Kubernetes deployment: Pods from a service are being scheduled on the same node

I was trying to deploy pulsar using GKE. While I was deploying the ZooKeeper service I noticed that its pods were being scheduled on the same node. I am really new to Kubernetes but this looks a little odd to me:

deployment/kubernetes/google-kubernetes-engine/zookeeper.yaml

spec:
    serviceName: zookeeper
    replicas: 3
    template:
        metadata:
            labels:
                app: pulsar
                component: zookeeper
                cluster: pulsar-gke
            annotations:
                pod.alpha.kubernetes.io/initialized: "true"
                prometheus.io/scrape: "true"
                prometheus.io/port: "8080"

        spec:
            # Make sure multiple pods of ZK don't get scheduled on the
            # same node, unless there are no other available nodes
            affinity:
                podAntiAffinity:
                    preferredDuringSchedulingIgnoredDuringExecution:
                      - weight: 1
                        podAffinityTerm:
                            labelSelector:
                                matchExpressions:
                                  - key: "app"
                                    operator: In
                                    values:
                                      - zookeeper
                            topologyKey: "kubernetes.io/hostname"

I read this Kubernetes affinity example and I think that the key used in matchExpressions should be component, not app. When I use component as the key, all the ZooKeeper pods are scheduled on different nodes.

If I am correct, this error is present in all the Kubernetes deployment files.

Is there any Kubernetes expert willing to take a look at this?

Thank you!

[stupidusername]

@cdbartholomew Thanks for submitting the PR!

[ghost]

they put component in this one here