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1：前言
在 docker1.12 版本之前，众所周知 dokcer 本身只能单机上运行，而集群则要依赖 mesos、kubernetes、swarm 等集群管理方案。其中 swarm 是 docker 公司自己的容器集群管理工具，在当时的热度还是低于前两者。docker1.12.0 版本发布中，Docker 公司出于战略眼光，将 swarm 集成到 docker-engine 中，使 docker 内置了集群解决方案。于是 swarm 这个“亲儿子”的江湖地位迅速提升，在 docker 集群方案中与 mesos，k8s 形成三足鼎立之势，在未来则大有赶超之势。
2：规划
IP 主机名 角色
10.10.32.245 swarm1 swarm manager
10.10.32.246 swarm2 worker node
10.10.32.247 swarm3 worker node
10.10.32.248 swarm4 worker node
3：集群通信原理
通过 /usr/lib/system.d/system/docker.service 配置开启 2375 管理端口
ExecStart=/usr/bin/dockerd -s overlay –insecure-registry registry.cntv.net -H tcp://0.0.0.0:2375 -H unix:///va
每个 node 节点上，都开启 2375 远程管理端口，swarm 集群管理通过 2375 管理端口来执行
4：swarm 调度原理
swarm 中实现调度功能的主要是 scheduler 模块，其中包括 Filter 和 strategy。
Filter：根据下发的任务的资源需求，用来过滤节点，从集群所有节点中找出满足条件的节点（比如资源足够，节点正常等等）
Strategy：用来在过滤出的节点中根据策略选择一个最优的节点（比如对找出的节点进行对比，找到资源最多的节点等等）
5：swarm 集群创建
（1）初始化 manager 节点
10.10.32.245
$docker swarm init --advertise-addr 10.10.32.245 Swarm initialized: current node (b73yii7s7rn321ejz8n3ch7ay) is now a manager. To add a worker to this swarm, run the following command: docker swarm join \ --token SWMTKN-1-2z3obrzww2zcnwaiq5dzocpmvz9kty25usroy3gh3xux0l32uo-8dxurdbms8yli2crdxbmyk7y2 \ 10.10.32.245:2377 To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.（2）manage 查看节点 swarm 状态
10.10.32.245
$docker info Swarm: active NodeID: ax13h89zlb5dqw980ddo1ox4f Is Manager: true ClusterID: d5nam0mink4wdk506o1ybbs9e Managers: 1 Nodes: 1 （3）manage 查看 swarm 节点
10.10.32.245
$ docker node ls ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS ax13h89zlb5dqw980ddo1ox4f * swarm1 Ready Active Leader （4）node 节点加入 swarm 集群
10.10.32.246 10.10.32.247 10.10.32.248
$ docker swarm join-token manager #manage 上查询加入命令及 token To add a manager to this swarm, run the following command: docker swarm join \ --token SWMTKN-1-2z3obrzww2zcnwaiq5dzocpmvz9kty25usroy3gh3xux0l32uo-8dxurdbms8yli2crdxbmyk7y2 \ 10.10.32.245:2377 $ docker swarm join \ --token SWMTKN-1-2z3obrzww2zcnwaiq5dzocpmvz9kty25usroy3gh3xux0l32uo-8dxurdbms8yli2crdxbmyk7y2 \ 10.10.32.245:2377 This node joined a swarm as a worker （5）manage 查看 swarm 节点
$ docker node ls ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS 03b5w49n7uz663xwjuof3dsk0 swarm4 Ready Active 0g039jomhpad819a39yvkow6y swarm2 Ready Active 4kos85v5z6jh6lahwv8yjpku8 swarm3 Ready Active ax13h89zlb5dqw980ddo1ox4f * swarm1 Ready Active Leader （6）使节点离开集群
$ docker swarm leave Node left the swarm.6：在 swarm 集群上创建服务
（1）创建服务
$docker service create --network net3 --replicas 4 -p 8099:80 --name time-php registry.cntv.net/heqin/tvtime-php:v0.85dongsi bdkwsgchcydz5ixatrbiyr1fx（2）查看服务
$ docker service ls # 查看服务 ID NAME REPLICAS IMAGE COMMAND bdkwsgchcydz time-php 4/4 registry.cntv.net/heqin/tvtime-php:v0.85dongsi
