深入Cloud Foundry构架（一）

bigluo

<span class="Apple-style-span" style="color: rgb(69, 69, 69); font-family: 'Microsoft YaHei', simsun, Arial, sans-serif; line-height: 21px; -webkit-text-stroke-color: rgba(0, 0, 0, 0); -webkit-text-stroke-width: 1px; "><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; "><strong style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; 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padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: bold; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; "><br></strong></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; "></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; "><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">今年4月份，VMware突然发布了业内第一个开源的PaaS——CloudFoundry。几个关键字：开源、PaaS、VMware，如果你对云计算感兴趣，就冲着它的ApacheV2协议，如果不去GitHub拿它的代码好好研读一下，真有点对不起自己。笔者当时就是以这样的心态去研究它的代码，并把它部署在我们labs里面。发布至今的这几个月里，笔者一直关注它的演进，并从它的架构设计中获益良多，觉得有必要写出来与大家分享一下。由于个人知识、认知等原因，其中有些看法难免不成熟，大家可以直接批评、指教。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">本文会分为两个部份：第一部份主要介绍CloudFoundry的架构设计，从它所包含的模块介绍起，到各部份的消息流向，各模块如何协调合作；第二部份会在第一部份的基础上，以如何在你的数据中心里面用CloudFoundry部署一个私有PaaS为目标，把第一部分介绍到的架构知识使用起来。在本文，我不想简单的介绍如何使用CloudFoundry，这方面的文章，在SpringSource的官方博客里面有具体的介绍。如果需要这方面的介绍，笔者强烈建议到SpringSource或者CloudFoundry的官博找资料。另外，本文也不会具体介绍如何“贡献”Cloud Foundry，例如添加自己的Runtime，添加第三方的Service，这将会是两个很大的话题，以后我们会有专门的文章介绍，本文更多的算是入门级的架构介绍，可能会涉及到具体代码，但是只为更好地理解架构而服务。在第二部份，会简单介绍到如何用OrchestrationEngine来把CloudFoundry部署到IaaS上面，但是具体的实现方法将会放到介绍OrchestrationEngine的文章上面去，这里更多的是一种思想和BestPractice的分享。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">第一部份讲的很多内容，会引用Pat在10月12日的VMwareCloud Forum上面关于CloudFoundry架构的演讲。Pat是CloudFoundry Core的负责人，他的那次演讲很值得一听。如果你当时在场，并且理解他所说的内容，本部份可以选择直接跳过。我除了会把说的内容讲具体点外，不太可能可以讲得比他好。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><strong style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: bold; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; ">一、架构及模块</strong></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; "><strong style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: bold; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; "><br></strong></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; "></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; "><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">从总体地看，CloudFoundry的架构如下：</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><div class="timg" style="margin-top: 0px !important; margin-right: 0px !important; margin-bottom: 0px !important; margin-left: 0px !important; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; display: inline-block; position: relative; height: 391px; width: 568px; "><img class="qImg media" src="http://ww1.sinaimg.cn/mw600/88ca09aajw1dmgbe6ogebj.jpg" style="margin-top: 6px; margin-right: 1px; margin-bottom: 10px; margin-left: 1px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 5px; border-right-width: 5px; border-bottom-width: 5px; border-left-width: 5px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; display: block; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-color: rgb(225, 225, 218); border-right-color: rgb(225, 225, 218); border-bottom-color: rgb(225, 225, 218); border-left-color: rgb(225, 225, 218); max-width: 600px; "></div><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">这个架构图以及下文所用到的各模块架构图均来自Pat的PPT。从上图能够看到CloudFoundry主要有以下几大组件组成：</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">1、&nbsp; Router：顾名思义，Router组件在CloudFoundry中是对所有进来的Request进行路由。进入Router的request主要有两类：首先是来自VMCClient或者STS的，由CloudFoundry使用者发出的，管理型指令。例如：列出你所有apps的vmcapps，提交一个apps等等。这类request会被路由到AppLife Management组件，又叫CloudController组件去；第二类是外界对你所部署的apps访问的request。这部份requests会被路由到Appexecution，又或者叫做DEAs的组件去。