# 快速上手 目前，Kubenetes 支持在多种环境下的安装，包括本地主机（Fedora）、云服务（Google GAE、AWS 等）。然而最快速体验 Kubernetes 的方式显然是本地通过 Docker 的方式来启动相关进程。 下图展示了在单节点使用 Docker 快速部署一套 Kubernetes 的拓扑。  Kubernetes 依赖 Etcd 服务来维护所有主节点的状态。 ## 启动 Etcd 服务。 ``` <pre class="prettyprint"><ol class="linenums"><li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln">docker run </span><span class="pun">--</span><span class="pln">net</span><span class="pun">=</span><span class="pln">host </span><span class="pun">-</span><span class="pln">d gcr</span><span class="pun">.</span><span class="pln">io</span><span class="pun">/</span><span class="pln">google_containers</span><span class="pun">/</span><span class="pln">etcd</span><span class="pun">:</span><span class="lit">2.0</span><span class="pun">.</span><span class="lit">9</span><span class="pln"> </span><span class="pun">/</span><span class="pln">usr</span><span class="pun">/</span><span class="kwd">local</span><span class="pun">/</span><span class="pln">bin</span><span class="pun">/</span><span class="pln">etcd </span><span class="pun">--</span><span class="pln">addr</span><span class="pun">=</span><span class="lit">127.0</span><span class="pun">.</span><span class="lit">0.1</span><span class="pun">:</span><span class="lit">4001</span><span class="pln"> </span><span class="pun">--</span><span class="pln">bind</span><span class="pun">-</span><span class="pln">addr</span><span class="pun">=</span><span class="lit">0.0</span><span class="pun">.</span><span class="lit">0.0</span><span class="pun">:</span><span class="lit">4001</span><span class="pln"> </span><span class="pun">--</span><span class="pln">data</span><span class="pun">-</span><span class="pln">dir</span><span class="pun">=/</span><span class="pln">var</span><span class="pun">/</span><span class="pln">etcd</span><span class="pun">/</span><span class="pln">data</span></code></li></ol> ``` ## 启动主节点 启动 kubelet。 ``` <pre class="prettyprint"><ol class="linenums"><li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln">docker run </span><span class="pun">--</span><span class="pln">net</span><span class="pun">=</span><span class="pln">host </span><span class="pun">-</span><span class="pln">d </span><span class="pun">-</span><span class="pln">v </span><span class="pun">/</span><span class="pln">var</span><span class="pun">/</span><span class="pln">run</span><span class="pun">/</span><span class="pln">docker</span><span class="pun">.</span><span class="pln">sock</span><span class="pun">:/</span><span class="pln">var</span><span class="pun">/</span><span class="pln">run</span><span class="pun">/</span><span class="pln">docker</span><span class="pun">.</span><span class="pln">sock gcr</span><span class="pun">.</span><span class="pln">io</span><span class="pun">/</span><span class="pln">google_containers</span><span class="pun">/</span><span class="pln">hyperkube</span><span class="pun">:</span><span class="pln">v0</span><span class="pun">.</span><span class="lit">17.0</span><span class="pln"> </span><span class="pun">/</span><span class="pln">hyperkube kubelet </span><span class="pun">--</span><span class="pln">api_servers</span><span class="pun">=</span><span class="pln">http</span><span class="pun">://</span><span class="pln">localhost</span><span class="pun">:</span><span class="lit">8080</span><span class="pln"> </span><span class="pun">--</span><span class="pln">v</span><span class="pun">=</span><span class="lit">2</span><span class="pln"> </span><span class="pun">--</span><span class="pln">address</span><span class="pun">=</span><span class="lit">0.0</span><span class="pun">.</span><span class="lit">0.0</span><span class="pln"> </span><span class="pun">--</span><span class="pln">enable_server </span><span class="pun">--</span><span class="pln">hostname_override</span><span class="pun">=</span><span class="lit">127.0</span><span class="pun">.