一、搭建容器之间的网络
1. 查看目前的网络环境
[root@liuxin-test01 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:ca:41:84 brd ff:ff:ff:ff:ff:ff
inet 192.168.8.192/24 brd 192.168.8.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:feca:4184/64 scope link
valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
link/ether 00:0c:29:ca:41:8e brd ff:ff:ff:ff:ff:ff
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
link/ether 02:42:a3:f4:2f:40 brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 scope global docker0
valid_lft forever preferred_lft forever
inet6 fe80::42:a3ff:fef4:2f40/64 scope link
valid_lft forever preferred_lft forever
2.创建两个无网络的容器
--rm 参数讲解一下：
在Docker容器退出时，默认容器内部的文件系统仍然被保留，以方便调试并保留用户数据。
但是，对于foreground容器，由于其只是在开发调试过程中短期运行，其用户数据并无保留的必要，因而可以在容器启动时设置--rm选项，这样在容器退出时就能够自动清理容器内部的文件系统。
- --net=none 无网络环境
- --net=bridge 默认的参数，通过网桥（docker0）来设置容器的网络。也可以通过DOCKER_OPTS选项的-b参数来指定默认网桥
- --net=host 共享主机的网络环境，不推荐这么设置
- --net=container 两个容器共享IP地址和端口号等网络资源
下面两个容器是在两个终端中创建的
[root@liuxin-test01 ~]# docker run --rm -it --net=none --name='centos01' centos:7.4.1708 [root@f64cdc7ffff1 /]#
[root@liuxin-test01 ~]# docker run --rm -it --net=none --name='centos02' centos:7.4.1708 [root@cd4df383b68e /]#
3. 查看这两个容器的进程ID
[root@liuxin-test01 ~]# docker inspect -f '{{.State.Pid}}' f64
21682
[root@liuxin-test01 ~]# docker inspect -f '{{.State.Pid}}' cd4
21832
4. 为这两个容器创建虚拟的网络空间
[root@liuxin-test01 ~]# mkdir -p /var/run/netns [root@liuxin-test01 ~]# ln -s /proc/21682/ns/net /var/run/netns/21682 [root@liuxin-test01 ~]# ln -s /proc/21832/ns/net /var/run/netns/21832 [root@liuxin-test01 ~]#
5. 创建一对veth，两端命名为A、B
veth 是虚拟的以太设备，类似于网卡设备。这个是linux容器技术引进的，要求必须成对出现
[root@liuxin-test01 ~]# ip link add A type veth peer name B
[root@liuxin-test01 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:ca:41:84 brd ff:ff:ff:ff:ff:ff
inet 192.168.8.192/24 brd 192.168.8.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:feca:4184/64 scope link
valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
link/ether 00:0c:29:ca:41:8e brd ff:ff:ff:ff:ff:ff
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
link/ether 02:42:a3:f4:2f:40 brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 scope global docker0
valid_lft forever preferred_lft forever
inet6 fe80::42:a3ff:fef4:2f40/64 scope link
valid_lft forever preferred_lft forever
157: B@A: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN qlen 1000
link/ether de:f7:3b:24:a5:0e brd ff:ff:ff:ff:ff:ff
158: A@B: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN qlen 1000
link/ether 9a:65:96:de:04:90 brd ff:ff:ff:ff:ff:ff
6. 将两端分别放到两个容器中
我们可以看到，加入到容器之后，再次执行ip a 已经看不到这两个设备了
[root@liuxin-test01 ~]# ip link set A netns 21682
[root@liuxin-test01 ~]# ip link set B netns 21832
[root@liuxin-test01 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:ca:41:84 brd ff:ff:ff:ff:ff:ff
inet 192.168.8.192/24 brd 192.168.8.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:feca:4184/64 scope link
valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
link/ether 00:0c:29:ca:41:8e brd ff:ff:ff:ff:ff:ff
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
link/ether 02:42:a3:f4:2f:40 brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 scope global docker0
valid_lft forever preferred_lft forever
inet6 fe80::42:a3ff:fef4:2f40/64 scope link
valid_lft forever preferred_lft forever
7. 设置两个容器网络空间的ip
[root@liuxin-test01 ~]# ip netns exec 21682 ip addr add 192.168.99.1/32 dev A [root@liuxin-test01 ~]# ip netns exec 21832 ip addr add 192.168.99.2/32 dev B
8. 启动两个容器的网络
[root@liuxin-test01 ~]# ip netns exec 21682 ip link set A up [root@liuxin-test01 ~]# ip netns exec 21832 ip link set B up
9. 给这两个容器设置一下网关
[root@liuxin-test01 ~]# ip netns exec 21682 ip route add 192.168.99.2/32 dev A [root@liuxin-test01 ~]# ip netns exec 21832 ip route add 192.168.99.1/32 dev B
10. 测试
[root@f64cdc7ffff1 /]# ping 192.168.99.2 PING 192.168.99.2 (192.168.99.2) 56(84) bytes of data. 64 bytes from 192.168.99.2: icmp_seq=1 ttl=64 time=0.095 ms
[root@cd4df383b68e /]# ping 192.168.99.1 PING 192.168.99.1 (192.168.99.1) 56(84) bytes of data. 64 bytes from 192.168.99.1: icmp_seq=1 ttl=64 time=0.057 ms
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
