前面已经学习了如何部署Service吗，也验证了swarm的failover特性，下面我们要学习的是如何访问Service。
下面我们删除之前的Service，重新部署一个Service
内部访问Service
root@host03:~# docker service rm web_server # 删除之前的Service web_server
web_server
root@host03:~# docker service create --name web_server --replicas=2 httpd # 创建新的Service，并设置副本数为2
1hgm1w94dvuxlbsen9lmsefvz
overall progress: 2 out of 2 tasks
1/2: running [==================================================>]
2/2: running [==================================================>]
verify: Service converged
root@host03:~# docker service ps web_server # 查看新建Service 容器分布情况
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
s4o9mtd8xvqe web_server.1 httpd:latest host01 Running Running 12 seconds ago
kq66bz6omujf web_server.2 httpd:latest host02 Running Running 12 seconds ago
root@host01:~# docker inspect web_server.1.s4o9mtd8xvqe8yqcnbyuom26f | jq .[0].NetworkSettings # 查看某容器内部IP地址
{
"Bridge": "",
"SandboxID": "407fde9cdf85507b7e5c635ea3313e41e6ef54da9242837e292526cf0398000d",
"HairpinMode": false,
"LinkLocalIPv6Address": "",
"LinkLocalIPv6PrefixLen": 0,
"Ports": {
"80/tcp": null
},
"SandboxKey": "/var/run/docker/netns/407fde9cdf85",
"SecondaryIPAddresses": null,
"SecondaryIPv6Addresses": null,
"EndpointID": "a10f1d6f81f492f8b7911997a0837d499f8bbc733c274c955e479c0fedeec433",
"Gateway": "172.17.0.1",
"GlobalIPv6Address": "",
"GlobalIPv6PrefixLen": 0,
"IPAddress": "172.17.0.2",
"IPPrefixLen": 16,
"IPv6Gateway": "",
"MacAddress": "02:42:ac:11:00:02",
"Networks": {
"bridge": {
"IPAMConfig": null,
"Links": null,
"Aliases": null,
"NetworkID": "d4b0862f06c8f2f16802b3fe9175743e7afdc2396322ff19e656bebca4d9a940",
"EndpointID": "a10f1d6f81f492f8b7911997a0837d499f8bbc733c274c955e479c0fedeec433",
"Gateway": "172.17.0.1",
"IPAddress": "172.17.0.2",
"IPPrefixLen": 16,
"IPv6Gateway": "",
"GlobalIPv6Address": "",
"GlobalIPv6PrefixLen": 0,
"MacAddress": "02:42:ac:11:00:02",
"DriverOpts": null
}
}
}
root@host01:~# curl http://172.17.0.2 # 内部访问验证
<html><body><h1>It works!</h1></body></html>
外部访问Service
root@host03:~# docker service update --publish-add 8080:80 web_server # 更新Service配置，添加端口映射，将容器的80端口映射到host的8080端口
web_server
overall progress: 2 out of 2 tasks
1/2: running [==================================================>]
2/2: running [==================================================>]
verify: Service converged
root@host03:~# curl http://10.12.31.211:8080 # 访问 host01 IP 验证外部访问
<html><body><h1>It works!</h1></body></html>
root@host03:~# curl http://10.12.31.212:8080 # 访问 host02 IP 验证外部访问
<html><body><h1>It works!</h1></body></html>
root@host03:~# curl http://10.12.31.213:8080 # 访问 host03 IP 验证外部访问（host03上没有容器，也可以访问成功，这是swarm的一个特性 routing mesh）
<html><body><h1>It works!</h1></body></html>