所有进入CloudFoundry系统的requests都会经过Router组件，看到这里可能会有朋友会担心Router成为单点，从而成为整个云的瓶颈。但是CloudFoundry作为云系统，其设计的核心就是去单点依赖，组件平行扩充，且可替代的以保证扩展性，这是CloudFoundry，甚至所有云计算系统的设计原则，后文会讨论CloudFoundry如何做到这点，目前只要知道，系统可以部署多个Routers共同处理进来的requests，但是Router上层的LoadBalance不在CloudFoundry的实现范围，CloudFoundry只保证所有的request是无状态的，这样就使上层均衡附载选择面非常非常大了，例如可以通过DNS做，也可以部署硬件的LoadBalancer，或者简单点，弄台ngnix作负载均衡器，都是可行的。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">Router组件，目前版本是对nginx的一个简单封装。熟悉ngnix的朋友应该知道，它可以一个套接字文件（.sock文件）作为输入输出。所有安装CloudFoundry的Router组件服务器都会安装一个nginx，其ngnix.conf文件有以下配置：</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><div class="timg" style="margin-top: 0px !important; margin-right: 0px !important; margin-bottom: 0px !important; margin-left: 0px !important; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; display: inline-block; position: relative; height: 87px; width: 610px; "><img class="qImg media" src="http://ww2.sinaimg.cn/mw600/88ca09aajw1dmgbh0xa3fj.jpg" style="margin-top: 6px; margin-right: 1px; margin-bottom: 10px; margin-left: 1px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 5px; border-right-width: 5px; border-bottom-width: 5px; border-left-width: 5px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; display: block; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-color: rgb(225, 225, 218); border-right-color: rgb(225, 225, 218); border-bottom-color: rgb(225, 225, 218); border-left-color: rgb(225, 225, 218); max-width: 600px; "></div><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">从整体的来看，Router组件的结构如下：</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><div class="timg" style="margin-top: 0px !important; margin-right: 0px !important; margin-bottom: 0px !important; margin-left: 0px !important; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; display: inline-block; position: relative; height: 453px; width: 361px; "><img class="qImg media" src="http://ww2.sinaimg.cn/mw600/88ca09aajw1dmgbqbvur5j.jpg" style="margin-top: 6px; margin-right: 1px; margin-bottom: 10px; margin-left: 1px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 5px; border-right-width: 5px; border-bottom-width: 5px; border-left-width: 5px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; display: block; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-color: rgb(225, 225, 218); border-right-color: rgb(225, 225, 218); border-bottom-color: rgb(225, 225, 218); border-left-color: rgb(225, 225, 218); max-width: 600px; "></div><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">外界httprequest进入CloudFoundry服务器，nginx会首先接到request，nginx通过sock与router.rb进行交互，于是真正处理请求的是Router组件。router.rb里面根据传入的url，用户名密码等，进行逻辑判断，到CloudController组件或者DEA组件取数据并且返通过与niginx连接的.sock文件返回。router.rb是对nginx进行了逻辑封装。熟悉CloudFoundry的朋友肯定知道，CloudFoundry给每一个app分配了一个url访问，如果直接使用VMware所托管的CloudFoundry.com的话，那你的app的url可能就是xxx.cloudfoundry.com，无论通过命令给你的app扩展了多少个instances，都是从这个url访问的，这里面的url转换路由就是由router.rb实现的。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">2、&nbsp; DEA(Droplet Execution Agency): 首先要解析下什么叫做Droplet。Droplet在CloudFoundry的概念里面是指一个把你提交的源代码，以及CloudFoundry配套好的运行环境，再加上一些管理脚本，例如Start/Stop这些小脚本全部压缩好在一起的tar包。还有一个概念，叫做Stagingapp，就是指制作上面描述这个包，然后把它存储好的过程。CloudFoundry会自动保存这个Droplet，直到你start一个app的时候，一台部署了DEA模块的服务器会来拿一个Droplet的copy去运行。所以如果你扩展你的app到10个instances，那这个Droplet就被会复制十份，让10个DEA服务器拿去运行。