docker網絡配置過程詳解介紹

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Linux內核實現名稱空間的創建

ip netns命令

可以借助ip netns命令來完成對 Network Namespace 的各種操作。ip netns命令來自於iproute安裝包，一般系統會默認安裝，如果沒有的話，請自行安裝。

註意：ip netns命令修改網絡配置時需要 sudo 權限。

可以通過ip netns命令完成對Network Namespace 的相關操作，可以通過ip netns help查看命令幫助信息：

[root@master ~]# 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 [target-nsid POSITIVE-INT] [nsid POSITIVE-INT]
NETNSID := auto | POSITIVE-INT
[root@master ~]# ip netns list
[root@master ~]# ip netns add ns0
[root@master ~]# ip netns list
ns0
[root@master ~]# ls /var/run/netns
ns0
[root@master ~]# ip netns add ns0
Cannot create namespace file "/var/run/netns/ns0": File exists
[root@master ~]# touch /var/run/netns/ns1
[root@master ~]# ip netns list
Error: Peer netns reference is invalid.
Error: Peer netns reference is invalid.
ns1
ns0
[root@master ~]# ip netns del ns1
[root@master ~]# ip netns list
ns0

操作Network Namespace

ip命令提供瞭ip netns exec子命令可以在對應的 Network Namespace 中執行命令。

查看新創建 Network Namespace 的網卡信息

[root@master ~]# ip netns exec ns0 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
可以看到，新創建的Network Namespace中會默認創建一個lo回環網卡，此時網卡處於關閉狀態。此時，嘗試去 ping 該lo回環網卡，會提示Network is unreachable
[root@master ~]# ip netns exec ns0 ping 127.0.0.1
connect: 網絡不可達
通過下面的命令啟用lo回環網卡
[root@master ~]# ip netns exec ns0 ip link set lo up
[root@master ~]# ip netns exec ns0 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=0.024 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.019 ms

轉移設備

我們可以在不同的 Network Namespace 之間轉移設備（如veth）。由於一個設備隻能屬於一個 Network Namespace ，所以轉移後在這個 Network Namespace 內就看不到這個設備瞭。

其中，veth設備屬於可轉移設備，而很多其它設備（如lo、vxlan、ppp、bridge等）是不可以轉移的。

veth pair

veth pair 全稱是 Virtual Ethernet Pair，是一個成對的端口，所有從這對端口一 端進入的數據包都將從另一端出來，反之也是一樣。

引入veth pair是為瞭在不同的 Network Namespace 直接進行通信，利用它可以直接將兩個 Network Namespace 連接起來。

在這裡插入圖片描述

創建veth pair

[root@master ~]# 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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:d7:ce:07 brd ff:ff:ff:ff:ff:ff
    inet 192.168.197.131/24 brd 192.168.197.255 scope global dynamic noprefixroute ens33
       valid_lft 1522sec preferred_lft 1522sec
    inet6 fe80::1f2f:a9f9:78a7:7cc/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:f1:42:78 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:f1:42:78 brd ff:ff:ff:ff:ff:ff
5: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:b8:38:aa:7d 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:b8ff:fe38:aa7d/64 scope link 
       valid_lft forever preferred_lft forever
7: veth2672252@if6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
    link/ether ca:56:6c:07:de:af brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::c856:6cff:fe07:deaf/64 scope link 
       valid_lft forever preferred_lft forever
[root@master ~]# ip link add type veth
[root@master ~]# 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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:d7:ce:07 brd ff:ff:ff:ff:ff:ff
    inet 192.168.197.131/24 brd 192.168.197.255 scope global dynamic noprefixroute ens33
       valid_lft 1499sec preferred_lft 1499sec
    inet6 fe80::1f2f:a9f9:78a7:7cc/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:f1:42:78 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:f1:42:78 brd ff:ff:ff:ff:ff:ff
5: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:b8:38:aa:7d 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:b8ff:fe38:aa7d/64 scope link 
       valid_lft forever preferred_lft forever
7: veth2672252@if6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
    link/ether ca:56:6c:07:de:af brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::c856:6cff:fe07:deaf/64 scope link 
       valid_lft forever preferred_lft forever
10: veth0@veth1: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether a2:0f:68:39:2c:fd brd ff:ff:ff:ff:ff:ff
11: veth1@veth0: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether e6:e9:55:96:60:35 brd ff:ff:ff:ff:ff:ff