$docker service ps time-php # 查看服务的实例 ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR d15ambrdd7pyi22951vi497xa time-php.1 registry.cntv.net/heqin/tvtime-php:v0.85dongsi swarm4 Running Running 5 minutes ago 3wtmmggo65cmyutg7zwikb94s time-php.2 registry.cntv.net/heqin/tvtime-php:v0.85dongsi swarm3 Running Running 5 minutes ago 5ulbhndwgswpicx8g62af8k5z time-php.3 registry.cntv.net/heqin/tvtime-php:v0.85dongsi swarm2 Running Running 5 minutes ago 4b9rh8aiwfi88xrdgmyss9ili time-php.4 registry.cntv.net/heqin/tvtime-php:v0.85dongsi swarm2 Running Running 5 minutes ago $docker service inspect time-php # 查看服务的详细信息 [ { "ID": "bdkwsgchcydz5ixatrbiyr1fx", "Version": { "Index": 3074 }, "CreatedAt": "2016-08-31T01:41:18.892483521Z", "UpdatedAt": "2016-08-31T01:41:18.909164422Z", "Spec": { "Name": "time-php", "TaskTemplate": { "ContainerSpec": { "Image": "registry.cntv.net/heqin/tvtime-php:v0.85dongsi" }, "Resources": { "Limits": {}, "Reservations": {} }, "RestartPolicy": { "Condition": "any", "MaxAttempts": 0 }, "Placement": {} }, "Mode": { "Replicated": { "Replicas": 4 } }, "UpdateConfig": { "Parallelism": 1, "FailureAction": "pause" }, "Networks": [ { "Target": "d83qc9rgkkj1ws8kvmod4x759" } ], "EndpointSpec": { "Mode": "vip", "Ports": [ { "Protocol": "tcp", "TargetPort": 80, "PublishedPort": 8099 } ] } }, "Endpoint": { "Spec": { "Mode": "vip", "Ports": [ { "Protocol": "tcp", "TargetPort": 80, "PublishedPort": 8099 } ] }, "Ports": [ { "Protocol": "tcp", "TargetPort": 80, "PublishedPort": 8099 } ], "VirtualIPs": [ { "NetworkID": "biu7m9hi8fgbbihfzg48whxqi", "Addr": "10.255.0.19/16" }, { "NetworkID": "d83qc9rgkkj1ws8kvmod4x759", "Addr": "10.88.0.2/24" } ] }, "UpdateStatus": { "StartedAt": "0001-01-01T00:00:00Z", "CompletedAt": "0001-01-01T00:00:00Z" } } ] （3）扩展服务实例数
$ docker service scale time-php=10 time-php scaled to 10 $ docker service lsID NAME REPLICAS IMAGE bdkwsgchcydz time-php 6/6 registry.cntv.net/heqin/tvtime-php:v0.85dongsi （4）更新服
$ docker service update --image registry.cntv.net/heqin/tvtime-php:v0.84xidan --log-driver=syslog time-php time-php $ docker service lsID NAME REPLICAS IMAGE bdkwsgchcydz time-php 6/6 registry.cntv.net/heqin/tvtime-php:v0.84xidan
（5）删除服务
$docker service rm time-php time-php 7：网络
（1）查看容器网络
$docker network lsNETWORK ID NAME DRIVER SCOPE a17f16650bf9 bridge bridge local # 容器使用独立网络 Namespace，连接 docker0 虚拟网卡（默认模式）f1c102babcf8 host host local # 容器与主机共享网络 Namespace，拥有主机相同网卡 b6a2efce65ef none null local # 容器没有任何网卡，适合不需要与外部通信的容器 asa2hv41mtci ingress overlay swarm #swarm 集群的的 overlay 网络，容器可以跨主机网络通信注：上面三个网络是 docker 安装后默认带的三个网络，第四个 overlay 网络是启动 swarm 之后默认创建的 overlay 网络。
（2）查看 overlay 网络信息
$docker network inspect ingress [ { "Name": "ingress", "Id": "asa2hv41mtci2qzjkaonusnc8", "Scope": "swarm", "Driver": "overlay", "EnableIPv6": false, "IPAM": { "Driver": "default", "Options": null, "Config": [ { "Subnet": "10.255.0.0/16", "Gateway": "10.255.0.1" } ] }, "Internal": false, "Containers": null, "Options": { "com.docker.network.driver.overlay.vxlanid_list": "258" }, "Labels": null } ]（3）创建自定义的 overlay 网络
