跨主机网络方案包括:node
docker
原生的overlay
和macvlan
。
第三方方案:经常使用的包括flannel、weave 和 calico
。linux
[root@linux-node1 ~]# docker run -d -p 8500:8500 -h consul --name consul progrium/consul -server -bootstrap [root@linux-node1 ~]# netstat -tulnp |grep 8500 tcp6 0 0 :::8500 :::* LISTEN 61092/docker-proxy- 容器启动后,能够经过 http://192.168.56.110:8500 访问 Consul。
接下来修改 node1 和 node2 的 docker daemon 的配置文件/var/lib/systemd/system/docker.service。 --cluster-store 指定 consul 的地址。 --cluster-advertise 告知 consul 本身的链接地址。 [root@linux-node1 ~]# cat /usr/lib/systemd/system/docker.service ...... ExecStart=/usr/bin/dockerd-current \ --add-runtime docker-runc=/usr/libexec/docker/docker-runc-current \ --default-runtime=docker-runc \ --exec-opt native.cgroupdriver=systemd \ --userland-proxy-path=/usr/libexec/docker/docker-proxy-current \ --seccomp-profile=/etc/docker/seccomp.json \ --cluster-store=consul://192.168.56.110:8500 \ --cluster-advertise=eth0:2376 \ $OPTIONS \ ...... [root@linux-node1 ~]# systemctl daemon-reload [root@linux-node1 ~]# systemctl restart docker node1 和 node2 将自动注册到 Consul 数据库中。
在 node1 中建立 overlay 网络 ov_net1: [root@linux-node1 ~]# docker network create -d overlay ov_net1 #-d overlay 指定 driver 为 overaly。 [root@linux-node1 ~]# docker network ls #查看当前网络 NETWORK ID NAME DRIVER SCOPE 8eb7fd71a52c bridge bridge local 6ba20168e34f host host local 4e896f9ac4bc none null local d9652d84d9de ov_net1 overlay global [root@linux-node2 ~]# docker network ls #查看当前网络 NETWORK ID NAME DRIVER SCOPE 94a3bc259414 bridge bridge local f8443f6cb8d2 host host local 2535ab8f3493 none null local d9652d84d9de ov_net1 overlay global node2 上也能看到 ov_net1。这是由于建立 ov_net1 时 node1 将 overlay 网络信息存入了 consul,node2 从 consul 读取到了新网络的数据。以后 ov_net 的任何变化都会同步到 node1 和 node2。 [root@linux-node1 ~]# docker network inspect ov_net1 #查看 ov_net1 的详细信息 [ { "Name": "ov_net1", "Id": "d9652d84d9de6d1145c77d0254c90164b968f72f2eda4aee43d56ab03f8530ed", "Created": "2018-04-19T21:50:29.128801226+08:00", "Scope": "global", "Driver": "overlay", "EnableIPv6": false, "IPAM": { "Driver": "default", "Options": {}, "Config": [ { "Subnet": "10.0.0.0/24", "Gateway": "10.0.0.1" } ] }, "Internal": false, "Attachable": false, "Containers": {}, "Options": {}, "Labels": {} } ]
[root@linux-node1 ~]# docker run -itd --name bbox1 --network ov_net1 busybox 340f748b06786c0f81c3e26dd9dbd820dafcdf73baa9232f02aece8d4c89a73b [root@linux-node1 ~]# docker exec bbox1 ip r #查看容器的网络配置 default via 172.18.0.1 dev eth1 10.0.0.0/24 dev eth0 scope link src 10.0.0.2 172.18.0.0/16 dev eth1 scope link src 172.18.0.2
bbox1
有两个网络接口eth0
和eth1
。eth0 IP
为10.0.0.2
,链接的是overlay
网络ov_net1
。eth1 IP 172.18.0.2
,容器的默认路由是走eth1
,eth1
是哪儿来的呢?docker其实,
docker
会建立一个bridge
网络 “docker_gwbridge
”,为全部链接到overlay
网络的容器提供访问外网的能力。数据库
[root@linux-node1 ~]# docker network ls NETWORK ID NAME DRIVER SCOPE 8eb7fd71a52c bridge bridge local 751bd423a345 docker_gwbridge bridge local 6ba20168e34f host host local 4e896f9ac4bc none null local d9652d84d9de ov_net1 overlay global [root@linux-node1 ~]# docker network inspect docker_gwbridge [ { "Name": "docker_gwbridge", "Id": "751bd423a345a7beaa6b4cbf2a69a7687e3d8b7e656952090c4b94aec54ec1b5", "Created": "2018-04-21T16:11:57.684140362+08:00", "Scope": "local", "Driver": "bridge", "EnableIPv6": false, "IPAM": { "Driver": "default", "Options": null, "Config": [ { "Subnet": "172.18.0.0/16", "Gateway": "172.18.0.1" } ] }, "Internal": false, "Attachable": false, "Containers": { "340f748b06786c0f81c3e26dd9dbd820dafcdf73baa9232f02aece8d4c89a73b": { "Name": "gateway_340f748b0678", "EndpointID": "64cd599aaa2408ca0a1e595264e727b09d26482ba4d2aa18d97862ed29e23b51", "MacAddress": "02:42:ac:12:00:02", "IPv4Address": "172.18.0.2/16", "IPv6Address": "" } }, "Options": { "com.docker.network.bridge.enable_icc": "false", "com.docker.network.bridge.enable_ip_masquerade": "true", "com.docker.network.bridge.name": "docker_gwbridge" }, "Labels": {} } ]