可以看到，此時系統中新增瞭一對veth pair，將veth0和veth1兩個虛擬網卡連接瞭起來，此時這對 veth pair 處於”未啟用“狀態。

實現Network Namespace間通信

[root@master ~]#  ip netns list
ns0
[root@master ~]# ip netns add ns1
[root@master ~]# ip link set veth0 netns ns0
[root@master ~]# ip link set veth1 netns ns1
[root@master ~]# ip netns exec ns0 ip link set veth0 up
[root@master ~]# ip netns exec ns0 ip addr add 192.168.2.1/24 dev veth0
[root@master ~]# ip netns exec ns1 ip link set veth1 up
[root@master ~]# ip netns exec ns1  ip addr add 192.168.2.2/24 dev veth1
[root@master ~]# ip netns exec ns0 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,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether a2:0f:68:39:2c:fd brd ff:ff:ff:ff:ff:ff link-netns ns1
    inet 192.168.2.1/24 scope global veth0
       valid_lft forever preferred_lft forever
    inet6 fe80::a00f:68ff:fe39:2cfd/64 scope link 
       valid_lft forever preferred_lft forever
[root@master ~]# ip netns exec ns1 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 e6:e9:55:96:60:35 brd ff:ff:ff:ff:ff:ff link-netns ns0
    inet 192.168.2.2/24 scope global veth1
       valid_lft forever preferred_lft forever
    inet6 fe80::e4e9:55ff:fe96:6035/64 scope link 
       valid_lft forever preferred_lft forever
[root@master ~]# ip netns exec ns1 ping 192.168.2.1
PING 192.168.2.1 (192.168.2.1) 56(84) bytes of data.
64 bytes from 192.168.2.1: icmp_seq=1 ttl=64 time=0.037 ms
64 bytes from 192.168.2.1: icmp_seq=2 ttl=64 time=0.028 ms

可以看到，veth pair成功實現瞭兩個不同Network Namespace之間的網絡交互。

veth設備重命名

[root@master ~]# ip netns exec ns0 ip link set veth0 down
[root@master ~]# ip netns exec ns0 ip link set veth0 down
[root@master ~]# ip netns exec ns0 ip link set veth0 down
[root@master ~]# ip netns exec ns0 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 noqueue state DOWN group default qlen 1000
    link/ether a2:0f:68:39:2c:fd brd ff:ff:ff:ff:ff:ff link-netns ns1
    inet 192.168.2.1/24 scope global veth0
       valid_lft forever preferred_lft forever
[root@master ~]# ip netns exec ns1 ip link set veth1 down 
[root@master ~]# ip netns exec ns1 ip link  set dev veth1 name eth0
[root@master ~]# ip netns exec ns1 ip link set eth0
[root@master ~]# ip netns exec ns1 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: eth0@if10: <BROADCAST,MULTICAST> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether e6:e9:55:96:60:35 brd ff:ff:ff:ff:ff:ff link-netns ns0
    inet 192.168.2.2/24 scope global eth0
       valid_lft forever preferred_lft forever

