​Kubernetes資源清單篇：如何創建資源？​

{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在Kubernetes中所有操作的內容，我們都稱爲“資源對象”，是由API Server基於HTTP/HTTPS接收並響應客戶端的操作請求，是一種Restful風格的接口，將各種組件及操作內容都抽象成爲標準的REST資源，如Namespace、Pod等，其中操作內容以JSON或yml格式數據進行操作。","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":"本文講解的是Kubernetes中的最爲重要的一節——","attrs":{}},{"type":"text","marks":[{"type":"strong","attrs":{}}],"text":"資源清單","attrs":{}},{"type":"text","text":"，我們想要在Kubernetes中部署Pod、Service等資源對象，都需要通過資源清單的方式來部署，無論是通過命令kubectl，還是可視化控制檯，都是離不開資源清單的定義，本文重點講述資源清單如何定義、如何創建及使用。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":1},"content":[{"type":"text","text":"1、資源分類","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":"根據資源的功能進行資源分類，Kubernetes資源對象可分爲：","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":"工作負載（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":"發現和負載均衡（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":"配置和存儲（Config & Storage）","attrs":{}},{"type":"text","text":"： Volume（存儲卷）、CSI（容器存儲接口，可以擴展各種各樣的第三方存儲卷）。","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":"集羣（Cluster）","attrs":{}},{"type":"text","text":"：Namespace、Node、Role、ClusterRole、RoleBinding（角色綁定）、ClusterRoleBinding（集羣角色綁定）。","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":"元數據（Metadata）","attrs":{}},{"type":"text","text":"：HPA、PodTemplate（Pod模板，用於讓控制器創建Pod時使用的模板）、LimitRange（用來定義硬件資源限制的）。","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":"一個應用通常需要多個資源的支撐，例如，使用Deployment資源管理應用實例（Pod）、使用ConfigMap資源保存應用配置、使用Service或Ingress資源暴露服務、使用Volume資源提供外部存儲等。","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.資源清單","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":"資源清單，等同於一個劇本，能夠告訴我們每一步應該怎麼去做，Kubernetes接收到這麼一個劇本，就能夠按照這個劇本去執行，以達到我們的預期。","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，一般都是通過定義資源清單的方式去創建資源。一般使用yaml格式的文件來創建符合我們預期期望的資源，這樣的yaml文件我們稱爲","attrs":{}},{"type":"text","marks":[{"type":"strong","attrs":{}}],"text":"資源清單","attrs":{}},{"type":"text","text":"。（也可以定義爲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，創建一個Pod資源：","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":"接下來，以Pod資源定義爲例展開對資源清單的詳細說明。","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 資源清單定義","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資源清單定義文件的完整內容如下：","attrs":{}}]},{"type":"codeblock","attrs":{"lang":"shell"},"content":[{"type":"text","text":"apiVersion: v1\nkind: Pod\t\t# 資源類別\nmetadata:\t\t# 資源元數據\n name: string\n namespace: string\n labels:\n - name: string\n annotations:\n - name: string\nspec:\t\t\t# 資源期望的狀態\n containers:\t\t# 容器列表\n - name: string\t\t# 容器名稱，下面的屬性均屬於對該容器的定義或約束\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":"對各屬性的詳細說明如下表所示：","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":"（必選屬性，是必須存在的，否則創建失敗。）","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":"上述列舉的是常用的屬性，如果想查看全部屬性，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":"[[email protected] ~]$ 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