Overlay网络
Swarm中使用Overlay超级方便，不需要借助Consul等第三方存储服务来存储网络配置信息，Swarm内置类似的服务实现了
创建、应用、测试Overlay网络
root@node-40:~# docker network create -d overlay overlay_net
root@node-40:~# docker network ls -f "DRIVER=overlay"
NETWORK ID NAME DRIVER SCOPE
nun25wf6hnpv ingress overlay swarm
qa593lu08jbj overlay_net overlay swarm
创建Service并应用Overlay网络
root@node-40:~# docker service create --replicas 2 --network overlay_net --name ovl_my_web nginx:1.12检查Service创建启动情况
root@node-40:~# docker service ls ID NAME MODE REPLICAS IMAGE PORTS hy489wd5d6a7 ovl_my_web replicated 2/2 nginx:1.12此时Manager节点通知让Worker节点创建容器前，会先将overlay网络也同步过去
root@node-50:~# docker network ls -f "DRIVER=overlay" NETWORK ID NAME DRIVER SCOPE qa593lu08jbj overlay_net overlay swarm root@node-60:~# docker network ls -f "DRIVER=overlay" NETWORK ID NAME DRIVER SCOPE qa593lu08jbj overlay_net overlay swarm检查网络情况，由于nginx默认镜像中没有ping命令，所以更新下源，然后安装一下
root@node-50:~# docker exec -it ovl_my_web.2.7v624xu7otuh0zr0xd9rcmh8p bash root@03a2bd124965:/# apt-get update root@03a2bd124965:/# apt-get install iputils-ping测试网络情况 另外一台主机的容器: OK~
root@03a2bd124965:/etc/apt# ping -c1 -W1 ovl_my_web.1.kfm7cftwguhhqrso4blxhkzcq PING ovl_my_web.1.kfm7cftwguhhqrso4blxhkzcq (10.0.0.3) 56(84) bytes of data. 64 bytes from ovl_my_web.1.kfm7cftwguhhqrso4blxhkzcq.overlay_net (10.0.0.3): icmp_seq=1 ttl=64 time=1.12 ms
外网出口网关: OK~
root@03a2bd124965:/etc/apt# ping -c1 -W1 192.168.0.1
PING 192.168.0.1 (192.168.0.1) 56(84) bytes of data.
64 bytes from 192.168.0.1: icmp_seq=1 ttl=63 time=2.23 ms
测试公网访问: OK~
root@03a2bd124965:/etc/apt# ping -c1 -W1 www.baidu.com
PING www.a.shifen.com (220.181.112.244) 56(84) bytes of data.
64 bytes from 220.181.112.244 (220.181.112.244): icmp_seq=1 ttl=52 time=7.99 ms
OK，都是成功访问的，另外一台主机一样~
将现有的Service加入Overlay网络
此时Docker Swarm会删除重建容器来应用网络
root@node-40:~# docker service update --network-add overlay_net my_web
root@node-40:~# docker service ps -f "DESIRED-STATE=Running" my_web
重建后连接容器，检查网络情况
root@node-50:~# docker exec -it my_web.2.1ra3aua73egpw21rm3vuygm5t bash
root@fed217774102:/# ping ovl_my_web.1.kfm7cftwguhhqrso4blxhkzcq
PING ovl_my_web.1.kfm7cftwguhhqrso4blxhkzcq (10.0.0.3) 56(84) bytes of data.
64 bytes from ovl_my_web.1.kfm7cftwguhhqrso4blxhkzcq.overlay_net (10.0.0.3): icmp_seq=1 ttl=64 time=0.752 ms
root@fed217774102:/# ping my_web.5.ptrbadb8zvazekkr6bt99kwua
PING my_web.5.ptrbadb8zvazekkr6bt99kwua (10.0.0.7) 56(84) bytes of data.
64 bytes from my_web.5.ptrbadb8zvazekkr6bt99kwua.overlay_net (10.0.0.7): icmp_seq=1 ttl=64 time=1.00 ms
root@fed217774102:/# ping www.baidu.com
PING www.a.shifen.com (180.149.132.151) 56(84) bytes of data.
64 bytes from 180.149.132.151 (180.149.132.151): icmp_seq=1 ttl=53 time=6.82 ms
将Service移除Overlay网络
移除Service网络和添加一样，都是删除重建容器完成的
root@node-40:~# docker service update --network-rm overlay_net my_web
root@node-40:~# docker service ps -f "DESIRED-STATE=Running" my_web
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
mqp6a74k8mei my_web.1 nginx:1.12 node-60 Running Running 7 seconds ago
h72sj4v3d86f my_web.2 nginx:1.12 node-50 Running Running less than a second ago
j9x0gmll53dt my_web.3 nginx:1.12 node-60 Running Running less than a second ago
kv4ouucrgbf5 my_web.4 nginx:1.12 node-60 Running Running less than a second ago
m2e881khny4n my_web.5 nginx:1.12 node-50 Running Running 6 seconds ago
whg9nwv4icux my_web.6 nginx:1.12 node-50 Running Running less than a second ago