四種網絡模式配置

bridge模式

[root@master ~]# docker pull busybox
Using default tag: latest
latest: Pulling from library/busybox
3aab638df1a9: Pull complete 
Digest: sha256:52817dece4cfe26f581c834d27a8e1bcc82194f914afe6d50afad5a101234ef1
Status: Downloaded newer image for busybox:latest
docker.io/library/busybox:latest
[root@master ~]# docker run -it --name b1 --rm busybox # --rm 刪除或停止容器後自動銷毀容器
/ # 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:11:00:03 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
/ # exit
[root@master ~]# docker run -it --name b1 --network bridge --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:11:00:03 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
/ # exit

none模式

[root@master ~]# docker run -it --name b2 --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
/ # exit
使用none模式，Docker容器擁有自己的Network Namespace，但是，並不為Docker容器進行任何網絡配置。也就是說，這個Docker容器沒有網卡、IP、路由等信息。需要我們自己為Docker容器添加網卡、配置IP等。

container模式

[root@master ~]# docker run -it --name b3 --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
16: eth0@if17: <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
新開一個終端
[root@master ~]# docker run -it --name b4 --rm --network container:b3 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
16: eth0@if17: <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
 在b3上創建一個文件
/ # ls
bin   dev   etc   home  proc  root  sys   tmp   usr   var
/ # mkdir yy
在b4上查看
/ # ls
bin   dev   etc   home  proc  root  sys   tmp   usr   var
在b3上創建網站
/ # echo "aaa." > bbb/index.html
/ # httpd -h bbb/
/ # netstat -antl
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       
tcp        0      0 :::80                   :::*                    LISTE

# 在b4上訪問
/ # wget -qO - 172.17.0.2
aaa
/ #
# 由此可見，container模式下的容器間關系就相當於一臺主機上的兩個不同進程

這個模式指定新創建的容器和已經存在的一個容器共享一個 Network Namespace，而不是和宿主機共享。新創建的容器不會創建自己的網卡，配置自己的 IP，而是和一個指定的容器共享 IP、端口范圍等。同樣，兩個容器除瞭網絡方面，其他的如文件系統、進程列表等還是隔離的。兩個容器的進程可以通過 lo 網卡設備通信。

host模式
啟動容器時直接指明模式為host

[root@master ~]# docker run -it --name b5 --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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel qlen 1000
    link/ether 00:0c:29:d7:ce:07 brd ff:ff:ff:ff:ff:ff
    inet 192.168.197.131/24 brd 192.168.197.255 scope global dynamic noprefixroute ens33
       valid_lft 1741sec preferred_lft 1741sec
    inet6 fe80::1f2f:a9f9:78a7:7cc/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue qlen 1000
    link/ether 52:54:00:f1:42:78 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master virbr0 qlen 1000
    link/ether 52:54:00:f1:42:78 brd ff:ff:ff:ff:ff:ff
5: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue 
    link/ether 02:42:b8:38:aa:7d 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:b8ff:fe38:aa7d/64 scope link 
       valid_lft forever preferred_lft forever
7: veth2672252@if6: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue master docker0 
    link/ether ca:56:6c:07:de:af brd ff:ff:ff:ff:ff:ff
    inet6 fe80::c856:6cff:fe07:deaf/64 scope link 
       valid_lft forever preferred_lft forever
/ # mkdir www
/ # echo "ccc" > www/index.html
/ # httpd -h www/
/ # 
[root@master ~]# 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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:d7:ce:07 brd ff:ff:ff:ff:ff:ff
    inet 192.168.197.131/24 brd 192.168.197.255 scope global dynamic noprefixroute ens33
       valid_lft 1730sec preferred_lft 1730sec
    inet6 fe80::1f2f:a9f9:78a7:7cc/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:f1:42:78 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:f1:42:78 brd ff:ff:ff:ff:ff:ff
5: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:b8:38:aa:7d 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:b8ff:fe38:aa7d/64 scope link 
       valid_lft forever preferred_lft forever
7: veth2672252@if6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
    link/ether ca:56:6c:07:de:af brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::c856:6cff:fe07:deaf/64 scope link 
       valid_lft forever preferred_lft forever
[root@master ~]# curl 192.168.197.131
ccc

