why the postgersql kubernetes statefulset did not claim the PVC - postgresql

Question

Today I want to change the PostgreSQL statefulset PVC name, to my surprise, I did not found any clain about the PVC in the kubernetes deployment define, this is the kubernetes deployment define of PostgreSQL:
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: reddwarf-postgresql-postgresql
namespace: reddwarf-storage
uid: 787a18c8-f6fb-4deb-bb07-3c3d123cf6f9
resourceVersion: '21931453'
generation: 30
creationTimestamp: '2021-08-05T05:29:03Z'
labels:
app.kubernetes.io/component: primary
app.kubernetes.io/instance: reddwarf-postgresql
app.kubernetes.io/managed-by: Helm
app.kubernetes.io/name: postgresql
helm.sh/chart: postgresql-10.9.1
annotations:
kubectl.kubernetes.io/last-applied-configuration: >
{"apiVersion":"apps/v1","kind":"StatefulSet","metadata":{"annotations":{"meta.helm.sh/release-name":"reddwarf-postgresql","meta.helm.sh/release-namespace":"reddwarf-storage"},"creationTimestamp":"2021-08-05T05:29:03Z","generation":12,"labels":{"app.kubernetes.io/component":"primary","app.kubernetes.io/instance":"reddwarf-postgresql","app.kubernetes.io/managed-by":"Helm","app.kubernetes.io/name":"postgresql","helm.sh/chart":"postgresql-10.9.1"},"managedFields":[{"apiVersion":"apps/v1","fieldsType":"FieldsV1","fieldsV1":{"f:metadata":{"f:annotations":{".":{},"f:meta.helm.sh/release-name":{},"f:meta.helm.sh/release-namespace":{}},"f:labels":{".":{},"f:app.kubernetes.io/component":{},"f:app.kubernetes.io/instance":{},"f:app.kubernetes.io/managed-by":{},"f:app.kubernetes.io/name":{},"f:helm.sh/chart":{}}},"f:spec":{"f:podManagementPolicy":{},"f:replicas":{},"f:revisionHistoryLimit":{},"f:selector":{},"f:serviceName":{},"f:template":{"f:metadata":{"f:labels":{".":{},"f:app.kubernetes.io/component":{},"f:app.kubernetes.io/instance":{},"f:app.kubernetes.io/managed-by":{},"f:app.kubernetes.io/name":{},"f:helm.sh/chart":{},"f:role":{}},"f:name":{}},"f:spec":{"f:affinity":{".":{},"f:podAntiAffinity":{".":{},"f:preferredDuringSchedulingIgnoredDuringExecution":{}}},"f:automountServiceAccountToken":{},"f:containers":{"k:{\"name\":\"reddwarf-postgresql\"}":{".":{},"f:env":{".":{},"k:{\"name\":\"BITNAMI_DEBUG\"}":{".":{},"f:name":{},"f:value":{}},"k:{\"name\":\"PGDATA\"}":{".":{},"f:name":{},"f:value":{}},"k:{\"name\":\"POSTGRESQL_CLIENT_MIN_MESSAGES\"}":{".":{},"f:name":{},"f:value":{}},"k:{\"name\":\"POSTGRESQL_ENABLE_LDAP\"}":{".":{},"f:name":{},"f:value":{}},"k:{\"name\":\"POSTGRESQL_ENABLE_TLS\"}":{".":{},"f:name":{},"f:value":{}},"k:{\"name\":\"POSTGRESQL_LOG_CONNECTIONS\"}":{".":{},"f:name":{},"f:value":{}},"k:{\"name\":\"POSTGRESQL_LOG_DISCONNECTIONS\"}":{".":{},"f:name":{},"f:value":{}},"k:{\"name\":\"POSTGRESQL_LOG_HOSTNAME\"}":{".":{},"f:name":{},"f:value":{}},"k:{\"name\":\"POSTGRESQL_PGAUDIT_LOG_CATALOG\"}":{".":{},"f:name":{},"f:value":{}},"k:{\"name\":\"POSTGRESQL