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">下图是DEA模块的架构图：</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><div class="timg" style="margin-top: 0px !important; margin-right: 0px !important; margin-bottom: 0px !important; margin-left: 0px !important; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; display: inline-block; position: relative; height: 328px; width: 464px; "><img class="qImg media" src="http://ww1.sinaimg.cn/mw600/88ca09aajw1dmgbr2nq1vj.jpg" style="margin-top: 6px; margin-right: 1px; margin-bottom: 10px; margin-left: 1px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 5px; border-right-width: 5px; border-bottom-width: 5px; border-left-width: 5px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; display: block; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-color: rgb(225, 225, 218); border-right-color: rgb(225, 225, 218); border-bottom-color: rgb(225, 225, 218); border-left-color: rgb(225, 225, 218); max-width: 600px; "></div><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">Cloud Controller模块（下面会介绍）会发送start/stop等基本的apps管理请求给DEA，dea.rb接收这些请求，然后从NFS里面找到合适的Droplet。前面说到Droplet其实是一个带有运行脚本的，带运行环境的tar包，DEA只需要把它拿过来解压，并即行里面的start脚本，就可以让这个app跑起来。到此，app算是可以访问，并start起来了，换句话说就是有这台服务器的某一个端口已经在待命，只要有request从这个端口进来，这个app就可以接收并返回正确的信息。接着dea.rb要做些善后的工作：1、把这个信息告诉Router模块。我们前面说到，所有进入CloudFoundry的requests都是由Router模块处理并转发的，包括用户对app的访问request，一个app起来后，需要告诉router，让它根据loadbalance等原则，把合适的request转进来，使这个app的instance能够干起活；2、一些统计性的工作，例如要把这个用户又新部署了一个app告诉CloudController，以作quota控制等；3、把运行信息告诉HealthManager模块，实时报告该app的instance运行情况。另外DEA还要负责部份对Droplet的查询工作，譬如，如果用户通过CloudController想查询一个app的log信息，那DEA需要从该Droplet里面取到log返回等等。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">3、CloudController：CloudController是CloudFoundry的管理模块。主要工作包括：</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">a) 对apps的增删改读；</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">b) 启动、停止应用程序；</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">c) Staging apps（把apps打包成一个droplet）；</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">d) 修改应用程序运行环境，包括instance、mem等等；</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">e) 管理service，包括service与app的绑定等；</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">f) Cloud环境的管理；</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">g) 修改Cloud的用户信息；</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">h) 查看Cloud Foundry，以及每一个app的log信息。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">这似乎有点复杂，但简单的说，可以很简单：就是与VMC和STS交互的服务器端。VMC和STS与CloudFoundry通信采用的是restful接口，另一方面CloudController是一个典型的Rubyon Rails项目，从VMC或者STS接到JSON格式的协议，然后写入CloudController Database，并发消息到各模快去控制管理整个云。和其他ROR项目一样，CloudController的所有API可以从conf/routes.rb里看到。开放的Restful接口好处在于第三方应用开发和集成，企业在用CloudFoundry部署私有云的时候，可以通过这些接口来自动化控制管理整个Cloud环境。这部份内容将在第二部份论述。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">下图是Cloud Controller的架构图：</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><div class="timg" style="margin-top: 0px !important; margin-right: 0px !important; margin-bottom: 0px !important; margin-left: 0px !important; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; display: inline-block; position: relative; height: 334px; width: 373px; "><img class="qImg media" src="http://ww3.sinaimg.cn/mw600/88ca09aajw1dmgbucgyz2j.jpg" style="margin-top: 6px; margin-right: 1px; margin-bottom: 10px; margin-left: 1px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 5px; border-right-width: 5px; border-bottom-width: 5px; border-left-width: 5px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; display: block; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-color: rgb(225, 225, 218); border-right-color: rgb(225, 225, 218); border-bottom-color: rgb(225, 225, 218); border-left-color: rgb(225, 225, 218); max-width: 600px; "></div><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">图中Health Manager和DEA是外部模块，CCDatabase就是CloudController Database，这个是整个CloudFoundry不能做HP的地方。CloudController Database的并发性不会很多，应用级别的数据库访问是由底下的Service模块处理的，这个数据库存的是Cloud的配置信息。读操作主要来自DEA启动，作为初始化DEA的依据；以及healthmanager模块会从这里读取预期的状态信息，这部份数据会与从DEA得到的实际状态信息进行比对。NFS是多个CloudController的共享存储，CloudController其中一个重要工作就是StagingApps。Droplets的存储是在集群环境的唯一的。