StatefulSets

StatefulSet

• https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/

kubectl get statefulsets
kubectl describe statefulsets

kubectl get statefulsets -n your_namespace
NAME                   READY   AGE
your-elasticsearch-master   0/2     2y88d

33m         Warning   CalculateExpectedPodCountFailed   poddisruptionbudget/xxxx-pdb                     Failed to calculate the number of  expected pods: statefulsets.apps does not implement the scale subresource

Official example

apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  ports:
  - port: 80
    name: web
  clusterIP: None
  selector:
    app: nginx
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  selector:
    matchLabels:
      app: nginx # has to match .spec.template.metadata.labels
  serviceName: "nginx"
  replicas: 3 # by default is 1
  minReadySeconds: 10 # by default is 0
  template:
    metadata:
      labels:
        app: nginx # has to match .spec.selector.matchLabels
    spec:
      terminationGracePeriodSeconds: 10
      containers:
      - name: nginx
        image: k8s.gcr.io/nginx-slim:0.8
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: www
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates:
  - metadata:
      name: www
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: "my-storage-class"
      resources:
        requests:
          storage: 1Gi

Related

• Peloton
• kubectl rollout
• Elastic Cloud on Kubernetes (ECK) (May 2019)

See also

• StatefulSets (sts): kubectl [ get | describe | scale ] statefulset
• Kubernetes storage, storage classes, PersistentVolume (PV), PVC, CSI, kind: StorageClass, kind: PersistentVolumeClaim, kind: PersistentVolume, kubectl [ get | describe | edit ] pvc, volumeClaimTemplates:, kubectl patch pv, FailedMount, Volume Expansion, Volume Cloning, snapshots, ExtraVolumes, NotTriggerScaleUp, volumePVCDataSource, AllowVolumeExpansion, EKS storage, provisioner, Storage Capacity Tracking, VolumeBinding, VolumeClaimTemplate, storage.k8s.io, CKA Storage, DoKC, EmptyDir, Volume populators, storageclass.kubernetes.io