文章目录
前言
一：Dcker网络资源详解
简单云平台生态环境图
普通单节点 桥接图
1.1：网络资源详解：Docker0网卡与四种网络模式
我们安装完Docker时，会发现系统已经自动创建了一个docker0网卡和其他Docker网络模式
[root@docker ~]# 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:29:68:b8:a6 brd ff:ff:ff:ff:ff:ff
inet 192.168.233.133/24 brd 192.168.233.255 scope global noprefixroute ens33
valid_lft forever preferred_lft forever
inet6 fe80::35a9:b12:5e2b:c44d/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 02:42:47:ba:2a:13 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
[root@docker ~]# docker network ls '//自动创建了三个网络'
NETWORK ID NAME DRIVER SCOPE
17c7a951c27d bridge bridge local
7bc6ae3204ea host host local
953022b62b1c none null local
二 . Docker0网卡的解释
Docker安装完成之后，Docker0网卡被当做容器的网关，容器启动时会从此网段分配一个IP地址给容器，称为container-ip，容器之间也是通过Docker0进行通信
由于Docker0网卡是虚拟出来的，所以外部网络无法直接进行通讯，只能通过端口映射来进行访问容器
1. host模式
容器与宿主机共享network namespace
容器将使用宿主机的IP地址与端口，但是容器的其他方面，如文件系统等仍旧是与宿主机隔离
优点是网络性能好，无需nat转换
缺点是网络的隔离性不好，用过的端口就不能再用了
2. container模式
container模式是和一个已经存在的容器共享一个network namespace，新创建的容器不会创建自己的网卡与自己的ip，如此，这 两个容器可以通过lo网卡设备进行通信
但是和host模式一样，文件系统，进程列表等还是隔离的
3. none模式
none模式关闭了容器的网络功能，
容器会有自己的network namespace，但是容器不会有其他的网络配置，如网卡，ip，路由等信息，我们需要自己手动添加
优点是网络封闭性好，容器安全性高
4 . bridge模式
bridge模式会为每一个容器分配、设置一个IP地址等，并将容器通过veth对连接到一个Docker0虚拟网桥，通过docker0网桥以及iptables nat表配置与宿主机通信
bridge模式是Docker的默认模式，一般Docker都会使用172.17.0.0/16这个网段
二 ：网络模式的使用方法
指定模式和指定ip
桥接模式是默认的，不需要指定，如果要指定模式，需要添加–net=“none”,–net=“host”, –
net="container:name or id" 例如：
[root@docker ~]# docker run -it centos:7 /bin/bash '//这个默认就是桥接模式'
桥接模式无法直接指定ip，如果想指定ip需要先自行创建网络，创建的网络和Docker0网络统同级
[root@docker ~]# docker network create --subnet=172.18.0.0/24 mynetwork
[root@docker ~]# docker run -itd --name test004 --net mynetwork --ip 172.18.0.10 centos:7 /bin/bash
[root@docker ~]# docker ps -a
三 . 小案例
1. 创建自定义网桥 mybework,并指定网段
[root@docker2 ~]# docker network create --subnet=172.18.0.0/24 mynetwork
19d86a0d935fee82cc692babe5760b7303fe1be93f1f8e4ba93c80d1d2b17c17
[root@docker2 ~]# ifconfig
br-19d86a0d935f: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 172.18.0.1 netmask 255.255.255.0 broadcast 172.18.0.255
ether 02:42:58:33:a7:e1 txqueuelen 0 (Ethernet)
RX packets 41 bytes 3153 (3.0 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 49 bytes 3211 (3.1 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
docker0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255
inet6 fe80::42:76ff:fe5d:22a1 prefixlen 64 scopeid 0x20<link>
ether 02:42:76:5d:22:a1 txqueuelen 0 (Ethernet)
RX packets 20315 bytes 827845 (808.4 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 22061 bytes 134128614 (127.9 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.100.11 netmask 255.255.255.0 broadcast 192.168.100.255
inet6 fe80::20c:29ff:fe0e:5518 prefixlen 64 scopeid 0x20<link>
ether 00:0c:29:0e:55:18 txqueuelen 1000 (Ethernet)
RX packets 123326 bytes 149402434 (142.4 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 49778 bytes 6449791 (6.1 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 16 bytes 800 (800.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 16 bytes 800 (800.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth8383311: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::6cdb:eeff:fec2:ce8b prefixlen 64 scopeid 0x20<link>
ether 6e:db:ee:c2:ce:8b txqueuelen 0 (Ethernet)
RX packets 41 bytes 3153 (3.0 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 49 bytes 3211 (3.1 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
virbr0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 192.168.122.1 netmask 255.255.255.0 broadcast 192.168.122.255
ether 52:54:00:48:6e:c2 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
2. 创建容器，指定桥接到网卡mynetwork，并指定其IP 为 172.18.0.10
[root@docker2 ~]# docker run -itd --name test2 --net mynetwork --ip 172.18.0.10 centos:7 /bin/bash
3e45de1e549ad41ab97e24cdb01df50531d550f771c094a560db262506b7e758
[root@docker2 ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
3e45de1e549a centos:7 "/bin/bash" 13 seconds ago Up 11 seconds test2
83a4476a2a6e centos:7 "/bin/bash" 37 seconds ago Created
3. 进入容器查看IP 确认
[root@docker2 ~]# docker exec -it 3e45de1e549a bash
[root@3e45de1e549a /]# ifconfig
Yum install net-tools -y
[root@3e45de1e549a /]# ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 172.18.0.10 netmask 255.255.255.0 broadcast 172.18.0.255
ether 02:42:ac:12:00:0a txqueuelen 0 (Ethernet)
RX packets 2234 bytes 11881774 (11.3 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 2211 bytes 122963 (120.0 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
loop txqueuelen 1000 (Local Loopback)
RX packets 82 bytes 7643 (7.4 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 82 bytes 7643 (7.4 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
[root@3e45de1e549a /]#
4 . 查看宿主机 网卡列表
[root@docker2 mysql]# docker network ls
NETWORK ID NAME DRIVER SCOPE
0d8a08e72533 bridge bridge local
41aec0a12cdb host host local
19d86a0d935f mynetwork bridge local
68aa8c25f2bc none null local
5. 通过ID 号对应，可以确认IP网段范围
[root@docker2 mysql]# ifconfig
br-19d86a0d935f: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 172.18.0.1 netmask 255.255.255.0 broadcast 172.18.0.255
inet6 fe80::42:58ff:fe33:a7e1 prefixlen 64 scopeid 0x20<link>
ether 02:42:58:33:a7:e1 txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 21 bytes 2440 (2.3 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0