而CloudController是集群运行，换言之，就是每一个控制Request可能由不同的CloudController处理，假设一个简单的用户场景：我们需要部署一个app到CloudFoundry中。我们在敲完那条简单的push命令后，VMC开始工作，在做完一轮的用户鉴权、查看所部署的apps数量是否超过预定数额，问了一堆相关app的问题后，需要发4个指令：</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">1．发一个POST到”apps”，创建一个app;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">2．发一个PUT到”apps/:name/application”，上传app;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">3．发一个GET到”apps/:name/”，取得app状态，看看是否已经启动；</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">4．如果没有启动，发一个PUT到”apps/:name/”，使其启动。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">如果第2和第4步由不同的Cloud Controller来处理，而又无法保证他们能找到同一个Droplet，那第4步将会因为找不到对应的Droplet而启动失败。如何保证这一连串指令过来所指向的Droplet都是同一个呢？使用NFS，使CloudController共享存储是最简单的方法。但是这个方法在安全性等方面并不完美。在10月12日的VMwareCloud Forum上，Pat告诉我们下一版本的CloudFoundry这里将会有大调整，但是在那部份代码公开前，我不方便在这评价太多。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">4、&nbsp; HealthManager: 做的事情不复杂，简单的说是从各个DEA里面拿到运行信息，然后进行统计分析，报告等。统计数据会与CloudController的设定指标进行比对，并提供Alert等。HealthManager模块目前还不是十分完善，但是CloudManage栈里面，自动化health管理、分析是一个很重要的领域，而这方面可以扩展的地方也很多，结合OrchestrationEngine可以使云自管理、自预警；而与BI方面技术结合，可以统计运营情况，合理分配资源等。这方面CloudFoundry还在发展之中。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">5、&nbsp; Services:Cloud Foundry的Service模块从源代码控制上看就知道是一个独立的、可Plugin的模块，以方便第三方把自己的服务整合入CloudFoundry生态系统。在Github上看到service是与CloudFoundry Core项目vcap独立的一个repository，为vcap-service。Service模块其中设计原则是方便第三方服务提供商提供服务。在这方面CloudFoundry做得很成功，从Github上看，已经有以下服务提供：a)MongoDB; b) mysql; c) neo4j; d) PostgreSql; e) RabbitMQ; f) Redis; g)vBlob。基类都是放在base文件夹中。 第三方如果需要自己开发CloudFoundry的服务，需要继承改写它里面的两个基础类：Node和Gateway；而里面一些操作，如：Provision，可以在base的provisioner.rb基础上加入自己的逻辑，同样的还有Service_Error和Service_Message等。关于如何写自己的Service，ELC的博客会推出相应文章详细论述，并不在本文的讨论范围里面，从架构了解上来说，只要知道服务间的关系，知道个服务与base间透过继承关系来横向扩充，而CloudFoundry与apps调用Service是通过base来完成这一简单的架构方法即可。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">6、&nbsp; NATS(Message bus): 从CloudFoundry的总架构图看，位于各模块中心位置的是一个叫nats的组件。NATS是由CloudFoundry的架构师Derek开发的一个轻量级的，支持发布、订阅机制的消息系统。Github开源地址是：https://github.com/derekcollison/nats。其核心基于EventMachine开发，代码量不多，可以下载下来慢慢研究。CloudFoundry是一个多模块的分布式系统，支持模块自发现，错误自检，且模块间低耦合。其核心原理就是基于消息发布订阅机制。每个台服务器上的每个模块会根据自己的消息类别，向MessageBus发布多个消息主题；而同时也向自己需要交互的模块，按照需要的信息内容的消息主题订阅消息。譬如：一个DEA被加入CloudFoundry集群中，它需要向大家吼一下，以表明它已经准备好服务了，它会发布一个主题是”dea.start”的消息：</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><div class="timg" style="margin-top: 0px !important; margin-right: 0px !important; margin-bottom: 0px !important; margin-left: 0px !important; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; display: inline-block; position: relative; height: 42px; width: 610px; "><img class="qImg media" src="http://ww3.sinaimg.cn/mw600/88ca09aajw1dmgc7tbng2j.jpg" style="margin-top: 6px; margin-right: 1px; margin-bottom: 10px; margin-left: 1px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 5px; border-right-width: 5px; border-bottom-width: 5px; border-left-width: 5px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; display: block; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-color: rgb(225, 225, 218); border-right-color: rgb(225, 225, 218); border-bottom-color: rgb(225, 225, 218); border-left-color: rgb(225, 225, 218); max-width: 600px; "></div><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">@ hello_message_json中包括DEA的UUID,ip, port, 版本信息等内容。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">再例如，CloudController需要启动一个Droplet的instance：</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">a) &nbsp;首先一个DEA在启动的时候，会首先会对自己UUID的消息主题进行订阅。