</span><span class="lit">0.1</span><span class="pln"> </span><span class="pun">--</span><span class="pln">config</span><span class="pun">=/</span><span class="pln">etc</span><span class="pun">/</span><span class="pln">kubernetes</span><span class="pun">/</span><span class="pln">manifests</span></code></li></ol> ``` ## 启动服务代理 ``` <pre class="prettyprint"><ol class="linenums"><li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln">docker run </span><span class="pun">-</span><span class="pln">d </span><span class="pun">--</span><span class="pln">net</span><span class="pun">=</span><span class="pln">host </span><span class="pun">--</span><span class="pln">privileged gcr</span><span class="pun">.</span><span class="pln">io</span><span class="pun">/</span><span class="pln">google_containers</span><span class="pun">/</span><span class="pln">hyperkube</span><span class="pun">:</span><span class="pln">v0</span><span class="pun">.</span><span class="lit">17.0</span><span class="pln"> </span><span class="pun">/</span><span class="pln">hyperkube proxy </span><span class="pun">--</span><span class="pln">master</span><span class="pun">=</span><span class="pln">http</span><span class="pun">://</span><span class="lit">127.0</span><span class="pun">.</span><span class="lit">0.1</span><span class="pun">:</span><span class="lit">8080</span><span class="pln"> </span><span class="pun">--</span><span class="pln">v</span><span class="pun">=</span><span class="lit">2</span></code></li></ol> ``` ## 测试状态 在本地访问 `8080` 端口，可以获取到如下的结果： ``` <pre class="prettyprint"><ol class="linenums"><li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln">$ curl </span><span class="lit">127.0</span><span class="pun">.</span><span class="lit">0.1</span><span class="pun">:</span><span class="lit">8080</span></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pun">{</span></code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="str">"paths"</span><span class="pun">:</span><span class="pln"> </span><span class="pun">[</span></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="str">"/api"</span><span class="pun">,</span></code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="str">"/api/v1beta1"</span><span class="pun">,</span></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="str">"/api/v1beta2"</span><span class="pun">,</span></code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="str">"/api/v1beta3"</span><span class="pun">,</span></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="str">"/healthz"</span><span class="pun">,</span></code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="str">"/healthz/ping"</span><span class="pun">,</span></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="str">"/logs/"</span><span class="pun">,</span></code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="str">"/metrics"</span><span class="pun">,</span></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="str">"/static/"</span><span class="pun">,</span></code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="str">"/swagger-ui/"</span><span class="pun">,</span></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="str">"/swaggerapi/"</span><span class="pun">,</span></code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="str">"/validate"</span><span class="pun">,</span></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="str">"/version"</span></code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln"> </span><span class="pun">]</span></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pun">}</span></code></li> </ol> ``` ## 查看服务 所有服务启动后，查看本地实际运行的 Docker 容器，有如下几个。 ``` <pre class="prettyprint"><ol class="linenums"><li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln">CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES</span></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln">ee054db2516c gcr</span><span class="pun">.</span><span class="pln">io</span><span class="pun">/</span><span class="pln">google_containers</span><span class="pun">/</span><span class="pln">hyperkube</span><span class="pun">:</span><span class="pln">v0</span><span class="pun">.