_PORT_NUMBER\"}":{".":{},"f:name":{},"f:value":{}},"k:{\"name\":\"POSTGRESQL_SHARED_PRELOAD_LIBRARIES\"}":{".":{},"f:name":{},"f:value":{}},"k:{\"name\":\"POSTGRESQL_VOLUME_DIR\"}":{".":{},"f:name":{},"f:value":{}},"k:{\"name\":\"POSTGRES_PASSWORD\"}":{".":{},"f:name":{},"f:valueFrom":{".":{},"f:secretKeyRef":{".":{},"f:key":{},"f:name":{}}}},"k:{\"name\":\"POSTGRES_USER\"}":{".":{},"f:name":{},"f:value":{}}},"f:imagePullPolicy":{},"f:livenessProbe":{".":{},"f:exec":{".":{},"f:command":{}},"f:failureThreshold":{},"f:initialDelaySeconds":{},"f:periodSeconds":{},"f:successThreshold":{},"f:timeoutSeconds":{}},"f:name":{},"f:ports":{".":{},"k:{\"containerPort\":5432,\"protocol\":\"TCP\"}":{".":{},"f:containerPort":{},"f:name":{},"f:protocol":{}}},"f:readinessProbe":{".":{},"f:exec":{".":{},"f:command":{}},"f:failureThreshold":{},"f:initialDelaySeconds":{},"f:periodSeconds":{},"f:successThreshold":{},"f:timeoutSeconds":{}},"f:resources":{".":{},"f:requests":{".":{},"f:cpu":{},"f:memory":{}}},"f:securityContext":{".":{},"f:runAsUser":{}},"f:terminationMessagePath":{},"f:terminationMessagePolicy":{},"f:volumeMounts":{".":{},"k:{\"mountPath\":\"/bitnami/postgresql\"}":{".":{},"f:mountPath":{},"f:name":{}},"k:{\"mountPath\":\"/dev/shm\"}":{".":{},"f:mountPath":{},"f:name":{}}}}},"f:dnsPolicy":{},"f:restartPolicy":{},"f:schedulerName":{},"f:securityContext":{".":{},"f:fsGroup":{}},"f:terminationGracePeriodSeconds":{},"f:volumes":{".":{},"k:{\"name\":\"dshm\"}":{".":{},"f:emptyDir":{".":{},"f:medium":{}},"f:name":{}}}}},"f:updateStrategy":{"f:type":{}},"f:volumeClaimTemplates":{}}},"manager":"Go-http-client","operation":"Update","time":"2021-08-05T05:29:03Z"},{"apiVersion":"apps/v1","fieldsType":"FieldsV1","fieldsV1":{"f:spec":{"f:template":{"f:spec":{"f:containers":{"k:{\"name\":\"reddwarf-postgresql\"}":{"f:image":{}}}}}}},"manager":"kubectl-client-side-apply","operation":"Update","time":"2021-08-10T16:50:45Z"},{"apiVersion":"apps/v1","fieldsType":"FieldsV1","fieldsV1":{"f:metadata":{"f:annotations":{"f:kubectl.kubernetes.io/last-applied-configuration":{}}},"f:spec":{"f:template":{"f:spec":{"f:containers":{"k:{\"name\":\"reddwarf-postgresql\"}":{"f:args":{}}}}}}},"manager":"kubectl","operation":"Update","time":"2021-08-11T01:46:21Z"},{"apiVersion":"apps/v1","fieldsType":"FieldsV1","fieldsV1":{"f:status":{"f:collisionCount":{},"f:currentReplicas":{},"f:currentRevision":{},"f:observedGeneration":{},"f:replicas":{},"f:updateRevision":{},"f:updatedReplicas":{}}},"manager":"kube-controller-manager","operation":"Update","time":"2021-08-11T02:24:07Z"}],"name":"reddwarf-postgresql-postgresql","namespace":"reddwarf-storage","selfLink":"/apis/apps/v1/namespaces/reddwarf-storage/statefulsets/reddwarf-postgresql-postgresql","uid":"787a18c8-f6fb-4deb-bb07-3c3d123cf6f9"},"spec":{"podManagementPolicy":"OrderedReady","replicas":1,"revisionHistoryLimit":10,"selector":{"matchLabels":{"app.kubernetes.io/instance":"reddwarf-postgresql","app.kubernetes.io/name":"postgresql","role":"primary"}},"serviceName":"reddwarf-postgresql-headless","template":{"metadata":{"creationTimestamp":null,"labels":{"app.kubernetes.io/component":"primary","app.kubernetes.io/instance":"reddwarf-postgresql","app.kubernetes.io/managed-by":"Helm","app.kubernetes.io/name":"postgresql","helm.sh/chart":"postgresql-10.9.1","role":"primary"},"name":"reddwarf-postgresql"},"spec":{"affinity":{"podAntiAffinity":{"preferredDuringSchedulingIgnoredDuringExecution":[{"podAffinityTerm":{"labelSelector":{"matchLabels":{"app.kubernetes.io/component":"primary","app.kubernetes.io/instance":"reddwarf-postgresql","app.kubernetes.io/name":"postgresql"}},"namespaces":["reddwarf-storage"],"topologyKey":"kubernetes.io/hostname"},"weight":1}]}},"automountServiceAccountToken":false,"containers":[{"env":[{"name":"BITNAMI_DEBUG","value":"false"},{"name":"POSTGRESQL_PORT_NUMBER","value":"5432"},{"name":"POSTGRESQL_VOLUME_DIR","value":"/bitnami/postgresql"},{"name":"PGDATA","value":"/bitnami/postgresql/data"},{"name":"POSTGRES_USER","value":"postgres"},{"name":"POSTGRES_PASSWORD","valueFrom":{"secretKeyRef":{"key":"postgresql-password","name":"reddwarf-postgresql"}}},{"name":"POSTGRESQL_ENABLE_LDAP","value":"no"},{"name":"POSTGRESQL_ENABLE_TLS","value":"no"},{"name":"POSTGRESQL_LOG_HOSTNAME","value":"false"},{"name":"POSTGRESQL_LOG_CONNECTIONS","value":"false"},{"name":"POSTGRESQL_LOG_DISCONNECTIONS","value":"false"},{"name":"POSTGRESQL_PGAUDIT_LOG_CATALOG","value":"off"},{"name":"POSTGRESQL_CLIENT_MIN_MESSAGES","value":"error"},{"name":"POSTGRESQL_SHARED_PRELOAD_LIBRARIES","value":"pgaudit"}],"image":"docker.io/bitnami/postgresql:13.3.0-debian-10-r75","imagePullPolicy":"IfNotPresent","livenessProbe":{"exec":{"command":["/bin/sh","-c","exec
pg_isready -U \"postgres\" -h 127.0.0.1 -p
5432"]},"failureThreshold":6,"initialDelaySeconds":30,"periodSeconds":10,"successThreshold":1,"timeoutSeconds":5},"name":"reddwarf-postgresql","ports":[{"containerPort":5432,"name":"tcp-postgresql","protocol":"TCP"}],"readinessProbe":{"exec":{"command":["/bin/sh","-c","-e","exec
pg_isready -U \"postgres\" -h 127.0.0.1 -p 5432\n[ -f
/opt/bitnami/postgresql/tmp/.initialized ] || [ -f
/bitnami/postgresql/.initialized
]\n"]},"failureThreshold":6,"initialDelaySeconds":5,"periodSeconds":10,"successThreshold":1,"timeoutSeconds":5},"resources":{"requests":{"cpu":"250m","memory":"256Mi"}},"securityContext":{"runAsUser":1001},"terminationMessagePath":"/dev/termination-log","terminationMessagePolicy":"File","volumeMounts":[{"mountPath":"/dev/shm","name":"dshm"},{"mountPath":"/bitnami/postgresql","name":"data"}]}],"dnsPolicy":"ClusterFirst","restartPolicy":"Always","schedulerName":"default-scheduler","securityContext":{"fsGroup":1001},"terminationGracePeriodSeconds":30,"volumes":[{"emptyDir":{"medium":"Memory"},"name":"dshm"}]}},"updateStrategy":{"type":"RollingUpdate"},"volumeClaimTemplates":[{"apiVersion":"v1","kind":"PersistentVolumeClaim","metadata":{"creationTimestamp":null,"name":"data"},"spec":{"accessModes":["ReadWriteOnce"],"resources":{"requests":{"storage":"8Gi"}},"volumeMode":"Filesystem"},"status":{"phase":"Pending"}}]}}
