We talked about deployments briefly in Chapter 1, Introduction to Kubernetes for Developers, and we've used Kubernetes deployments in almost every chapter. However, before diving into more sophisticated patterns and strategies, it will be useful to review the basic building blocks and the relationships between Kubernetes deployments, Kubernetes services, and scaling or autoscaling.
Deployments are Kubernetes resources that manage pods via a ReplicaSet. A Kubernetes ReplicaSet is a group of pods that are identified by a common set of labels with a certain number of replicas. The connection between the ReplicaSet to its pods is the ownerReferences field in the pod's metadata. The ReplicaSet controller ensures that the correct number of replicas are always running. If a pod dies for whatever reason, the ReplicaSet controller will schedule a new pod...