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><div class="timg" style="margin-top: 0px !important; margin-right: 0px !important; margin-bottom: 0px !important; margin-left: 0px !important; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; display: inline-block; position: relative; height: 42px; width: 610px; "><img class="qImg media" src="http://ww1.sinaimg.cn/mw600/88ca09aajw1dmgc990xa1j.jpg" style="margin-top: 6px; margin-right: 1px; margin-bottom: 10px; margin-left: 1px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 5px; border-right-width: 5px; border-bottom-width: 5px; border-left-width: 5px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; display: block; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-color: rgb(225, 225, 218); border-right-color: rgb(225, 225, 218); border-bottom-color: rgb(225, 225, 218); border-left-color: rgb(225, 225, 218); max-width: 600px; "></div>&nbsp;&nbsp;<p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">其他模块需要通过’’dea.#{uuid}.start”这个主题发送消息来使它启动，一旦这个DEA接收到消息，就会触发process_dea_start(msg)这个方法来处理启动所需要的工作。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">b) &nbsp;Cloud Controller或者其他模块发送消息，让UUID为xxx的DEA启动。</p><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; "><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><div class="timg" style="margin-top: 0px !important; margin-right: 0px !important; margin-bottom: 0px !important; margin-left: 0px !important; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; display: inline-block; position: relative; height: 41px; width: 610px; "><img class="qImg media" src="http://ww2.sinaimg.cn/mw600/88ca09aajw1dmgc9x3v6oj.jpg" style="margin-top: 6px; margin-right: 1px; margin-bottom: 10px; margin-left: 1px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 5px; border-right-width: 5px; border-bottom-width: 5px; border-left-width: 5px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; display: block; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-color: rgb(225, 225, 218); border-right-color: rgb(225, 225, 218); border-bottom-color: rgb(225, 225, 218); border-left-color: rgb(225, 225, 218); max-width: 600px; "></div><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">c)&nbsp;&nbsp;DEA模块接收到消息后，就会触发process_dea_start(msg)方法。msg是由其他模块发送过来的消息内容，包括：droplet_id,instance_index, service, runtime等内容，process_dea_start会取得这些启动DEA必须的信息，然后进行一系列操作，例如从NFS中取得Droplet，解压，修改必要环境配置，运行启动脚本等等。等一切都准备好后，然后需要给Router发个消息，告诉它这个Droplet已经随时准备好报效国家，以后有相应的request记得让它来处理。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><div class="timg" style="margin-top: 0px !important; margin-right: 0px !important; margin-bottom: 0px !important; margin-left: 0px !important; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; display: inline-block; position: relative; height: 183px; width: 610px; "><img class="qImg media" src="http://ww2.sinaimg.cn/mw600/88ca09aajw1dmgcessdizj.jpg" style="margin-top: 6px; margin-right: 1px; margin-bottom: 10px; margin-left: 1px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 5px; border-right-width: 5px; border-bottom-width: 5px; border-left-width: 5px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; display: block; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-color: rgb(225, 225, 218); border-right-color: rgb(225, 225, 218); border-bottom-color: rgb(225, 225, 218); border-left-color: rgb(225, 225, 218); max-width: 600px; "></div><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">d) &nbsp;Router模块在启动时就已经订阅”router.register”消息主题。