docker ps -a
CONTAINER ID   IMAGE          COMMAND              CREATED          STATUS                      PORTS                           NAMES
74d965cbf519   httpd          "httpd-foreground"   19 seconds ago   Up 18 seconds               192.168.142.129:80->80/tcp      magical_yalow
[root@cst ~]# ss -antl
State  Recv-Q Send-Q   Local Address:Port    Peer Address:Port 
LISTEN 0      128    192.168.142.129:49153        0.0.0.0:*    
LISTEN 0      128    192.168.142.129:80           0.0.0.0:*    
LISTEN 0      128            0.0.0.0:789          0.0.0.0:*    
LISTEN 0      128            0.0.0.0:22           0.0.0.0:*    
LISTEN 0      128               [::]:22              [::]:*  

[root@cst ~]# curl 172.17.0.5
<html><body><h1>It works!</h1></body></html>
[root@cst ~]# curl 192.168.142.129:80
<html><body><h1>It works!</h1></body></html>

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。

[root@cst ~]# docker port 74d965cbf519
80/tcp -> 192.168.142.129:80

查看iptables防火墙规则详细信息

[root@cst ~]# iptables -t nat -nvL
Chain PREROUTING (policy ACCEPT 3 packets, 609 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    1    52 DOCKER     all  --  *      *       0.0.0.0/0            0.0.0.0/0            ADDRTYPE match dst-type LOCAL

Chain INPUT (policy ACCEPT 1 packets, 52 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain POSTROUTING (policy ACCEPT 66 packets, 4917 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 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 65 packets, 4857 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           
    1    60 DNAT       tcp  --  !docker0 *       0.0.0.0/0            0.0.0.0/0            tcp dpt:789 to:172.17.0.2:80
    0     0 DNAT       tcp  --  !docker0 *       0.0.0.0/0            192.168.142.129      tcp dpt:49153 to:172.17.0.3:80
    0     0 DNAT       tcp  --  !docker0 *       0.0.0.0/0            192.168.142.129      tcp dpt:80 to:172.17.0.4:80

自定义docker0桥的网络属性信息

详情参照官方文档相关配置

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

[root@cst ~]# vim /etc/docker/daemon.json
{
        "bip": "192.168.10.1/24"

}

[root@cst ~]# systemctl daemon-reload
[root@cst ~]# systemctl restart docker
[root@cst ~]# ip a

3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:b5:1a:f3:89 brd ff:ff:ff:ff:ff:ff
    inet 192.168.10.1/24 brd 192.168.10.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:b5ff:fe1a:f389/64 scope link 
       valid_lft forever preferred_lft forever

//网桥修改后，创建出来的容器虚拟网卡IP地址规律也会改变
[root@cst ~]# 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
10: eth0@if11: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue 
    link/ether 02:42:c0:a8:0a:02 brd ff:ff:ff:ff:ff:ff
    inet 192.168.10.2/24 brd 192.168.10.255 scope global eth0
       valid_lft forever preferred_lft forever
/ # route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.10.1    0.0.0.0         UG    0      0        0 eth0
192.168.10.0    0.0.0.0         255.255.255.0   U     0      0        0 eth0

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

docker远程连接

dockerd守护进程的C/S，其默认仅监听Unix Socket格式的地址(/var/run/docker.sock)，如果要使用TCP套接字，则需要修改/etc/docker/daemon.json配置文件，添加如下内容，然后重启docker服务：

"hosts": ["tcp://0.0.0.0:2375", "unix:///var/run/docker.sock"]

在客户端上向dockerd直接传递“-H|--host”选项指定要控制哪台主机上的docker容器

docker -H 192.168.10.145:2375 ps

docker容器网络配置

原文：https://www.cnblogs.com/sarenn/p/14472268.html

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