</span><span class="lit">17.0</span><span class="pln"> </span><span class="str">"/hyperkube schedule 2 days ago Up 1 days k8s_scheduler.509f29c9_k8s-master-127.0.0.1_default_9941e5170b4365bd4aa91f122ba0c061_e97037f5</span></code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="str">3b0f28de07a2 gcr.io/google_containers/hyperkube:v0.17.0 "</span><span class="pun">/</span><span class="pln">hyperkube apiserve </span><span class="lit">2</span><span class="pln"> days ago </span><span class="typ">Up</span><span class="pln"> </span><span class="lit">1</span><span class="pln"> days k8s_apiserver</span><span class="pun">.</span><span class="lit">245e44fa</span><span class="pln">_k8s</span><span class="pun">-</span><span class="pln">master</span><span class="pun">-</span><span class="lit">127.0</span><span class="pun">.</span><span class="lit">0.1</span><span class="pln">_default_9941e5170b4365bd4aa91f122ba0c061_6ab5c23d</span></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="lit">2eaa44ecdd8e</span><span class="pln"> gcr</span><span class="pun">.</span><span class="pln">io</span><span class="pun">/</span><span class="pln">google_containers</span><span class="pun">/</span><span class="pln">hyperkube</span><span class="pun">:</span><span class="pln">v0</span><span class="pun">.</span><span class="lit">17.0</span><span class="pln"> </span><span class="str">"/hyperkube controll 2 days ago Up 1 days k8s_controller-manager.33f83d43_k8s-master-127.0.0.1_default_9941e5170b4365bd4aa91f122ba0c061_1a60106f</span></code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="str">30aa7163cbef gcr.io/google_containers/hyperkube:v0.17.0 "</span><span class="pun">/</span><span class="pln">hyperkube proxy </span><span class="pun">--</span><span class="pln"> </span><span class="lit">2</span><span class="pln"> days ago </span><span class="typ">Up</span><span class="pln"> </span><span class="lit">1</span><span class="pln"> days jolly_davinci</span></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln">a2f282976d91 gcr</span><span class="pun">.</span><span class="pln">io</span><span class="pun">/</span><span class="pln">google_containers</span><span class="pun">/</span><span class="pln">pause</span><span class="pun">:</span><span class="lit">0.8</span><span class="pun">.</span><span class="lit">0</span><span class="pln"> </span><span class="str">"/pause"</span><span class="pln"> </span><span class="lit">2</span><span class="pln"> days ago </span><span class="typ">Up</span><span class="pln"> </span><span class="lit">2</span><span class="pln"> days k8s_POD</span><span class="pun">.</span><span class="pln">e4cc795_k8s</span><span class="pun">-</span><span class="pln">master</span><span class="pun">-</span><span class="lit">127.0</span><span class="pun">.</span><span class="lit">0.1</span><span class="pln">_default_9941e5170b4365bd4aa91f122ba0c061_e8085b1f</span></code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="pln">c060c52acc36 gcr</span><span class="pun">.</span><span class="pln">io</span><span class="pun">/</span><span class="pln">google_containers</span><span class="pun">/</span><span class="pln">hyperkube</span><span class="pun">:</span><span class="pln">v0</span><span class="pun">.</span><span class="lit">17.0</span><span class="pln"> </span><span class="str">"/hyperkube kubelet 2 days ago Up 1 days serene_nobel</span></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"><span class="str">cc3cd263c581 gcr.io/google_containers/etcd:2.0.9 "</span><span class="pun">/</span><span class="pln">usr</span><span class="pun">/</span><span class="kwd">local</span><span class="pun">/</span><span class="pln">bin</span><span class="pun">/</span><span class="pln">etcd </span><span class="lit">2</span><span class="pln"> days ago </span><span class="typ">Up</span><span class="pln"> </span><span class="lit">1</span><span class="pln"> days happy_turing</span></code></li> </ol> ``` 这些服务大概分为三类：主节点服务、工作节点服务和其它服务。 ### 主节点服务 - `apiserver` 是整个系统的对外接口，提供 RESTful 方式供客户端和其它组件调用； - `scheduler` 负责对资源进行调度，分配某个 pod 到某个节点上； - `controller-manager` 负责管理控制器，包括 endpoint-controller（刷新服务和 pod 的关联信息）和 replication-controller（维护某个 pod 的复制为配置的数值）。 ### 工作节点服务 - `kubelet` 是工作节点执行操作的 agent，负责具体的容器生命周期管理，根据从数据库中获取的信息来管理容器，并上报 pod 运行状态等； - `proxy` 为 pod 上的服务提供访问的代理。 ### 其它服务 - Etcd 是所有状态的存储数据库； - `gcr.io/google_containers/pause:0.8.0` 是 Kubernetes 启动后自动 pull 下来的测试镜像。