原文：https://cloud.tencent.com/developer/article/1394657
Deployment.spec.selector.matchLables实验解释
作者: 张首富
时间: 2019-02-23 个人博客: www.zhangshoufu.com QQ群: 895291458
正确的Deployment,让matchLabels 和template.metadata.lables完全比配不报错
apiVersion: apps/v1 kind: Deployment metadata: name: my-nginx spec: selector: matchLabels: app: my-nginx replicas: 2 template: metadata: labels: app: my-nginx spec: containers: - name: my-nginx image: nginx ports: - containerPort: 80
pod创建成功
[root@rke test_yaml]# kubectl get pods NAME READY STATUS RESTARTS AGE my-nginx-9b44d8f5-d6n8z 1/1 Running 0 3s my-nginx-9b44d8f5-zzv52 1/1 Running 0 3s
直接不写spec.mathlabels创建直接报错缺少缺少必要字段selector
apiVersion: apps/v1 kind: Deployment metadata: name: my-nginx spec: replicas: 2 template: metadata: labels: run: my-nginx spec: containers: - name: my-nginx image: nginx ports: - containerPort: 80
运行报错结果如下:
[root@rke test_yaml]# kubectl create -f test_pod_svc.yaml error: error validating "test_pod_svc.yaml": error validating data: ValidationError(Deployment.spec): missing required field "selector" in io.k8s.api.apps.v1.DeploymentSpec; if you choose to ignore these errors, turn validation off with --validate=false
#当把matchLables匹配的和下面pod模板不相对应,也会直接报错,选择的和模板标签不匹配
apiVersion: apps/v1 kind: Deployment metadata: name: my-nginx spec: selector: matchLabels: app: my-nginx-add replicas: 2 template: metadata: labels: app: my-nginx spec: containers: - name: my-nginx image: nginx:1.14 ports: - containerPort: 80
运行报错结果如下:
The Deployment "my-nginx" is invalid: spec.template.metadata.labels: Invalid value: map[string]string{"app":"my-nginx"}: `selector` does not match template `labels`
查看帮助手册
kubectl explain Deployment.spec
selector <Object> Label selector for pods. Existing ReplicaSets whose pods are selected by this will be the ones affected by this deployment. pod的标签选择器。 由此选择其pod的现有ReplicaSet(副本集)将受此部署影响的副本。
#总结: 1,在Deployment中必须写matchLables, 2,在定义模板的时候必须定义labels,因为Deployment.spec.selector是必须字段,而他又必须和template.labels对应, 3,template里面定义的内容会应用到下面所有的副本集里面,在template.spec.containers里面不能定义labels标签.