--replicas flag has been deprecated

[IAmATeaPot418]

Commands in chapter 8 rely on the depreciated replicas. This is several places throughout the book.

It was removed in 1.18.

https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.18.md#deprecation-4

kubectl run be-default \

--image=gcr.io/kuar-demo/kuard-amd64:blue
--replicas=3
--port=8080 Flag --replicas has been deprecated, has no effect and will be removed in the future. pod/be-default created

[SergiyKolesnikov]

The closest alternative with which I could come up for a command such as

kubectl run alpaca-prod --image=gcr.io/kuar-demo/kuard-amd64:blue --replicas=3 --port=8080 --labels="ver=1,app=alpaca,env=prod"

would be to do the following:

Run

kubectl create deployment alpaca-prod --image=gcr.io/kuar-demo/kuard-amd64:blue --replicas=3 --port=8080 --output yaml --dry-run=client >alpaca-prod.yaml

The command will create alpaca-prod.yaml with the content

apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: alpaca-prod
  name: alpaca-prod
spec:
  replicas: 3
  selector:
    matchLabels:
      app: alpaca-prod
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: alpaca-prod
    spec:
      containers:
      - image: gcr.io/kuar-demo/kuard-amd64:blue
        name: kuard-amd64
        ports:
        - containerPort: 8080
        resources: {}
status: {}

Edit metadata.labels, spec.selector.matchLabels, spec.template.metadata.labels to included the labels from the run command:

apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  name: alpaca-prod
  labels:
    app: alpaca
    ver: "1"
    env: prod
spec:
  replicas: 3
  selector:
    matchLabels:
      app: alpaca
      ver: "1"
      env: prod
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: alpaca
        ver: "1"
        env: prod
    spec:
      containers:
      - image: gcr.io/kuar-demo/kuard-amd64:blue
        name: kuard-amd64
        ports:
        - containerPort: 8080
        resources: {}
status: {}

Run

kubectl apply -f alpaca-prod.yaml

[lachie83]

Thank you for raising this issue. We've updated this in the 3rd edition to something similar to the following

# First, create the deployment
$ kubectl create deployment alpaca-prod --image=[gcr.io/kuar-demo/kuard-amd64:blue](http://gcr.io/kuar-demo/kuard-amd64:blue) --replicas=2
# After the deployment is created, you can add some labels
$ kubectl label deployments alpaca-prod --overwrite ver=1 app=alpaca env=prod