从
docker network inspect docker_gwbridge
输出可确认docker_gwbridge
的 IP 地址范围是172.18.0.0/16
,当前链接的容器就是bbox1(172.18.0.2)
。
并且此网络的网关就是网桥docker_gwbridge
的IP 172.17.0.1
。json
[root@linux-node1 ~]# ifconfig docker_gwbridge docker_gwbridge: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 172.18.0.1 netmask 255.255.0.0 broadcast 0.0.0.0 inet6 fe80::42:e4ff:feb8:22cb prefixlen 64 scopeid 0x20<link> ether 02:42:e4:b8:22:cb txqueuelen 0 (Ethernet) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 这样容器 bbox1 就能够经过 docker_gwbridge 访问外网。 [root@linux-node1 ~]# docker exec bbox1 ping -c 2 www.baidu.com PING www.baidu.com (58.217.200.112): 56 data bytes 64 bytes from 58.217.200.112: seq=0 ttl=127 time=32.465 ms 64 bytes from 58.217.200.112: seq=1 ttl=127 time=32.754 ms --- www.baidu.com ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 32.465/32.609/32.754 ms
[root@linux-node2 ~]# docker run -itd --name bbox2 --network ov_net1 busybox [root@linux-node2 ~]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 68c81b90fb86 busybox "sh" 2 days ago Up 2 days bbox2 [root@linux-node2 ~]# docker exec bbox2 ip r default via 172.18.0.1 dev eth1 10.0.0.0/24 dev eth0 scope link src 10.0.0.3 172.18.0.0/16 dev eth1 scope link src 172.18.0.2 ##bbox2 IP 为 10.0.0.3,能够直接 ping bbox1 [root@linux-node2 ~]# docker exec bbox2 ping -c 3 bbox1 PING bbox1 (10.0.0.2): 56 data bytes 64 bytes from 10.0.0.2: seq=0 ttl=64 time=154.064 ms 64 bytes from 10.0.0.2: seq=1 ttl=64 time=0.789 ms 64 bytes from 10.0.0.2: seq=2 ttl=64 time=0.539 ms --- bbox1 ping statistics --- 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max = 0.539/51.797/154.064 ms
docker
会为每一个overlay
网络建立一个独立的network namespace
,其中会有一个linux bridge br0
,endpoint
仍是由veth pair
实现,一端链接到容器中(即 eth0
),另外一端链接到namespace
的br0
上。bootstrap
br0
除了链接全部的endpoint
,还会链接一个vxlan
设备,用于与其余host
创建vxlan tunnel
。容器之间的数据就是经过这个tunnel
通讯的。逻辑网络拓扑结构如图所示:网络
不一样的
overlay
网络是相互隔离的。咱们建立第二个overlay
网络ov_net2
并运行容器bbox3
tcp
[root@linux-node1 ~]# docker run -itd --name bbox3 --network ov_net2 busybox 946def609a7b183f68b8398b35fd3f72dc28bff47cc2ba63467f266fde297d5a [root@linux-node1 ~]# docker exec -it bbox3 ip r default via 172.18.0.1 dev eth1 10.0.1.0/24 dev eth0 scope link src 10.0.1.2 ##bbox3的ip为10.0.1.2 172.18.0.0/16 dev eth1 scope link src 172.18.0.4 [root@linux-node1 ~]# docker exec -it bbox3 ping -c 2 10.0.0.3 #bbox3没法ping通bbox2 PING 10.0.0.3 (10.0.0.3): 56 data bytes ^C --- 10.0.0.3 ping statistics --- 2 packets transmitted, 0 packets received, 100% packet loss 若是要实现 bbox3 与 bbox2 通讯,能够将 bbox3 也链接到 ov_net1。 [root@linux-node1 ~]# docker network connect ov_net1 bbox3 [root@linux-node1 ~]# docker exec -it bbox3 ping -c 2 10.0.0.3 PING 10.0.0.3 (10.0.0.3): 56 data bytes 64 bytes from 10.0.0.3: seq=0 ttl=64 time=34.110 ms 64 bytes from 10.0.0.3: seq=1 ttl=64 time=0.745 ms --- 10.0.0.3 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 0.745/17.427/34.110 ms
docker
默认为overlay
网络分配 24 位掩码的子网(10.0.X.0/24)
,全部主机共享这个subnet
,容器启动时会顺序今后空间分配IP
。固然咱们也能够经过--subnet
指定 IP 空间。ide
[root@linux-node1 ~]# docker network create -d overlay --subnet 10.22.1.0/24 ov_net3a111191fa67e500015a2f3ab8166793d23f0adef4d66bfcee81166127915ff9f [root@linux-node1 ~]# docker network ls NETWORK ID NAME DRIVER SCOPE 8eb7fd71a52c bridge bridge local 751bd423a345 docker_gwbridge bridge local 6ba20168e34f host host local 4e896f9ac4bc none null local d9652d84d9de ov_net1 overlay global 667cc7ef7427 ov_net2 overlay global a111191fa67e ov_net3 overlay global