容器的常用操作

[root@master ~]# docker run -it --name b6 --rm busybox
/ # hostname
ef156ee78b70
/ # exit
[root@master ~]# docker run -it --name b6 --hostname yanghaixx busybox
/ # hostname 
yanghaixx
/ # 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
172.17.0.3      yanghaixx
/ # cat /etc/resolv.conf 
# Generated by NetworkManager
search localdomain
nameserver 192.168.197.2
/ # ping baidu.com
PING baidu.com (220.181.38.148): 56 data bytes
64 bytes from 220.181.38.148: seq=0 ttl=127 time=25.224 ms
64 bytes from 220.181.38.148: seq=1 ttl=127 time=24.795 ms
[root@master ~]# docker run -it --rm  --name b7 --dns 8.8.8.8 --hostname yanghaixx busybox
/ # cat /etc/resolv.conf 
search localdomain
nameserver 8.8.8.8

/ # exit .
[root@master ~]# docker run -it --name b7 --rm --hostname yanghaixx --add-host baidu.com:0.0.0.0  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
0.0.0.0 baidu.com
172.17.0.3      yanghaixx

端口映射
執行docker run的時候有個-p選項，可以將容器中的應用端口映射到宿主機中，從而實現讓外部主機可以通過訪問宿主機的某端口來訪問容器內應用的目的。

-p選項能夠使用多次，其所能夠暴露的端口必須是容器確實在監聽的端口。

-p選項的使用格式：

-p
將指定的容器端口映射至主機所有地址的一個動態端口
動態端口指的是隨機端口，具體的映射結果可使用docker port命令查看。

[root@master ~]# docker run -d --name web1 --rm -p 80 yanghaixx/nginx:v2
62029a5977a06e07ab5b40c78ce60e9cc519364512bc2e6d5785afd7dc1e090f
[root@master ~]#  docker port web1
80/tcp -> 0.0.0.0:49153
80/tcp -> :::49153
[root@master ~]# curl 192.168.197.131:49153
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

將容器端口映射到宿主機的指定端口

[root@master ~]# docker run -itd --name web2 --rm -p 2525:80 yanghaixx/nginx:v2
62a93a8ef40eec981b2d1682da92523027999991b0294782be38d4565b210ff8
[root@master ~]# docker port web2
80/tcp -> 0.0.0.0:2525
80/tcp -> :::2525
[root@master ~]# curl 192.168.197.131:2525
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

自定義docker0橋的網絡屬性信息

自定義docker0橋的網絡屬性信息需要修改/etc/docker/daemon.json配置文件

[root@master ~]# vim /etc/docker/daemon.json
[root@master ~]# cat /etc/docker/daemon.json
{
        "registry-mirrors": ["https://q9u587gb.mirror.aliyuncs.com"]
        "bip": "192.168.2.1/24"
}
See "systemctl status docker.service" and "journalctl -xe" for details.
[root@master ~]# 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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:d7:ce:07 brd ff:ff:ff:ff:ff:ff
    inet 192.168.197.131/24 brd 192.168.197.255 scope global dynamic noprefixroute ens33
       valid_lft 1690sec preferred_lft 1690sec
    inet6 fe80::1f2f:a9f9:78a7:7cc/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:f1:42:78 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:f1:42:78 brd ff:ff:ff:ff:ff:ff
5: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:97:2a:95:42 brd ff:ff:ff:ff:ff:ff
    inet 192.168.2.1/24 brd 192.168.2.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:97ff:fe2a:9542/64 scope link 
       valid_lft forever preferred_lft forever

docker創建自定義橋

[root@master ~]# vim /etc/docker/daemon.json
[root@master ~]# cat /etc/docker/daemon.json
{
        "registry-mirrors": ["https://q9u587gb.mirror.aliyuncs.com"]
        "bip": "192.168.2.1/24"
}
See "systemctl status docker.service" and "journalctl -xe" for details.
[root@master ~]# 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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:d7:ce:07 brd ff:ff:ff:ff:ff:ff
    inet 192.168.197.131/24 brd 192.168.197.255 scope global dynamic noprefixroute ens33
       valid_lft 1690sec preferred_lft 1690sec
    inet6 fe80::1f2f:a9f9:78a7:7cc/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:f1:42:78 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:f1:42:78 brd ff:ff:ff:ff:ff:ff
5: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:97:2a:95:42 brd ff:ff:ff:ff:ff:ff
    inet 192.168.2.1/24 brd 192.168.2.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:97ff:fe2a:9542/64 scope link 
       valid_lft forever preferred_lft forever

