--xxong亲自验证

目前市面上主流的解决方法有flannel, weave, Pipework, Open vSwitch等。

Open vSwitch实现比较简单，成熟且功能强大，所以很适合作为解决docker底层网络互联互通的工具。
拓扑如下：
重点 我这里两个宿主机的系统分别是 ： Master ： centos7.2 node ：centos6.10
Master 10.16.170.10 docker 192.168.18.0/24
Node 172.16.17.2 docker 192.168.42.0/24
鉴于centos6系统的限制 这里选择openvswitch-2.3.0的版本 下面有关于centos6安装时遇到的各种问题
具体的实现步骤如下：

1. 安装docker, bridge-utils和openvswitch
[root@master ~]# yum install docker bridge-utils -y 
[root@master ~]# yum install wget openssl-devel -y 
[root@master ~]# yum groupinstall "Development Tools"
[root@master ~]# adduser ovswitch
[root@master ~]# su - ovswitch
[ovswitch@master ~]$ wget http://openvswitch.org/releases/openvswitch-2.3.0.tar.gz
[ovswitch@master ~]$ tar -zxvpf openvswitch-2.3.0.tar.gz
[ovswitch@master ~]$ mkdir -p ~/rpmbuild/SOURCES
[ovswitch@master ~]$ sed 's/openvswitch-kmod, //g' openvswitch-2.3.0/rhel/openvswitch.spec > openvswitch-2.3.0/rhel/openvswitch_no_kmod.spec
[ovswitch@master ~]$ cp openvswitch-2.3.0.tar.gz rpmbuild/SOURCES/

[ovswitch@master ~]$ rpmbuild -bb --without check ~/openvswitch-2.3.0/rhel/openvswitch_no_kmod.spec  
  这里如果报错 No build ID found in.... 需要在openvswitch_no_kmod.spec文件中加入 %define __debug_install_post   \
   %{_rpmconfigdir}/find-debuginfo.sh %{?_find_debuginfo_opts} "%{_builddir}/%{?buildsubdir}"\
%{nil}
[ovswitch@master ~]$ exit
[root@master ~]# yum localinstall /home/ovswitch/rpmbuild/RPMS/x86_64/openvswitch-2.3.0-1.x86_64.rpm -y      
注意：相应的位置只有这一个rpm包   切记： 如果装1.9.3的版本的话 这里是有俩个包的  但是网上文档基本都只显示一个rpm包 也就是是说在这上一步 需要rpmbuild 一个openvswitch.spec否则，进行这一步时会报错 缺依赖； 
并且，这里可能会提示你需要glibc2.14 ,表示glibc版本太低 需要升级glibc版本，我这边的话直接rpm 下载glibc来进行升级的   这里的话提供一个链接：https://www.cnblogs.com/dpf-learn/p/8763696.html

