背景

笔者最近接到一则任务，大体目标是将线上某个k8s集群下掉（降低研发成本、运维成本，统一k8s集群版本），原集群中的服务需要在另一个集群中创建出来，主要涉及到三块内容：
Deployment、Service、PV和PVC

作为一名合格的”YAML工程师”，想到通过kubectl从旧集群导出所有的YAML文件，往新集群一提交，是不是就完事了？实际操作下来，发现导出的文件中有很多由k8s控制器自动添加的字段，如
metadata下的resourceVersion、selfLink、uid和status等，尤其是resourceVersion，如果不删除此字段，直接往新集群提交文件，会出现报错无法往下进行

工具

也有工程师发现了这个痛点，在Github上开源了这款工具：https://github.com/itaysk/kubectl-neat

使用方法

• 安装方式一：作为kubectl插件

  kubectl krew install neat

• 安装方式二：下载二进制包，加入PATH路径下进行使用

笔者选择了下载二进制包的方式，下面演示下使用方式

步骤一：导出文件到本地

MacBook-Pro-WRJ:kubectl-neat wrj$ kubectl get deployment jibtest -o yaml > jibtest-deploy.yaml
MacBook-Pro-WRJ:kubectl-neat wrj$ cat jibtest-deploy.yaml 
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "2"
  creationTimestamp: "2020-08-27T04:01:16Z"
  generation: 4
  labels:
    app: jibtest
  name: jibtest
  namespace: default
  resourceVersion: "140489087"
  selfLink: /apis/extensions/v1beta1/namespaces/default/deployments/jibtest
  uid: f49d6beb-e819-11ea-b478-00163e121eee
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: jibtest
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: jibtest
    spec:
      containers:
      - image: jibtest:v3.0
        imagePullPolicy: IfNotPresent
        name: jibtest
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30
status:
  availableReplicas: 1
  conditions:
  - lastTransitionTime: "2020-08-27T04:01:16Z"
    lastUpdateTime: "2020-08-27T05:35:50Z"
    message: ReplicaSet "jibtest-596d7b848" has successfully progressed.
    reason: NewReplicaSetAvailable
    status: "True"
    type: Progressing
  - lastTransitionTime: "2020-08-29T10:34:00Z"
    lastUpdateTime: "2020-08-29T10:34:00Z"
    message: Deployment has minimum availability.
    reason: MinimumReplicasAvailable
    status: "True"
    type: Available
  observedGeneration: 4
  readyReplicas: 1
  replicas: 1
  updatedReplicas: 1

步骤二：通过工具删除多余字段，生成一份新文件

MacBook-Pro-WRJ:kubectl-neat wrj$ kubectl-neat -f jibtest-deploy.yaml > jibtest-deploy-neat.yaml
MacBook-Pro-WRJ:kubectl-neat wrj$ cat jibtest-deploy-neat.yaml 
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "2"
  labels:
    app: jibtest
  name: jibtest
  namespace: default
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: jibtest
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: jibtest
    spec:
      containers:
      - image: harbor-test-k8s.dui88.com/library/jibtest:v3.0
        imagePullPolicy: IfNotPresent
        name: jibtest
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      terminationGracePeriodSeconds: 30

步骤三：往新集群提交新部署文件

MacBook-Pro-WRJ:kubectl-neat wrj$ kubect apply -f jibtest-deploy-neat.yaml

经过以上步骤，完成一个deployment的迁移工作，其他service等资源类似