Kubernetes之（六）资源清单定义

常用资源

服务发现及均衡

Sevice,Ingress,...

配置与存储

Volume,CSI,ConfigMap,Secret,DownwardAPI

集群级资源

Namespace,Node,Role,ClusterRole,RoleBinding,ClusterRoleBinding

元数据型资源

HPA,PodTemplate,LimitRange

Kubernetes不只是使用命令行进行配置，常用使用yaml文件来创建配置清单

Pod的资源清单

apiserver仅接收JSON格式的资源定义；

当我们使用kubectl run直接创建资源的时候会被自动转换为JSON格式传给apiserver；

使用yaml格式提供配置清单，apiserver可自动将其转换为JSON格式，然后再提交

root@master ~ apiVersion: v1 kind: Pod metadata: creationTimestamp: generateName: myapp-9b4987d5- labels: pod-template-hash: 9b4987d5 run: myapp name: myapp-9b4987d5-djdr9 namespace: default ownerReferences: - apiVersion: apps/v1 blockOwnerDeletion: controller: kind: ReplicaSet name: myapp-9b4987d5 uid: bc03afbd-5120-11e9-80a7-000c295ec349 resourceVersion: selfLink: /api/v1/namespaces/default/pods/myapp-9b4987d5-djdr9 uid: 995067e0-5124-11e9-80a7-000c295ec349 spec: containers: - image: ikubernetes/myapp:v1 imagePullPolicy: IfNotPresent name: myapp resources: terminationMessagePath: /dev/termination-log terminationMessagePolicy: File volumeMounts: - mountPath: /var/run/secrets/kubernetes.io/serviceaccount name: default-token-dqd2f readOnly: dnsPolicy: ClusterFirst enableServiceLinks: nodeName: node02 priority: restartPolicy: Always schedulerName: default-scheduler securityContext: serviceAccount: default serviceAccountName: default terminationGracePeriodSeconds: tolerations: - effect: NoExecute key: node.kubernetes.io/not-ready operator: Exists tolerationSeconds: - effect: NoExecute key: node.kubernetes.io/unreachable operator: Exists tolerationSeconds: volumes: - name: default-token-dqd2f secret: defaultMode: secretName: default-token-dqd2f status: conditions: - lastProbeTime: null lastTransitionTime: status: type: Initialized - lastProbeTime: null lastTransitionTime: status: type: Ready - lastProbeTime: null lastTransitionTime: status: type: ContainersReady - lastProbeTime: null lastTransitionTime: status: type: PodScheduled containerStatuses: - containerID: docker://69b4cab1eb139c8e9c23e79792782db739fae21bedbc9199e1ab75b10729b038 image: ikubernetes/myapp:v1 imageID: docker-pullable://ikubernetes/myapp@sha256:9c3dc30b5219788b2b8a4b065f548b922a34479577befb54b03330999d30d513 lastState: name: myapp ready: restartCount: state: running: startedAt: hostIP: .0.12 phase: Running podIP: .2.13 qosClass: BestEffort startTime:

大部分资源清单有以下五个字段组成：

apiVersion: group/version # 指明api资源所属的群组及版本,使用kubectl api-version可查看，同一组子资源可以有多个版本

