Summary - StatefulSet

Combine YAML and volumeClaimTemplate to write a StatefulSet.

Summary: StatefulSet

In this group:

A StatefulSet is for stateful applications: stable ordinal names, stable network names, persistent storage per pod.
serviceName points at a headless service (clusterIP: None); pod DNS is db-0.db.
volumeClaimTemplates creates a PVC (data-db-0) for each pod; PVCs remain when the pod and StatefulSet are deleted.
OrderedReady starts in order and scales down in reverse; Parallel starts without waiting.
Updates proceed in reverse; partition enables canary updates.

kubectl get sts,pvc -l app=db
kubectl scale sts db --replicas=5

Write a Service YAML: name db; clusterIP: None; selector app: db; port 5432.

Show example solution

apiVersion: v1
kind: Service
metadata:
  name: db
spec:
  clusterIP: None
  selector:
    app: db
  ports:
    - port: 5432

Scale the StatefulSet.

kubectl scale ____ db --replicas=5

Show answer

kubectl scale sts db --replicas=5