1. 网络模式
检查没有任何启动的端口
nginx容器与busybox 容器使用一个网络命名空间
发现busybox容器中多了个80端口
- 1.5. 自定义网络
启动容器并指定使用自定义网络
docker run -itd —name bs3 —net 自定义网络的名字 busybox
检查发现两个容器使用同一个自定义网络可以互ping 可以ping—>ip 主机名容器名
# ping容器名
ping容器主机名
2. 容器网络访问原理
3. 桥接宿主机网络与配置固定ip地址

1. 网络模式

1.1. bridge

应用较多
–net=bridge默认网络，Docker启动后创建一个docker0网桥，默认创建的容器也是添加到这个网桥中。
桥接利用linux的网桥实现的，启动docker后创建一个docker0的网桥

1.2. host

应用较多
–net=host容器不会获得一个独立的网络命令空间network namespace，而是与宿主机共用一个。这就意味着容器不会有自己的网卡信息，而是使用宿主机的。容器除了网络，其他都是隔离的。
一个网络命令空间相当于一个网络世界
在这个容器中起的任何服务都是使用的宿主机的网络命名空间，例如在容器中启用了nginx服务占用80端口，其实就是占用的宿主机的80端口

[root@centos7 ~]# docker pull busybox
Using default tag: latest
latest: Pulling from library/busybox
7c9d20b9b6cd: Pull complete 
Digest: sha256:dd97a3fe6d721c5cf03abac0f50e2848dc583f7c4e41bf39102ceb42edfd1808
Status: Downloaded newer image for busybox:latest
docker.io/library/busybox:latest
[root@centos7 ~]# ifconfig 
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:c6ff:fe70:5949  prefixlen 64  scopeid 0x20<link>
        ether 02:42:c6:70:59:49  txqueuelen 0  (Ethernet)
        RX packets 6  bytes 1146 (1.1 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 16  bytes 1234 (1.2 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.0.0.201  netmask 255.255.255.0  broadcast 10.0.0.255
        inet6 fe80::20c:29ff:fe71:86bb  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:71:86:bb  txqueuelen 1000  (Ethernet)
        RX packets 2035  bytes 957273 (934.8 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 1341  bytes 163892 (160.0 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
eth1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.16.1.201  netmask 255.255.255.0  broadcast 172.16.1.255
        inet6 fe80::20c:29ff:fe71:86c5  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:71:86:c5  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 14  bytes 1008 (1008.0 B)
        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 2  bytes 100 (100.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2  bytes 100 (100.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
veth845c544: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet6 fe80::e038:f0ff:fe55:5d8f  prefixlen 64  scopeid 0x20<link>
        ether e2:38:f0:55:5d:8f  txqueuelen 0  (Ethernet)
        RX packets 6  bytes 1230 (1.2 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 24  bytes 1882 (1.8 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

[root@centos7 ~]# docker run -it --net=host busybox
/ # ifconfig 
docker0   Link encap:Ethernet  HWaddr 02:42:C6:70:59:49  
          inet addr:172.17.0.1  Bcast:172.17.255.255  Mask:255.255.0.0
          inet6 addr: fe80::42:c6ff:fe70:5949/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:6 errors:0 dropped:0 overruns:0 frame:0
          TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:1146 (1.1 KiB)  TX bytes:1234 (1.2 KiB)

eth0      Link encap:Ethernet  HWaddr 00:0C:29:71:86:BB  
          inet addr:10.0.0.201  Bcast:10.0.0.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe71:86bb/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2022 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1330 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:956171 (933.7 KiB)  TX bytes:159110 (155.3 KiB)

eth1      Link encap:Ethernet  HWaddr 00:0C:29:71:86:C5  
          inet addr:172.16.1.201  Bcast:172.16.1.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe71:86c5/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:14 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:1008 (1008.0 B)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:2 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:100 (100.0 B)  TX bytes:100 (100.0 B)

veth845c544 Link encap:Ethernet  HWaddr E2:38:F0:55:5D:8F  
          inet6 addr: fe80::e038:f0ff:fe55:5d8f/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:6 errors:0 dropped:0 overruns:0 frame:0
          TX packets:24 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:1230 (1.2 KiB)  TX bytes:1882 (1.8 KiB)

