How does a replica determine which pods it should manage?

A ReplicaSet in Kubernetes defines which pods it manages using a label selector. The ReplicaSet manifest specifies the selector field, which contains criteria for selecting pods based on their labels. The ReplicaSet monitors pods whose labels match this selector and maintains the desired number of such pods by creating or deleting them as needed.

Example of a selector in a ReplicaSet:

selector:
  matchLabels:
    app: myapp

In this case, the ReplicaSet manages all pods with the label app: myapp.