​Kubernetes资源清单篇：如何创建资源？​

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在Kubernetes中所有操作的内容，我们都称为“资源对象”，是由API Server基于HTTP/HTTPS接收并响应客户端的操作请求，是一种Restful风格的接口，将各种组件及操作内容都抽象成为标准的REST资源，如Namespace、Pod等，其中操作内容以JSON或yml格式数据进行操作。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"本文讲解的是Kubernetes中的最为重要的一节——","attrs":{}},{"type":"text","marks":[{"type":"strong","attrs":{}}],"text":"资源清单","attrs":{}},{"type":"text","text":"，我们想要在Kubernetes中部署Pod、Service等资源对象，都需要通过资源清单的方式来部署，无论是通过命令kubectl，还是可视化控制台，都是离不开资源清单的定义，本文重点讲述资源清单如何定义、如何创建及使用。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":1},"content":[{"type":"text","text":"1、资源分类","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"根据资源的功能进行资源分类，Kubernetes资源对象可分为：","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong","attrs":{}}],"text":"工作负载（Workload）","attrs":{}},{"type":"text","text":"：Pod、ReplicaSet、Deployment、StatefulSet、DaemonSet、Job、CronJob。","attrs":{}}]}],"attrs":{}}],"attrs":{}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong","attrs":{}}],"text":"发现和负载均衡（Discovery & LB）","attrs":{}},{"type":"text","text":"：Service 、Ingress。","attrs":{}}]}],"attrs":{}}],"attrs":{}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong","attrs":{}}],"text":"配置和存储（Config & Storage）","attrs":{}},{"type":"text","text":"： Volume（存储卷）、CSI（容器存储接口，可以扩展各种各样的第三方存储卷）。","attrs":{}}]}],"attrs":{}}],"attrs":{}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong","attrs":{}}],"text":"集群（Cluster）","attrs":{}},{"type":"text","text":"：Namespace、Node、Role、ClusterRole、RoleBinding（角色绑定）、ClusterRoleBinding（集群角色绑定）。","attrs":{}}]}],"attrs":{}}],"attrs":{}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong","attrs":{}}],"text":"元数据（Metadata）","attrs":{}},{"type":"text","text":"：HPA、PodTemplate（Pod模板，用于让控制器创建Pod时使用的模板）、LimitRange（用来定义硬件资源限制的）。","attrs":{}}]}],"attrs":{}}],"attrs":{}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"一个应用通常需要多个资源的支撑，例如，使用Deployment资源管理应用实例（Pod）、使用ConfigMap资源保存应用配置、使用Service或Ingress资源暴露服务、使用Volume资源提供外部存储等。","attrs":{}}]}],"attrs":{}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":1},"content":[{"type":"text","text":"2.资源清单","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"资源清单，等同于一个剧本，能够告诉我们每一步应该怎么去做，Kubernetes接收到这么一个剧本，就能够按照这个剧本去执行，以达到我们的预期。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在Kubernetes中，一般都是通过定义资源清单的方式去创建资源。一般使用yaml格式的文件来创建符合我们预期期望的资源，这样的yaml文件我们称为","attrs":{}},{"type":"text","marks":[{"type":"strong","attrs":{}}],"text":"资源清单","attrs":{}},{"type":"text","text":"。（也可以定义为json格式）","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"如，创建一个Pod资源：","attrs":{}}]},{"type":"codeblock","attrs":{"lang":"shell"},"content":[{"type":"text","text":"apiVersion: v1\nkind: Pod\nmetadata:\n name: vue-frontend\n namespace: test\n labels:\n app: vue-frontend\nspec:\n containers:\n - name: vue-frontend\n image: xcbeyond/vue-frontend:latest\n ports:\n - name: port\n containerPort: 80\n hostPort: 8080","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"接下来，以Pod资源定义为例展开对资源清单的详细说明。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"2.1 资源清单定义","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"yaml格式的Pod资源清单定义文件的完整内容如下：","attrs":{}}]},{"type":"codeblock","attrs":{"lang":"shell"},"content":[{"type":"text","text":"apiVersion: v1\nkind: Pod\t\t# 资源类别\nmetadata:\t\t# 资源元数据\n name: string\n namespace: string\n labels:\n - name: string\n annotations:\n - name: string\nspec:\t\t\t# 资源期望的状态\n containers:\t\t# 容器列表\n - name: string\t\t# 容器名称，下面的属性均属于对该容器的定义或约束\n image: string\n imagePullPolicy: [Always|Never|IfNotPresent]\n command: [string]\n args: [string]\n workingDir: string\n volumeMounts:\n - name: string\n mountPath: string\n readOnly: boolean\n ports:\n - name: string\n containerPort: int\n hostPort: int\n protocol: string\n env:\n - name: string\n value: string\n resources:\n limits:\n cpu: string\n memory: string\n requests:\n cpu: string\n memory: string\n livenssProbe:\n exec:\n command: [string]\n httpGet:\n path: string\n port: number\n host: string\n scheme: string\n httpHeaders:\n - name: string\n value: string\n tcpSocket:\n port: number\n initialDelaySeconds: 0\n timeoutSeconds: 0\n periodSeconds: 0\n successThreshold: 0\n failureThreshold: 0\n…… ","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"对各属性的详细说明如下表所示：","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"（必选属性，是必须存在的，否则创建失败。）","attrs":{}}]},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/11/114c3a975a28b486bb23290bb6048eb8.jpeg","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/69/69356a89b92eb2579cf60dba80a9d490.jpeg","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/b3/b3d269b74f0cc256eeee4f3d44cf3755.jpeg","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/d8/d8d9fd47865dc5c34ab3a0fecee4b658.jpeg","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"上述列举的是常用的属性，如果想查看全部属性，可以使用命令","attrs":{}},{"type":"codeinline","content":[{"type":"text","text":"kubectl explain pod","attrs":{}}],"attrs":{}},{"type":"text","text":"：","attrs":{}}]},{"type":"codeblock","attrs":{"lang":"shell"},"content":[{"type":"text","text":"[xcbeyond@bogon ~]$ kubectl explain pod\nKIND: Pod\nVERSION: v1\n\nDESCRIPTION:\n Pod is a collection of containers that can run on a host. This resource is\n created by clients and scheduled onto hosts.\n\nFIELDS:\n apiVersion\t\n APIVersion defines the versioned schema of this representation of an\n object. Servers should convert recognized schemas to the latest internal\n value, and may reject unrecognized values. More info:\n https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources\n\n kind\t\n Kind is a string value representing the REST resource this object\n represents. Servers may infer this from the endpoint the client submits\n requests to. Cannot be updated. In CamelCase. More info:\n https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds\n\n metadata\t