[root@master ~]# mkdir /etc/openvswitch
[root@master ~]# setenforce 0

2. docker master端配置如下
[root@master ~]# systemctl start openvswitch.service  && systemctl enable openvswitch.service
[root@master ~]# ovs-vsctl add-br br0
[root@master ~]# ip addr
1: lo:  mtu 65536 qdisc noqueue state UNKNOWN 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: eth0:  mtu 1500 qdisc fq state UP qlen 1000
    link/ether 00:0c:29:97:92:e8 brd ff:ff:ff:ff:ff:ff
    inet 10.16.170.10/24 brd 255.255.255.0 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe97:92e8/64 scope link
       valid_lft forever preferred_lft forever
3: docker0:  mtu 1500 qdisc noqueue state UP
    link/ether 02:42:45:b7:c2:fd brd ff:ff:ff:ff:ff:ff
    inet 192.168.18.1/24 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:45ff:feb7:c2fd/64 scope link
       valid_lft forever preferred_lft forever
5: vethcff8026@if4:  mtu 1500 qdisc noqueue master docker0 state UP
    link/ether 32:4a:f5:b7:33:f7 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::304a:f5ff:feb7:33f7/64 scope link
       valid_lft forever preferred_lft forever
6: ovs-system:  mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether 8a:ac:8e:a1:68:2b brd ff:ff:ff:ff:ff:ff
7: br0:  mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether 82:ae:47:8e:30:4d brd ff:ff:ff:ff:ff:ff
[root@master ~]# ovs-vsctl add-port br0 gre0 -- set interface gre0 type=gre option:remote_ip=172.16.17.2
[root@master ~]# ovs-vsctl show
4fe9a5b3-46ec-432c-a990-bb8e8fee96fe
    Bridge "br0"
        Port "gre0"
            Interface "gre0"
                type: gre
                options: {remote_ip="172.16.17.2"}
        Port "br0"
            Interface "br0"
                type: internal
    ovs_version: "2.3.2"
[root@master ~]# brctl addif docker0 br0
[root@master ~]# brctl show
bridge name bridge id       STP enabled interfaces
docker0     8000.024245b7c2fd   no      br0
[root@master ~]# ip link set dev br0 up
[root@master ~]# ip link set dev docker0 up
[root@master ~]# ip addr
1: lo:  mtu 65536 qdisc noqueue state UNKNOWN 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: eth0:  mtu 1500 qdisc fq state UP qlen 1000
    link/ether 00:0c:29:97:92:e8 brd ff:ff:ff:ff:ff:ff
    inet 10.16.170.10/24 brd 255.255.255.0 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe97:92e8/64 scope link
       valid_lft forever preferred_lft forever
3: docker0:  mtu 1500 qdisc noqueue state UP
    link/ether 02:42:45:b7:c2:fd brd ff:ff:ff:ff:ff:ff
    inet 192.168.18.1/24 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:45ff:feb7:c2fd/64 scope link
       valid_lft forever preferred_lft forever
5: vethcff8026@if4:  mtu 1500 qdisc noqueue master docker0 state UP
    link/ether 32:4a:f5:b7:33:f7 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::304a:f5ff:feb7:33f7/64 scope link
       valid_lft forever preferred_lft forever
6: ovs-system:  mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether 8a:ac:8e:a1:68:2b brd ff:ff:ff:ff:ff:ff
7: br0:  mtu 1500 qdisc noqueue master docker0 state UNKNOWN qlen 1000
    link/ether 82:ae:47:8e:30:4d brd ff:ff:ff:ff:ff:ff
    inet6 fe80::80ae:47ff:fe8e:304d/64 scope link
       valid_lft forever preferred_lft forever
8: gre0@NONE:  mtu 1476 qdisc noop state DOWN qlen 1000
    link/gre 0.0.0.0 brd 0.0.0.0
9: gretap0@NONE:  mtu 1462 qdisc noop state DOWN qlen 1000
    link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
10: gre_sys@NONE:  mtu 65490 qdisc fq master ovs-system state UNKNOWN qlen 1000
    link/ether aa:3a:19:78:48:89 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::a83a:19ff:fe78:4889/64 scope link
       valid_lft forever preferred_lft forever
[root@master ~]#  ip route add 192.168.42.0/24 dev docker0
[root@master ~]# docker run -itd --name c1 docker.io/centos '/bin/bash'
WARNING: IPv4 forwarding is disabled. Networking will not work.
a326fb2eae1ecf1c0b1a26b4b947f20eb44864fc5232e253b582c8c7bb50522a
[root@master ~]# vim /etc/sysctl.conf
[root@master ~]# sysctl -p
net.core.default_qdisc = fq
net.ipv4.tcp_congestion_control = bbr
net.ipv4.ip_forward = 1
[root@master ~]#
(3) docker node端配置如下
[root@node1 ~]# service openvswitch start  && chkconfig openvswitch on
[root@node1 ~]# brctl show
bridge name bridge id       STP enabled interfaces
docker0     8000.02429f5f947d   no
[root@node1 ~]#  ovs-vsctl add-br br0
[root@node1 ~]#  ovs-vsctl add-port br0 gre0 -- set interface gre0 type=gre option:remote_ip=10.16.170.10
这里如果写错ip 修改的话需要删除网桥: ovs-vsctl  del-br br0

[root@node1 ~]# brctl addif docker0 br0
[root@node1 ~]# brctl show
bridge name bridge id       STP enabled interfaces
docker0     8000.02429f5f947d   no      br0
[root@node1 ~]#
[root@node1 ~]# ip link set dev br0 up
[root@node1 ~]# ip link set dev docker0 up
[root@node1 ~]# ip route add 192.168.18.0/24 dev docker0
[root@node1 ~]# brctl show
bridge name bridge id       STP enabled interfaces
docker0     8000.02429f5f947d   no      br0
[root@node1 ~]# ovs-vsctl show
f0be12f7-1aa7-4b93-8d4f-5511b56efec7
    Bridge "br0"
        Port "gre0"
            Interface "gre0"
                type: gre
                options: {remote_ip="10.16.170.10"}
        Port "br0"
            Interface "br0"
                type: internal
    ovs_version: "2.3.2"
[root@node1 ~]# echo 'net.ipv4.ip_forward = 1' >> /etc/sysctl.conf
[root@node1 ~]# sysctl -p
[root@node1 ~]# docker run -itd --name c2 docker.io/centos '/bin/bash'
c9414017f86e6c362b9481ceffc658275b3557cf0991e84853066d4eccb37b0f
[root@node1 ~]#
(4) 测试
[root@node1 ~]# docker attach c941
[root@c9414017f86e /]# ping -c1 192.168.18.1
PING 192.168.18.1 (192.168.18.1) 56(84) bytes of data.
64 bytes from 192.168.18.1: icmp_seq=1 ttl=64 time=5.19 ms

--- 192.168.18.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 5.194/5.194/5.194/0.000 ms
[root@c9414017f86e /]# ping -c1 192.168.18.2
PING 192.168.18.2 (192.168.18.2) 56(84) bytes of data.
64 bytes from 192.168.1.2: icmp_seq=1 ttl=63 time=2.74 ms

--- 192.168.18.2 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 2.742/2.742/2.742/0.000 ms
[root@master ~]#docker exec -it 34fb bash 选择一台容器进入 
[root@34fb4017f86 /]# ping -c1 192.168.42.1
PING 192.168.42.1 (192.168.42.1) 56(84) bytes of data.
64 bytes from 192.168.42.1: icmp_seq=1 ttl=64 time=0.051 ms

--- 192.168.42.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.051/0.051/0.051/0.000 ms

ok 搞定