meta.helm.sh/release-name: reddwarf-postgresql
meta.helm.sh/release-namespace: reddwarf-storage
managedFields:
- manager: Go-http-client
operation: Update
apiVersion: apps/v1
time: '2021-08-05T05:29:03Z'
fieldsType: FieldsV1
fieldsV1:
'f:metadata':
'f:annotations':
.: {}
'f:meta.helm.sh/release-name': {}
'f:meta.helm.sh/release-namespace': {}
'f:labels':
.: {}
'f:app.kubernetes.io/component': {}
'f:app.kubernetes.io/instance': {}
'f:app.kubernetes.io/managed-by': {}
'f:app.kubernetes.io/name': {}
'f:helm.sh/chart': {}
'f:spec':
'f:podManagementPolicy': {}
'f:replicas': {}
'f:revisionHistoryLimit': {}
'f:selector': {}
'f:serviceName': {}
'f:template':
'f:metadata':
'f:labels':
.: {}
'f:app.kubernetes.io/component': {}
'f:app.kubernetes.io/instance': {}
'f:app.kubernetes.io/managed-by': {}
'f:app.kubernetes.io/name': {}
'f:helm.sh/chart': {}
'f:role': {}
'f:name': {}
'f:spec':
'f:affinity':
.: {}
'f:podAntiAffinity':
.: {}
'f:preferredDuringSchedulingIgnoredDuringExecution': {}
'f:automountServiceAccountToken': {}
'f:containers':
'k:{"name":"reddwarf-postgresql"}':
.: {}
'f:env':
.: {}
'k:{"name":"BITNAMI_DEBUG"}':
.: {}
'f:name': {}
'f:value': {}
'k:{"name":"PGDATA"}':
.: {}
'f:name': {}
'f:value': {}
'k:{"name":"POSTGRESQL_CLIENT_MIN_MESSAGES"}':
.: {}
'f:name': {}
'f:value': {}
'k:{"name":"POSTGRESQL_ENABLE_LDAP"}':
.: {}
'f:name': {}
'f:value': {}
'k:{"name":"POSTGRESQL_ENABLE_TLS"}':
.: {}
'f:name': {}
'f:value': {}
'k:{"name":"POSTGRESQL_LOG_CONNECTIONS"}':
.: {}
'f:name': {}
'f:value': {}
'k:{"name":"POSTGRESQL_LOG_DISCONNECTIONS"}':
.: {}
'f:name': {}
'f:value': {}
'k:{"name":"POSTGRESQL_LOG_HOSTNAME"}':
.: {}
'f:name': {}
'f:value': {}
'k:{"name":"POSTGRESQL_PGAUDIT_LOG_CATALOG"}':
.: {}
'f:name': {}
'f:value': {}
'k:{"name":"POSTGRESQL_PORT_NUMBER"}':
.: {}
'f:name': {}
'f:value': {}
'k:{"name":"POSTGRESQL_SHARED_PRELOAD_LIBRARIES"}':
.: {}
'f:name': {}
'f:value': {}
'k:{"name":"POSTGRESQL_VOLUME_DIR"}':
.: {}
'f:name': {}
'f:value': {}
'k:{"name":"POSTGRES_PASSWORD"}':
.: {}
'f:name': {}
'f:valueFrom':
.: {}
'f:secretKeyRef':
.: {}
'f:key': {}
'f:name': {}
'k:{"name":"POSTGRES_USER"}':
.: {}
'f:name': {}
'f:value': {}
'f:imagePullPolicy': {}
'f:livenessProbe':
.: {}
'f:exec':
.: {}
'f:command': {}
'f:failureThreshold': {}
'f:initialDelaySeconds': {}
'f:periodSeconds': {}
'f:successThreshold': {}
'f:timeoutSeconds': {}
'f:name': {}
'f:ports':
.: {}
'k:{"containerPort":5432,"protocol":"TCP"}':
.: {}
'f:containerPort': {}
'f:name': {}
'f:protocol': {}
'f:readinessProbe':
.: {}
'f:exec':
.: {}
'f:command': {}