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><div class="timg" style="margin-top: 0px !important; margin-right: 0px !important; margin-bottom: 0px !important; margin-left: 0px !important; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; display: inline-block; position: relative; height: 159px; width: 610px; "><img class="qImg media" src="http://ww1.sinaimg.cn/mw600/88ca09aajw1dmgcfbftntj.jpg" style="margin-top: 6px; margin-right: 1px; margin-bottom: 10px; margin-left: 1px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 5px; border-right-width: 5px; border-bottom-width: 5px; border-left-width: 5px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; display: block; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-color: rgb(225, 225, 218); border-right-color: rgb(225, 225, 218); border-bottom-color: rgb(225, 225, 218); border-left-color: rgb(225, 225, 218); max-width: 600px; "></div><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">收到前面DEA发出的信息后，会触发register_droplet方法，去绑定Droplet。到此启动一个Droplet的instance工作完成。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">我们可以看到整个CloudFoundry的核心就是一套消息系统，如果想了解CloudFoundry的来龙去脉，去跟踪它里面复杂的消息机制是非常好的方法。另一方面，CloudFoundry是一套基于消息的分布式系统，面向消息的架构是它节点横向扩展，组件自发现等云特性的基础。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">Cloud Foundry的架构简单介绍至此，其实作为第一款开源的PaaS，CloudFoundry架构有很多可以学习借鉴的地方，很多细节上的处理是很精妙的，这些内容如果有可能会在后续文章继续探讨，本文题虽为深入CloudFoundry，其实也只是浅尝即止，把总体架构介绍一下，目标在于使我们有足够的背景知识去用CloudFoundry搭建企业内部的私有PaaS。总结一下，笔者从CloudFoundry的结构中学到的东西：</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">1、&nbsp; 基于消息的多组件架构是实现集群的简单、且有效方法。消息可以使集群节点间解耦，使自注册，自发现这些在大规模数据中心中很重要的功能得到实现；</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">2、&nbsp; 适当的抽象层，模板模式的使用，方便第三方可以方便在CloudFoundry开发扩展功能。CloudFoundry在DEA及Service层都做了抽象层处理，相对应地使开发者可以容易地为CloudFoundry开发Runtime和Service。例如，在CloudFoundry刚推出的时候，只支持Node.js,Java, Ruby，但第三方提供商、开源社区快速跟进，为CloudFoundry添加了PHP,Python的支持。这得益于CloudFoundry精巧的DEA架构设计，如何开发新的Runtime支持，会在后续博文中有所论述.</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><br></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><strong style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: bold; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; ">二、源码导读</strong></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; "><strong style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: bold; font-style: inherit; font-size: 14px; font-family: inherit; vertical-align: baseline; "><br></strong></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">笔者一直觉得深入理解一个技术的最好方法就是读它的源码，而CloudFoundry是完全开源的PaaS平台，而因为刚发展起来，代码量不多，主要作者们的代码功力也相当不错，读起来很舒服，很适合研读。而不得不再次表扬一下它完全基于消息机制的架构设计，对组件扩展性，第三方接入等方面做得很好，读者可以从中学到不少思想性的东西。笔者很推荐大家去读一下它的源代码。你可以在Github上找到CloudFoundry的全部代码：https://github.com/cloudfoundry，你会看到几个不同的Repositories，它们分别是：</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">1、vcap: Cloud Foundry的Core，又或者称作Kernel；</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">2、vcap-service: Cloud Foundry的Service组件。Cloud Foundry的service是作为插件提供的，这出于它方便第三方开发service而设计的；</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">3、vmc: VMware Cloud CLI. 是一个Ruby应用，与Cloud Foundry的CLI交互。主要通过分析用户输入的CLI，向CloudFoundry发送Restful请求；</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">4、vcap-java: 如果你的app是用java开发，且需要与Cloud Foundry交互，例如取得当前serviceserver的ip地址等，你可能需要这个jar，里面对我们Java开发常用框架有所支持，它底层也是对CloudFoundry的Restful请求的包装；</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">5、vcap-java-client: Cloud Foundry的Restful API的Java封装，与上面的项目不一样，它只是个简单的读取CloudFoundry信息，并放如JavaBean中；</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">6、vcap-test: Cloud Foundry的test cases;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">7、vcap-test-assets: Cloud Foundry一些apps示例。</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">&nbsp;</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; outline-width: 0px; outline-style: initial; outline-color: initial; font-weight: inherit; font-style: normal; font-size: 14px; font-family: inherit; vertical-align: baseline; border-style: initial; border-color: initial; text-align: left; word-wrap: break-word; word-break: break-all; ">（未完待续…）</p></div></div></span>