k8s源码学习-资源转换器

在Kubernetes系统中，同一资源拥有多个资源版本，Kubernetes系统允许同一资源的不同资源版本进行转换，例如Deployment资源对象，当前运行的是v1beta1资源版本，但v1beta1资源版本的某些功能或字段不如v1资源版本完善，则可以将Deployment资源对象的v1beta1资源版本转换为v1版本。可通过kubectl convert命令进行资源版本转换

kubectl convert 默认没有安装，安装方法参考：​​安装 kubectl convert 插件​​

比如：我定义了一个 v1beta1deploy.yaml

apiVersion: apps/v1beta1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.14.2
        ports:
        - containerPort: 80

创建deployment报错了，我想把它转为v1版本再创建，命令：

kubectl convert -f /tmp/deployment.yaml --output-version=apps/v1 > /tmp/v1deploy.yaml

➜  ~ kubectl create -f /tmp/deployment.yaml
error: unable to recognize "/tmp/deployment.yaml": no matches for kind "Deployment" in version "apps/v1beta1"
➜  ~ kubectl convert -f /tmp/deployment.yaml --output-version=apps/v1
kubectl convert is DEPRECATED and will be removed in a future version.
In order to convert, kubectl apply the object to the cluster, then kubectl get at the desired version.
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: nginx
  name: nginx-deployment
spec:
  progressDeadlineSeconds: 600
  replicas: 3
  revisionHistoryLimit: 2
  selector:
    matchLabels:
      app: nginx
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx:1.14.2
        imagePullPolicy: IfNotPresent
        name: nginx
        ports:
        - containerPort: 80
          protocol: TCP
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30
status: {}
➜  ~ kubectl convert -f /tmp/deployment.yaml --output-version=apps/v1 > /tmp/v1deploy.yaml
kubectl convert is DEPRECATED and will be removed in a future version.
In order to convert, kubectl apply the object to the cluster, then kubectl get at the desired version.
➜  ~ kubectl create -f /tmp/v1deploy.yaml
deployment.apps/nginx-deployment created
➜  ~ kubectl get pod --all-namespaces
NAMESPACE              NAME                                        READY   STATUS    RESTARTS      AGE
default                nginx-deployment-9456bbbf9-78z87            1/1     Running   0             27s
default                nginx-deployment-9456bbbf9-7tgnm            1/1     Running   0             27s
default                nginx-deployment-9456bbbf9-n4mch            1/1     Running   0             27s