$docker network create --driver=overlay --subnet=10.88.0.0/24 --gateway=10.88.0.1 net3 c654pb76q9jnni5bpdvd34rg4 $docker network lsNETWORK ID NAME DRIVER SCOPE c654pb76q9jn net3 overlay swarm $docker network inspect net3 [ { "Name": "net3", "Id": "c654pb76q9jnni5bpdvd34rg4", "Scope": "swarm", "Driver": "overlay", "EnableIPv6": false, "IPAM": { "Driver": "default", "Options": null, "Config": [ { "Subnet": "10.88.0.0/24", "Gateway": "10.88.0.1" } ] }, "Internal": false, "Containers": null, "Options": { "com.docker.network.driver.overlay.vxlanid_list": "258" }, "Labels": null } 注：在 manage 上创建 overlay 网络后，各 node 上并没有同步创建该网络，只有当使用该 overlay 网络的容器在 node 节点上运行时，才会在 node 节点上自动创建, 容器删除后，网络也会在 node 节点上删除。
（4）将容器绑定到自定义的网络中
$docker service create --network net3 --replicas 4 --name time-php registry.cntv.net/heqin/tvtime-php:v0.85dongsi 5qiv4hhv7ra5p65fpq2v6ok0x $docker service ls5qiv4hhv7ra5 time-php 4/4 registry.cntv.net/heqin/tvtime-php:v0.85dongsi $docker service ps time-php ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR 529kuyazgxxl8l0eds4f740nu time-php.1 registry.cntv.net/heqin/tvtime-php:v0.85dongsi swarm3 Running Running 32 seconds ago brdelpbuwm3p9cujy6k78cpzo time-php.2 registry.cntv.net/heqin/tvtime-php:v0.85dongsi swarm3 Running Running 33 seconds ago 3csp6fmrsg5cvski270732q98 time-php.3 registry.cntv.net/heqin/tvtime-php:v0.85dongsi swarm2 Running Running 34 seconds ago 2ismj5zt9o3t2hfe1j1lx7dcw time-php.4 registry.cntv.net/heqin/tvtime-php:v0.85dongsi swarm4 Running Running 33 seconds ago进入 swarm3，可以看到 net3 网络下有两个容器。
$docker docker network inspect net3 [ { "Name": "net3", "Id": "d83qc9rgkkj1ws8kvmod4x759", "Scope": "swarm", "Driver": "overlay", "EnableIPv6": false, "IPAM": { "Driver": "default", "Options": null, "Config": [ { "Subnet": "10.88.0.0/24", "Gateway": "10.88.0.1" } ] }, "Internal": false, "Containers": { "d465611683b69f20c28ec9eb276a9e4088867e35508ecf2bf28c07c5d3e1b33a": { "Name": "time-php.1.529kuyazgxxl8l0eds4f740nu", "EndpointID": "ca667c89550f88eabf54eeaaaa3c55c678ec8184f121fc845bbaab1cd4be20ff", "MacAddress": "02:42:0a:58:00:05", "IPv4Address": "10.88.0.5/24", "IPv6Address": "" }, "d8fa64c4f8357418304ed1f19a049e4aac196c94ef50a27a0686ebe4ee734225": { "Name": "time-php.2.brdelpbuwm3p9cujy6k78cpzo", "EndpointID": "ab45bcf8e73d114e9bdf97cac128750a6c7a073149783746a9962c6cd4c599a8", "MacAddress": "02:42:0a:58:00:06", "IPv4Address": "10.88.0.6/24", "IPv6Address": "" } }, "Options": { "com.docker.network.driver.overlay.vxlanid_list": "257" }, "Labels": {} } 用 swarm3 的容器去 ping swarm2 主机上的容器，是可以 ping 通的
$docker exec -it d8fa64c4f835 ping 10.88.0.3 PING 10.88.0.3 (10.88.0.3) 56(84) bytes of data. 64 bytes from 10.88.0.3: icmp_seq=1 ttl=64 time=0.611 ms 64 bytes from 10.88.0.3: icmp_seq=2 ttl=64 time=5.45 ms 64 bytes from 10.88.0.3: icmp_seq=3 ttl=64 time=0.439 ms 64 bytes from 10.88.0.3: icmp_seq=4 ttl=64 time=0.586 ms 64 bytes from 10.88.0.3: icmp_seq=5 ttl=64 time=0.603 ms 8：swarm 基本命令
swarm 集群创建与管理
docker swarm Command
Commands:
init Initialize a swarm
join Join a swarm as a node and/or manager
join-token Manage join tokens
update Update the swarm
leave Leave a swarm
swarm 服务创建与管理
docker service Command
Commands:
create Create a new service
inspect Display detailed information on one or more services
ps List the tasks of a service
ls List services
rm Remove one or more services
