转自：https://www.cnblogs.com/jsonhc/p/7852530.html
swarm集群配置完成后，查看一些基本的信息：
[root@manager1 ~]# docker-machine ls NAME ACTIVE DRIVER STATE URL SWARM DOCKER ERRORS manager1 - generic Running tcp://192.168.101.14:2376 v17.09.0-ce work1 - generic Running tcp://192.168.101.15:2376 v17.10.0-ce
查看节点信息：
[root@manager1 ~]# docker node ls ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS 4ecjeeu8273dzsmfta7u6op9t * manager1 Ready Active Leader sn7c5u5wtupgt3qpz22o117hl work1 Ready Active
如果需要更新详细的查看节点信息：
[root@manager1 ~]# docker node inspect --pretty manager1 ID: 4ecjeeu8273dzsmfta7u6op9t Hostname: manager1 Joined at: 2017-11-15 18:28:21.103210247 +0000 utc Status: State: Ready Availability: Active Address: 192.168.101.14 Manager Status: Address: 192.168.101.14:2377 Raft Status: Reachable Leader: Yes Platform: Operating System: linux Architecture: x86_64 Resources: CPUs: 2 Memory: 3.686GiB Plugins: Log: awslogs, fluentd, gcplogs, gelf, journald, json-file, logentries, splunk, syslog Network: bridge, host, macvlan, null, overlay Volume: local Engine Version: 17.09.0-ce Engine Labels: - provider=generic TLS Info: TrustRoot: -----BEGIN CERTIFICATE----- MIIBazCCARCgAwIBAgIUPDGTCzw2cZelyvysFW+jcF3PcQMwCgYIKoZIzj0EAwIw EzERMA8GA1UEAxMIc3dhcm0tY2EwHhcNMTcxMTE1MTgyMzAwWhcNMzcxMTEwMTgy MzAwWjATMREwDwYDVQQDEwhzd2FybS1jYTBZMBMGByqGSM49AgEGCCqGSM49AwEH A0IABNyMg4cqG1XaXB6g5PbNGxjishle1cPF9t0kn5LbRKwh+IGwDZD2fdbli2bk 9fzVQVWCj3aZzCyyVSFxZ30+cPWjQjBAMA4GA1UdDwEB/wQEAwIBBjAPBgNVHRMB Af8EBTADAQH/MB0GA1UdDgQWBBTElfvEWZqpfIfCYCr+Vn6peYGOPDAKBggqhkjO PQQDAgNJADBGAiEAh44+/Ns5T+MwiD49jXmIpr7mz/8qyMEvFDtk55j5eQ0CIQCP HEbLBRkJWxqNs6p5O+emfvIVpFHuy/X8K6tDF7qmiw== -----END CERTIFICATE----- Issuer Subject: MBMxETAPBgNVBAMTCHN3YXJtLWNh Issuer Public Key: MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE3IyDhyobVdpcHqDk9s0bGOKyGV7Vw8X23SSfkttErCH4gbANkPZ91uWLZuT1/NVBVYKPdpnMLLJVIXFnfT5w9Q==
现在利用docker service命令来创建服务：
[root@manager1 ~]# docker service create --name web --replicas 2 nginx oq2jsjc4zhwtpcwqqd2whj701 Since --detach=false was not specified, tasks will be created in the background. In a future release, --detach=false will become the default.
其中的参数：--name表示创建服务的名称，--replicas表示创建的副本数，nginx是镜像
查看创建好的service：
[root@manager1 ~]# docker service ls ID NAME MODE REPLICAS IMAGE PORTS oq2jsjc4zhwt web replicated 2/2 nginx:latest
查看service服务在节点的运行情况：
[root@manager1 ~]# docker service ps web ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS rk7pyq7pr49b web.1 nginx:latest work1 Running Running 7 seconds ago w3orhk7uzvzy web.2 nginx:latest manager1 Running Running 7 seconds ago
如果在创建的过程中出现如下报错：
[root@manager1 ~]# docker service ps web ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS klcan0r46jih web.1 nginx:latest work1 Ready Preparing 3 seconds ago ypx26zy1gp63 \_ web.1 nginx:latest work1 Shutdown Rejected 3 seconds ago "No such image: nginx:latest@s…" dy51asan25pf web.2 nginx:latest manager1 Running Running 18 seconds ago
work1节点上没有相应的镜像，导致启动失败，可能的原因之一：work1节点使用的默认的官方镜像源，所以下载缓慢，导致失败，解决办法：将work1节点配置镜像加速器重启docker服务就行
如果需要详细查看service信息：
[root@manager1 ~]# docker service inspect --pretty web ID: oq2jsjc4zhwtpcwqqd2whj701 Name: web Service Mode: Replicated Replicas: 2 Placement: UpdateConfig: Parallelism: 1 On failure: pause Monitoring Period: 5s Max failure ratio: 0 Update order: stop-first RollbackConfig: Parallelism: 1 On failure: pause Monitoring Period: 5s Max failure ratio: 0 Rollback order: stop-first ContainerSpec: Image: nginx:latest@sha256:9fca103a62af6db7f188ac3376c60927db41f88b8d2354bf02d2290a672dc425 Resources: Endpoint Mode: vip
