K8s storage: emptyDir

• https://kubernetes.io/docs/concepts/storage/volumes/#emptydir

Official example

apiVersion: v1
kind: Pod
metadata:
  name: test-pd
spec:
  containers:
  - image: registry.k8s.io/test-webserver
    name: test-container
    volumeMounts:
    - mountPath: /cache
      name: cache-volume
  volumes:
  - name: cache-volume
    emptyDir:
      sizeLimit: 500Mi
      medium: Memory

/tmp example

apiVersion: v1
kind: Pod
metadata:
  name: test-pod
spec:
  containers:
  - image: registry.k8s.io/test-webserver
    name: test-container
    securityContext:
      readOnlyRootFilesystem: true
    volumeMounts:
    - mountPath: /tmp
      name: tmp-volume
  volumes:
  - name: tmp-volume
    emptyDir:
      sizeLimit: 1G

Additional examples

extraVolumes:
 - name: extras
   emptyDir: {}

extraVolumeMounts:
 - name: extras
   mountPath: /usr/share/extras
   readOnly: true

kubectl get psp
Warning: policy/v1beta1 PodSecurityPolicy is deprecated in v1.21+, unavailable in v1.25+
NAME                    PRIV    CAPS   SELINUX    RUNASUSER   FSGROUP    SUPGROUP   READONLYROOTFS   VOLUMES
gce.gke-metrics-agent   false          RunAsAny   RunAsAny    RunAsAny   RunAsAny   false            hostPath,secret,configMap
grafana                 false          RunAsAny   RunAsAny    RunAsAny   RunAsAny   false            configMap,emptyDir,projected,secret,downwardAPI,persistentVolumeClaim

kubectl get psp
Warning: policy/v1beta1 PodSecurityPolicy is deprecated in v1.21+, unavailable in v1.25+
NAME                    PRIV    CAPS   SELINUX    RUNASUSER   FSGROUP    SUPGROUP   READONLYROOTFS   VOLUMES
gce.gke-metrics-agent   false          RunAsAny   RunAsAny    RunAsAny   RunAsAny   false            hostPath,secret,configMap

Related

• --volumes-from
• readOnlyRootFilesystem in spec.containers.securityContext
• /tmp/
• tmpfs

See also

• emptyDir, readOnlyRootFilesystem
• Kubernetes volumes: volumeMounts:, mountPath, snapshots, spec.volumes, projected volumes, PVC
• 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, Rook, Longhorn, projected volumes