scale Scale one or multiple services
update Update a service
swarm 服务创建选项
docker service create [OPTIONS] IMAGE
Options:
–constraint value Placement constraints (default [])
–container-label value Container labels (default [])
–endpoint-mode string Endpoint mode (vip or dnsrr)
-e, –env value Set environment variables (default [])
–help Print usage
-l, –label value Service labels (default [])
–limit-cpu value Limit CPUs (default 0.000)
–limit-memory value Limit Memory (default 0 B)
–log-driver string Logging driver for service
–log-opt value Logging driver options (default [])
–mode string Service mode (replicated or global) (default “replicated”)
–mount value Attach a mount to the service
–name string Service name
–network value Network attachments (default [])
-p, –publish value Publish a port as a node port (default [])
–replicas value Number of tasks (default none)
–reserve-cpu value Reserve CPUs (default 0.000)
–reserve-memory value Reserve Memory (default 0 B)
–restart-condition string Restart when condition is met (none, on-failure, or any)
–restart-delay value Delay between restart attempts (default none)
–restart-max-attempts value Maximum number of restarts before giving up (default none)
–restart-window value Window used to evaluate the restart policy (default none)
–stop-grace-period value Time to wait before force killing a container (default none)
–update-delay duration Delay between updates
–update-failure-action string Action on update failure (pause|continue) (default “pause”)
–update-parallelism uint Maximum number of tasks updated simultaneously (0 to update all at once) (default 1)
-u, –user string Username or UID
9：利用 2375 端口远程管理
注：-H 指定远程地址和端口，即可在任意一台有 docker 客户端的机器远程操作 swarm 集群
$docker -H 10.00.32.245:2375 service lsID NAME REPLICAS IMAGE COMMAND 3e0ihi2lnnaa test_api 1/1 registry.cntv.net/heqin/api-web:1.1 5mdqw6r53tom test_apimem 1/1 registry.cntv.net/heqin/memcache-1.4 5ucxo9wqywo9 test_tomcatmem 1/1 registry.cntv.net/heqin/memcache-1.4 cjd1z14ug28g HQtest_tvtime 5/5 registry.cntv.net/heqin/tvtime-php:v0.85dongsi ex4mahzt5k8u test_tomcat 1/1 registry.cntv.net/heqin/jdk7-tomcat7.0.52:201608011wq10：swarm 与 mesos 对比
（1）：部署配置简单，集群管理便利，但是没有 web 管理界面
（2）：每个节点无需手动安装 agent，集群间只需要通过暴露 tcp：//2375 端口来保证节点间的通信。
（3）：无需 bamboo 来做负载均衡，swarm 集群使用 IPVS 负载均衡
（4）：无需 marathon、chrons 等调度组件，swarm 内置调度模块。
更多 Docker 相关教程见以下内容：
Docker 安装应用(CentOS 6.5_x64) http://www.linuxidc.com/Linux/2014-07/104595.htm
Ubuntu 14.04 安装 Docker http://www.linuxidc.com/linux/2014-08/105656.htm
Ubuntu 使用 VNC 运行基于 Docker 的桌面系统 http://www.linuxidc.com/Linux/2015-08/121170.htm
阿里云 CentOS 6.5 模板上安装 Docker http://www.linuxidc.com/Linux/2014-11/109107.htm
Ubuntu 15.04 下安装 Docker http://www.linuxidc.com/Linux/2015-07/120444.htm
在 Ubuntu Trusty 14.04 (LTS) (64-bit)安装 Docker http://www.linuxidc.com/Linux/2014-10/108184.htm
在 Ubuntu 15.04 上如何安装 Docker 及基本用法 http://www.linuxidc.com/Linux/2015-09/122885.htm
Ubuntu 16.04 上 Docker 使用手记 http://www.linuxidc.com/Linux/2016-12/138490.htm
Docker 的详细介绍：请点这里
Docker 的下载地址：请点这里
本文永久更新链接地址：http://www.linuxidc.com/Linux/2017-03/142151.htm