如果需要访问容器提供的服务，需要为容器进行映射端口：
[root@manager1 ~]# docker service update --publish-add 8080:80 web web
使用命令update进行对服务的修改，更新等等操作
[root@manager1 ~]# docker service ps web ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS jzq72hlu434g web.1 nginx:latest work1 Running Running less than a second ago rk7pyq7pr49b \_ web.1 nginx:latest work1 Shutdown Shutdown 1 second ago ys5voif2df7f web.2 nginx:latest manager1 Running Running 2 seconds ago w3orhk7uzvzy \_ web.2 nginx:latest manager1 Shutdown Shutdown 3 seconds ago
[root@manager1 ~]# docker service ls ID NAME MODE REPLICAS IMAGE PORTS oq2jsjc4zhwt web replicated 2/2 nginx:latest *:8080->80/tcp
然后进行访问web服务：
这里创建的服务在节点manager1和worl1上（192.168.101.14、192.168.101.15），不指定为什么创建的service一直没有实现负载均衡，一直只是manager1节点能够提供访问，这个问题等待解决
上面可以看出service由manager1、work1两个节点提供，现在将其中的某一个节点进行下线：
[root@manager1 ~]# docker node update --availability drain work1 work1 [root@manager1 ~]# docker node ls ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS 4ecjeeu8273dzsmfta7u6op9t * manager1 Ready Active Leader sn7c5u5wtupgt3qpz22o117hl work1 Ready Drain
节点的availability的值可以显示节点的状态（active表示活跃在线，drain表示下线不提供服务或者处于维护状态）
将节点wrok1下线后，查看服务的replicas数量：
[root@manager1 ~]# docker service ls ID NAME MODE REPLICAS IMAGE PORTS oq2jsjc4zhwt web replicated 2/2 nginx:latest *:8080->80/tcp
可以看见service web的replicas并没有减少：
[root@manager1 ~]# docker service ps web ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS o0p9zt3su44g web.1 nginx:latest manager1 Running Running about a minute ago jzq72hlu434g \_ web.1 nginx:latest work1 Shutdown Shutdown about a minute ago rk7pyq7pr49b \_ web.1 nginx:latest work1 Shutdown Shutdown 6 minutes ago ys5voif2df7f web.2 nginx:latest manager1 Running Running 6 minutes ago w3orhk7uzvzy \_ web.2 nginx:latest manager1 Shutdown Shutdown 6 minutes ago
而提供服务的节点由之前的manager1和worlk1共同提供变成了只由节点manager1提供：
现在将work1节点进行更改为active：
[root@manager1 ~]# docker node update --availability active work1 work1 [root@manager1 ~]# docker node ls ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS 4ecjeeu8273dzsmfta7u6op9t * manager1 Ready Active Leader sn7c5u5wtupgt3qpz22o117hl work1 Ready Active
当work1节点上线后，但是work1并没有抢回提供服务：
[root@manager1 ~]# docker service ps web ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS o0p9zt3su44g web.1 nginx:latest manager1 Running Running 4 minutes ago jzq72hlu434g \_ web.1 nginx:latest work1 Shutdown Shutdown 4 minutes ago rk7pyq7pr49b \_ web.1 nginx:latest work1 Shutdown Shutdown 9 minutes ago ys5voif2df7f web.2 nginx:latest manager1 Running Running 9 minutes ago w3orhk7uzvzy \_ web.2 nginx:latest manager1 Shutdown Shutdown 9 minutes ago
现在将service的replicas进行伸缩或者扩展，这里将replicas增加到3（现在数量为2）
[root@manager1 ~]# docker service scale web=3 web scaled to 3
[root@manager1 ~]# docker service ps web ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS o0p9zt3su44g web.1 nginx:latest manager1 Running Running 6 minutes ago jzq72hlu434g \_ web.1 nginx:latest work1 Shutdown Shutdown 6 minutes ago rk7pyq7pr49b \_ web.1 nginx:latest work1 Shutdown Shutdown 11 minutes ago ys5voif2df7f web.2 nginx:latest manager1 Running Running 11 minutes ago w3orhk7uzvzy \_ web.2 nginx:latest manager1 Shutdown Shutdown 11 minutes ago g0liotj1z9j6 web.3 nginx:latest work1 Running Running 1 second ago
可以看见work1节点又开始为web提供服务了
删除掉上面创建的服务，重新创建新的服务，使用--publish：
[root@manager1 ~]# docker service rm web web