'f:failureThreshold': {}
'f:initialDelaySeconds': {}
'f:periodSeconds': {}
'f:successThreshold': {}
'f:timeoutSeconds': {}
'f:resources':
.: {}
'f:requests':
.: {}
'f:cpu': {}
'f:memory': {}
'f:securityContext':
.: {}
'f:runAsUser': {}
'f:terminationMessagePath': {}
'f:terminationMessagePolicy': {}
'f:volumeMounts':
.: {}
'k:{"mountPath":"/bitnami/postgresql"}':
.: {}
'f:mountPath': {}
'f:name': {}
'k:{"mountPath":"/dev/shm"}':
.: {}
'f:mountPath': {}
'f:name': {}
'f:dnsPolicy': {}
'f:restartPolicy': {}
'f:schedulerName': {}
'f:securityContext':
.: {}
'f:fsGroup': {}
'f:terminationGracePeriodSeconds': {}
'f:volumes':
.: {}
'k:{"name":"dshm"}':
.: {}
'f:emptyDir':
.: {}
'f:medium': {}
'f:name': {}
'f:updateStrategy':
'f:type': {}
'f:volumeClaimTemplates': {}
- manager: kubectl-client-side-apply
operation: Update
apiVersion: apps/v1
time: '2021-08-10T16:50:45Z'
fieldsType: FieldsV1
fieldsV1:
'f:spec':
'f:template':
'f:spec':
'f:containers':
'k:{"name":"reddwarf-postgresql"}':
'f:image': {}
- manager: kubectl
operation: Update
apiVersion: apps/v1
time: '2021-08-11T02:29:20Z'
fieldsType: FieldsV1
fieldsV1:
'f:metadata':
'f:annotations':
'f:kubectl.kubernetes.io/last-applied-configuration': {}
- manager: kube-controller-manager
operation: Update
apiVersion: apps/v1
time: '2021-11-27T03:07:58Z'
fieldsType: FieldsV1
fieldsV1:
'f:status':
'f:collisionCount': {}
'f:currentRevision': {}
'f:observedGeneration': {}
'f:replicas': {}
'f:updateRevision': {}
selfLink: >-
/apis/apps/v1/namespaces/reddwarf-storage/statefulsets/reddwarf-postgresql-postgresql
status:
observedGeneration: 30
replicas: 0
currentRevision: reddwarf-postgresql-postgresql-5695cb9676
updateRevision: reddwarf-postgresql-postgresql-5695cb9676
collisionCount: 0
spec:
replicas: 0
selector:
matchLabels:
app.kubernetes.io/instance: reddwarf-postgresql
app.kubernetes.io/name: postgresql
role: primary
template:
metadata:
name: reddwarf-postgresql
creationTimestamp: null
labels:
app.kubernetes.io/component: primary
app.kubernetes.io/instance: reddwarf-postgresql
app.kubernetes.io/managed-by: Helm
app.kubernetes.io/name: postgresql
helm.sh/chart: postgresql-10.9.1
role: primary
spec:
volumes:
- name: dshm
emptyDir:
medium: Memory
containers:
- name: reddwarf-postgresql
image: 'docker.io/bitnami/postgresql:13.3.0-debian-10-r75'
ports:
- name: tcp-postgresql
containerPort: 5432
protocol: TCP
env:
- name: BITNAMI_DEBUG
value: 'false'
- name: POSTGRESQL_PORT_NUMBER
value: '5432'
- name: POSTGRESQL_VOLUME_DIR
value: /bitnami/postgresql
- name: PGDATA
value: /bitnami/postgresql/data
- name: POSTGRES_USER
value: postgres
- name: POSTGRES_PASSWORD
valueFrom:
secretKeyRef:
name: reddwarf-postgresql
key: postgresql-password
- name: POSTGRESQL_ENABLE_LDAP
value: 'no'
- name: POSTGRESQL_ENABLE_TLS
value: 'no'
- name: POSTGRESQL_LOG_HOSTNAME
value: 'false'
- name: POSTGRESQL_LOG_CONNECTIONS
value: 'false'