使用新創建的自定義橋來創建容器：

[root@master ~]# docker run -itd --name web --network br0 --rm yanghaixx/nginx:v2
aec728f703567b36016cf09cde1ffd1036673d7c2d961cae0b81cd09721d5cb9
[root@master ~]# docker exec -it web /bin/bash
[root@aec728f70356 /]# 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
31: eth0@if32: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:ac:11:01:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.17.1.2/24 brd 172.17.1.255 scope global eth0
       valid_lft forever preferred_lft forever

再創建一個容器，使用默認的bridge橋：

[root@master ~]# docker run -itd --name web02 --rm luojiatian1904/nginx:v2
4ee412be6d20b96a18f0b6fc0062beefc2192d906b212134b362ec41be5144ff
[root@master ~]# docker exec -it web02 /bin/bash
[root@4ee412be6d20 /]# 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
33: eth0@if34: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:c0:a8:02:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 192.168.2.2/24 brd 192.168.2.255 scope global eth0
       valid_lft forever preferred_lft forever
[root@4ee412be6d20 /]#

試想一下，此時的b2與b1能否互相通信？如果不能該如何實現通信

# 運行兩個容器在不同網段
[root@master ~]# docker run -itd --name web --network br0 --rm yanghaixx/nginx:v2
aec728f703567b36016cf09cde1ffd1036673d7c2d961cae0b81cd09721d5cb9
[root@master ~]# docker exec -it web /bin/bash
[root@aec728f70356 /]# 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
31: eth0@if32: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:ac:11:01:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.17.1.2/24 brd 172.17.1.255 scope global eth0
       valid_lft forever preferred_lft forever

[root@master ~]# docker run -itd --name web02 --rm yanghaixx/nginx:v2
4ee412be6d20b96a18f0b6fc0062beefc2192d906b212134b362ec41be5144ff
[root@master ~]# docker exec -it web02 /bin/bash
[root@4ee412be6d20 /]# 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
33: eth0@if34: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:c0:a8:02:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 192.168.2.2/24 brd 192.168.2.255 scope global eth0
       valid_lft forever preferred_lft forever


[root@master ~]# docker ps -a
CONTAINER ID   IMAGE                     COMMAND                  CREATED         STATUS         PORTS     NAMES
4ee412be6d20   luojiatian1904/nginx:v2   "/usr/local/nginx/sb…"   2 minutes ago   Up 2 minutes             web02
aec728f70356   luojiatian1904/nginx:v2   "/usr/local/nginx/sb…"   2 minutes ago   Up 2 minutes             web

將br0網絡 (C1) 連接到c2(一個容器運行兩個橋)

[root@master ~]# docker network connect  br0 aec728f70356(web容器ID)
[root@4ee412be6d20 /]# 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
33: eth0@if34: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:c0:a8:02:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 192.168.2.2/24 brd 192.168.2.255 scope global eth0
       valid_lft forever preferred_lft forever
35: eth1@if36: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:ac:11:01:03 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.17.1.3/24 brd 172.17.1.255 scope global eth1
       valid_lft forever preferred_lft forever

[root@4ee412be6d20 /]# ping 172.17.1.2
PING 172.17.1.2 (172.17.1.2) 56(84) bytes of data.
64 bytes from 172.17.1.2: icmp_seq=1 ttl=64 time=0.095 ms

到此這篇關於docker網絡配置過程詳解介紹的文章就介紹到這瞭,更多相關docker網絡配置內容請搜索WalkonNet以前的文章或繼續瀏覽下面的相關文章希望大傢以後多多支持WalkonNet！

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