Kubernetes（k8s）Pod的YAML基础编写

Kubernetes中的Pod一般都是采用yaml编写

apiVersion: group/apiversion  # 如果没有给定 group 名称，那么默认为 core，可以使用 kubectl api-versions # 获取当前 k8s 版本上所有的 apiVersion 版本信息( 每个版本可能不同 )
kind:       #资源类别
metadata：  #资源元数据
   name
   namespace
   lables
   annotations   # 主要目的是方便用户阅读查找
spec: # 期望的状态（disired state）
status：# 当前状态，本字段有 Kubernetes 自身维护，用户不能去定义

资源清单的常用命令

获取 apiversion 版本信息

1.apiVersion

kubectl api-versions: 显示所有支持的群组

[root@master1 ~]# kubectl api-versions
admissionregistration.k8s.io/v1
admissionregistration.k8s.io/v1beta1
apiextensions.k8s.io/v1
apiextensions.k8s.io/v1beta1
apiregistration.k8s.io/v1
apiregistration.k8s.io/v1beta1
apps/v1
authentication.k8s.io/v1
authentication.k8s.io/v1beta1
authorization.k8s.io/v1
authorization.k8s.io/v1beta1
autoscaling/v1
autoscaling/v2beta1
autoscaling/v2beta2
batch/v1
batch/v1beta1
certificates.k8s.io/v1beta1
coordination.k8s.io/v1
coordination.k8s.io/v1beta1
discovery.k8s.io/v1beta1
events.k8s.io/v1beta1
extensions/v1beta1
networking.k8s.io/v1
networking.k8s.io/v1beta1
node.k8s.io/v1beta1
policy/v1beta1
rbac.authorization.k8s.io/v1
rbac.authorization.k8s.io/v1beta1
scheduling.k8s.io/v1
scheduling.k8s.io/v1beta1
storage.k8s.io/v1
storage.k8s.io/v1beta1
v1  # 核心群组

2.kind

常用资源类别：workload, Pod, ReplicaSet, Deployment, StatefulSet, DaemonSet, Job, Cronjob等。

查看所有资源api-resources

[root@master1 ~]# kubectl api-resources
NAME                              SHORTNAMES   APIGROUP                       NAMESPACED   KIND
bindings                                                                      true         Binding
componentstatuses                 cs                                          false        ComponentStatus
configmaps                        cm                                          true         ConfigMap
endpoints                         ep                                          true         Endpoints
events                            ev                                          true         Event
limitranges                       limits                                      true         LimitRange
namespaces                        ns                                          false        Namespace
nodes                             no                                          false        Node
persistentvolumeclaims            pvc                                         true         PersistentVolumeClaim
persistentvolumes                 pv                                          false        PersistentVolume
pods                              po                                          true         Pod
podtemplates                                                                  true         PodTemplate
replicationcontrollers            rc                                          true         ReplicationController
resourcequotas                    quota                                       true         ResourceQuota
secrets                                                                       true         Secret
serviceaccounts                   sa                                          true         ServiceAccount
services                          svc                                         true         Service
mutatingwebhookconfigurations                  admissionregistration.k8s.io   false        MutatingWebhookConfiguration
validatingwebhookconfigurations                admissionregistration.k8s.io   false        ValidatingWebhookConfiguration
customresourcedefinitions         crd,crds     apiextensions.k8s.io           false        CustomResourceDefinition
apiservices                                    apiregistration.k8s.io         false        APIService
controllerrevisions                            apps                           true         ControllerRevision
daemonsets                        ds           apps                           true         DaemonSet
deployments                       deploy       apps                           true         Deployment
replicasets                       rs           apps                           true         ReplicaSet
statefulsets                      sts          apps                           true         StatefulSet
tokenreviews                                   authentication.k8s.io          false        TokenReview
localsubjectaccessreviews                      authorization.k8s.io           true         LocalSubjectAccessReview
selfsubjectaccessreviews                       authorization.k8s.io           false        SelfSubjectAccessReview
selfsubjectrulesreviews                        authorization.k8s.io           false        SelfSubjectRulesReview
subjectaccessreviews                           authorization.k8s.io           false        SubjectAccessReview
horizontalpodautoscalers          hpa          autoscaling                    true         HorizontalPodAutoscaler
cronjobs                          cj           batch                          true         CronJob
jobs                                           batch                          true         Job
certificatesigningrequests        csr          certificates.k8s.io            false        CertificateSigningRequest
leases                                         coordination.k8s.io            true         Lease
endpointslices                                 discovery.k8s.io               true         EndpointSlice
events                            ev           events.k8s.io                  true         Event
ingresses                         ing          extensions                     true         Ingress
ingressclasses                                 networking.k8s.io              false        IngressClass
ingresses                         ing          networking.k8s.io              true         Ingress
networkpolicies                   netpol       networking.k8s.io              true         NetworkPolicy
runtimeclasses                                 node.k8s.io                    false        RuntimeClass
poddisruptionbudgets              pdb          policy                         true         PodDisruptionBudget
podsecuritypolicies               psp          policy                         false        PodSecurityPolicy
clusterrolebindings                            rbac.authorization.k8s.io      false        ClusterRoleBinding
clusterroles                                   rbac.authorization.k8s.io      false        ClusterRole
rolebindings                                   rbac.authorization.k8s.io      true         RoleBinding
roles                                          rbac.authorization.k8s.io      true         Role
priorityclasses                   pc           scheduling.k8s.io              false        PriorityClass
csidrivers                                     storage.k8s.io                 false        CSIDriver
csinodes                                       storage.k8s.io                 false        CSINode
storageclasses                    sc           storage.k8s.io                 false        StorageClass
volumeattachments                              storage.k8s.io                 false        VolumeAttachment

3.metadata

• name: 名称
• namespace: 名称空间
• labels: 资源标签
• annotations:
• 每个资源可以通过路径PATH被引用：/aip/GROUP/NAME/namespaces/NAMESPACE/TYPE/NAME

4.spec

• disired定义用户期望的状态信息
• status: 当前状态，current state, 本字段由kubernetes集群维护

重要：kubectl explain <object>: 查看官方object资源对象定义介绍，通过在此命令后面添加”.<object>“可以查看二级和三级等子对象的使用说明。

5.status

由系统自动生成，只读形式显示最近状态。

获取字段设置帮助文档

[root@k8s-master01 ~]# kubectl explain pod
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>
     ........
     ........

字段配置格式

apiVersion <string>          #表示字符串类型
metadata <Object>            #表示需要嵌套多层字段
labels <map[string]string>   #表示由k:v组成的映射
finalizers <[]string>        #表示字串列表
ownerReferences <[]Object>   #表示对象列表
hostPID <boolean>            #布尔类型
priority <integer>           #整型
name <string> -required-     #如果类型后面接 -required-，表示为必填字段

通过定义清单文件创建 Pod【myapp这个是nginx镜像】（这地方有个错误哦，下面讲）

apiVersion: v1
kind: Pod
metadata:
  name: myapp-pod
  labels:
    app: myapp
    version: v1
spec:
  containers:
  - name: app
    image: wangyanglinux/myapp:v1
  - name: test
    image: wangyanglinux/myapp:v1

错误：因为这回事nginx容器，在同一Pod中，只用一个80端口可以，所以，一个会一直报错。看下面截图

【一个在运行，一个在一直报错重启。】

运行Pod.yaml文件

kubectl apply -f pod.yaml