Error when trying to create Kubernetes deployment - Invalid spec.selector-CodePudding

I am trying to create a kubernetes deployment. Here is the manifest:

server-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: server-deployment
spec:
  replicas: 1
  selector:
    matchLabels:
      tier: server
  template:
    metadata:
      labels:
        tier: server
    spec:
      containers:
        - image: rocketblast2481/chatto-server
          name: server-container
          imagePullPolicy: Always

Then I run the following command:

kubectl apply -f=server-deployment.yaml

But then I get the following error:

The Deployment "server-deployment" is invalid: spec.selector: Invalid value: v1.LabelSelector{MatchLabels:map[string]string{"tier":"server"}, MatchExpressions:[]v1.LabelSelectorRequirement(nil)}: field is immutabl

CodePudding user response：

It looks like you are trying to update deployment selector. Which is not possible. To update selector first delete existing deployment using. kubectl delete deployment server-deployment Then run kubectl apply -f server-deployment.yml

CodePudding user response：

Once a deployment spec is deployed the selector become immutable, this means you cannot change it by re-apply with updated spec.

Note: In API version apps/v1, a Deployment's label selector is immutable after it gets created.