- name: POSTGRESQL_LOG_DISCONNECTIONS
value: 'false'
- name: POSTGRESQL_PGAUDIT_LOG_CATALOG
value: 'off'
- name: POSTGRESQL_CLIENT_MIN_MESSAGES
value: error
- name: POSTGRESQL_SHARED_PRELOAD_LIBRARIES
value: pgaudit
resources:
requests:
cpu: 250m
memory: 256Mi
volumeMounts:
- name: dshm
mountPath: /dev/shm
- name: data
mountPath: /bitnami/postgresql
livenessProbe:
exec:
command:
- /bin/sh
- '-c'
- exec pg_isready -U "postgres" -h 127.0.0.1 -p 5432
initialDelaySeconds: 30
timeoutSeconds: 5
periodSeconds: 10
successThreshold: 1
failureThreshold: 6
readinessProbe:
exec:
command:
- /bin/sh
- '-c'
- '-e'
- >
exec pg_isready -U "postgres" -h 127.0.0.1 -p 5432
[ -f /opt/bitnami/postgresql/tmp/.initialized ] || [ -f
/bitnami/postgresql/.initialized ]
initialDelaySeconds: 5
timeoutSeconds: 5
periodSeconds: 10
successThreshold: 1
failureThreshold: 6
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
imagePullPolicy: IfNotPresent
securityContext:
runAsUser: 1001
restartPolicy: Always
terminationGracePeriodSeconds: 30
dnsPolicy: ClusterFirst
automountServiceAccountToken: false
securityContext:
fsGroup: 1001
affinity:
podAntiAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- weight: 1
podAffinityTerm:
labelSelector:
matchLabels:
app.kubernetes.io/component: primary
app.kubernetes.io/instance: reddwarf-postgresql
app.kubernetes.io/name: postgresql
namespaces:
- reddwarf-storage
topologyKey: kubernetes.io/hostname
schedulerName: default-scheduler
volumeClaimTemplates:
- kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: data
creationTimestamp: null
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 8Gi
volumeMode: Filesystem
status:
phase: Pending
serviceName: reddwarf-postgresql-headless
podManagementPolicy: OrderedReady
updateStrategy:
type: RollingUpdate
revisionHistoryLimit: 10
this statefulset bind the PVC named data-reddwarf-postgresql-postgresql-0 right now, but I did not found the PVC define in this statefulset yaml. where is the PVC bind define? what should I do to change the PVC to bind to a new one? I install this PostgreSQL into kubernetes from helm chart.

Answer 1

pvc thats gets created as a part of statefulset will have a name which is an amalgamation of 3 components joined by - :
Name defined in the volumeClaimTemplates section data
Name of the statefulset in the metadata section which is reddwarf-postgresql-postgresql
Its replica number , if it is first replica then it would be 0
So finally the name of the pvc that gets created when you create this statefulset is
data-reddwarf-postgresql-postgresql-0.which is the pvc name that you also seeing in your setup.
please note when you delete the statefulset , pvc does not deleted automatically we need to pvc separately. When you recreate/scaleup the stateful set and if the pvc which matches above naming convention& spec does not exists then it will create a pvc.
From kubernetes documentation