kind: 资源类别，Pod,ReplicaSet,Deployment,StatefulSet,DaemonSet,Job,Cronjob 。注意大小写

metadata： 元数据

name：同一类别要求名字唯一

namespace：对应的对象属于哪个名称空间，默认default

labels：标签，搜友资源都可以有标签，K/V类型

annotations：资源注解

每个资源的引用PATH

/api/GROUP/VERSION/namespaces/NAMESPACE/TYPE/NAME

小写是固定字符，大写是根据实际情况修改

**spec:**最重要字段，定义目标的期望状态，desired state，不同类型资源内部可能有所不同

**status:**当前状态（只读）本字段由kubernetes进行维护

以上可以使用kubectl explain 进行查看相应字段

root@master ~ KIND: Pod VERSION: v1 DESCRIPTION: Pod is a collection of containers that can run on a host. This resource is created by clients and scheduled onto hosts. FIELDS: apiVersion string APIVersion defines the versioned schema of this representation of an object. Servers should convert recognized schemas to the latest internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/api-conventions.md kind string Kind is a string value representing the REST resource this object represents. Servers may infer this from the endpoint the client submits requests to. Cannot be updated. In CamelCase. More info: https://git.k8s.io/community/contributors/devel/api-conventions.md metadata Object Standard object's metadata. More info: https://git.k8s.io/community/contributors/devel/api-conventions.md spec Object Specification of the desired behavior of the pod. More info: https://git.k8s.io/community/contributors/devel/api-conventions.md status Object Most recently observed status of the pod. This data may not be up to date. Populated by the system. Read-only. More info: https://git.k8s.io/community/contributors/devel/api-conventions.md

查看下一集字段，例如pods下的metadata，使用kubectl explain pods.metadata,以此类推.

二级字段下，每一种字段都有对应的键值类型，常用类型大致如下：

<[ ]string>：表示是一个字串列表，也就是字串类型的数组

<Object>：表示是可以嵌套的字段

<map[string]string>：表示是一个由键值组成映射

<[ ]Object>：表示是一个对象列表

<[ ]Object> -required-：required表示该字段是一个必选的字段

利用配置清单定义自主式Pod资源

root@master ~ root@master ~ root@master manifests labels: apiVersion: v1 kind: Pod metadata: name: pod-demo namespace: default labels: app: myapp tier: frontend spec: containers: - name: myapp image: ikubernetes/myapp:v1 - name: busybox image: busybox command: - - -

使用**kubectl create -f **.yaml**创建资源

root@master manifests pod/pod-demo created root@master manifests Name: pod-demo Namespace: default Priority: PriorityClassName: none Node: node02/10.0.0.12 Start Time: Thu, Mar :27:35 +0800 Labels: myapp frontend Annotations: none Status: Running IP: .2.15 Containers: myapp: Container ID: docker://81fcdf25bac4f9691aaa80ccf1acd0fe565575ea894d07ea1c382e0366bcbfba Image: ikubernetes/myapp:v1 Image ID: docker-pullable://ikubernetes/myapp@sha256:9c3dc30b5219788b2b8a4b065f548b922a34479577befb54b03330999d30d513 Port: none Host Port: none State: Running Started: Thu, Mar :27:35 +0800 Ready: True Restart Count: Environment: none Mounts: /var/run/secrets/kubernetes.io/serviceaccount from default-token-dqd2f ro busybox: Container ID: docker://af0d0f76b0f6ba9eeaea18178d1d9cf3a052176e219471896a56d727622c9a36 Image: busybox Image ID: docker-pullable://busybox@sha256:061ca9704a714ee3e8b80523ec720c64f6209ad3f97c0ff7cb9ec7d19f15149f Port: none Host Port: none Command: /bin/sh -c State: Running Started: Thu, Mar :27:37 +0800 Ready: True Restart Count: Environment: none Mounts: /var/run/secrets/kubernetes.io/serviceaccount from default-token-dqd2f ro Conditions: Type Status Initialized True Ready True ContainersReady True PodScheduled True Volumes: default-token-dqd2f: Type: Secret a volume populated by a Secret SecretName: default-token-dqd2f Optional: QoS Class: BestEffort Node-Selectors: none Tolerations: node.kubernetes.io/not-ready:NoExecute 300s node.kubernetes.io/unreachable:NoExecute 300s Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal Scheduled 13s default-scheduler Successfully assigned default/pod-demo to node02 Normal Pulled 13s kubelet, node02 Container image already present on machine Normal Created 13s kubelet, node02 Created container Normal Started 13s kubelet, node02 Started container Normal Pulling 13s kubelet, node02 pulling image Normal Pulled 11s kubelet, node02 Successfully pulled image Normal Created 11s kubelet, node02 Created container Normal Started 11s kubelet, node02 Started container

使用kubectl delete -f .yaml删除资源

使用kubectl logs POD_NAME -c CONTAINER_NAME 查看指定Pod内的指定容器的日志

使用kubectl exec -it POD_NAME-c CONTAINER_NAME -- /bin/sh ** 交互式进入指定Pod内的指定容器内部

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