/ #

1.3. none

场景应用非常少
–net=none获取独立的network namespace，但不为容器进行任何网络配置，需要我们手动配置。
通常是用于有别的网络驱动程序能配置ip，或者想自己手动配置ip，因为就是一个网络命名空间，直接通过ip ns 这个命令去对这个网络命名空间去设置ip

1.4. container

–net=container:Name/ID与指定的容器使用同一个network namespace，具有同样的网络配置信息，两个容器除了网络，其他都还是隔离的。
与指定的容器使用一个网络命名空间，两个容器具有相同的网络配置信息，两个容器使用相同的网络协议栈，其他都还是隔离的
使用方法：—net container:容器ID/容器名(需要使用同一个网络命名空间的容器)
docker run -d —name nginx_bs —net container:容器ID/容器名(需要使用同一个网络命名空间的容器) nginx
# 启动busybox容器

[root@centos7 ~]# docker run -itd --name bs busybox
92b6b87ba790a7012765c111b1aa742c518a4d0b5368f08f0647cfd5d5ada2b9

检查没有任何启动的端口

[root@centos7 ~]# docker exec -it bs netstat -antp
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name

nginx容器与busybox 容器使用一个网络命名空间

[root@centos7 ~]# docker run -d --name nginx_bs --net container:bs nginx
510e729ad8489e1197588c3483d4fe3836d731292cc8c76745b77b5b3896c2ce

发现busybox容器中多了个80端口

[root@centos7 ~]# docker exec -it bs netstat -antp
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      -

1.5. 自定义网络

与默认的bridge原理一样，但自定义网络具备内部DNS发现，可以通过容器名或者主机名容器之间网络通信。
像这种通信在早期使用一个叫link的，而最近一个版本给弃用了，现在最佳方式是使用自定义网络，保证这一套服务的通信
# 创建自定义网络
创建自定义网络：docker network create 自定义网络的名字

[root@centos7 ~]# docker network create bs-test
ca75dfca5a1f4697daa5d1e4b516bce119d3497a64b93888342bdf8b0169fd85

启动容器并指定使用自定义网络
docker run -itd —name bs3 —net 自定义网络的名字 busybox

[root@centos7 ~]# docker run -itd --name bs3 --net bs-test busybox
7e91970e4fe438eddf97f1d47beff89126d6cd75a744a389f340cf0d4ec197e6
[root@centos7 ~]# docker run -itd --name bs4 --net bs-test busybox
87351b2856c8c59b8f6a97d78749ed3c41db7f4c7fc03541cfa12b94d3bf8da2

检查发现两个容器使用同一个自定义网络可以互ping 可以ping—>ip 主机名容器名
# ping容器名

[root@centos7 ~]# docker exec -it bs3 ping bs4
PING bs4 (172.18.0.3): 56 data bytes
64 bytes from 172.18.0.3: seq=0 ttl=64 time=0.127 ms
64 bytes from 172.18.0.3: seq=1 ttl=64 time=0.118 ms
^C
--- bs4 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.118/0.122/0.127 ms
[root@centos7 ~]# docker exec -it bs4 ping bs3
PING bs3 (172.18.0.2): 56 data bytes
64 bytes from 172.18.0.2: seq=0 ttl=64 time=0.059 ms
64 bytes from 172.18.0.2: seq=1 ttl=64 time=0.236 ms
^C
--- bs3 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.059/0.147/0.236 ms

ping容器主机名

[root@centos7 ~]# docker exec -it bs3 hostname
7e91970e4fe4
[root@centos7 ~]# docker exec -it bs4 hostname
87351b2856c8
[root@centos7 ~]# docker exec -it bs3 ping 87351b2856c8
PING 87351b2856c8 (172.18.0.3): 56 data bytes
64 bytes from 172.18.0.3: seq=0 ttl=64 time=0.078 ms
64 bytes from 172.18.0.3: seq=1 ttl=64 time=0.220 ms
^C
--- 87351b2856c8 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.078/0.149/0.220 ms
[root@centos7 ~]# docker exec -it bs4 ping 7e91970e4fe4
PING 7e91970e4fe4 (172.18.0.2): 56 data bytes
64 bytes from 172.18.0.2: seq=0 ttl=64 time=0.067 ms
^C
--- 7e91970e4fe4 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 0.067/0.067/0.067 ms

容器网络