Chapter 17. StatefulSet [apps/v1]
- Description
StatefulSet represents a set of pods with consistent identities. Identities are defined as: - Network: A single stable DNS and hostname. - Storage: As many VolumeClaims as requested.
The StatefulSet guarantees that a given network identity will always map to the same storage identity.
- Type
-
object
17.1. Specification
Property | Type | Description |
---|---|---|
|
| APIVersion defines the versioned schema of this representation of an object. Servers should convert recognized schemas to the latest internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources |
|
| Kind is a string value representing the REST resource this object represents. Servers may infer this from the endpoint the client submits requests to. Cannot be updated. In CamelCase. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds |
| Standard object’s metadata. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata | |
|
| A StatefulSetSpec is the specification of a StatefulSet. |
|
| StatefulSetStatus represents the current state of a StatefulSet. |
17.1.1. .spec
- Description
- A StatefulSetSpec is the specification of a StatefulSet.
- Type
-
object
- Required
-
selector
-
template
-
serviceName
-
Property | Type | Description |
---|---|---|
|
| Minimum number of seconds for which a newly created pod should be ready without any of its container crashing for it to be considered available. Defaults to 0 (pod will be considered available as soon as it is ready) |
|
| StatefulSetOrdinals describes the policy used for replica ordinal assignment in this StatefulSet. |
|
| StatefulSetPersistentVolumeClaimRetentionPolicy describes the policy used for PVCs created from the StatefulSet VolumeClaimTemplates. |
|
|
podManagementPolicy controls how pods are created during initial scale up, when replacing pods on nodes, or when scaling down. The default policy is
Possible enum values: - |
|
| replicas is the desired number of replicas of the given Template. These are replicas in the sense that they are instantiations of the same Template, but individual replicas also have a consistent identity. If unspecified, defaults to 1. |
|
| revisionHistoryLimit is the maximum number of revisions that will be maintained in the StatefulSet’s revision history. The revision history consists of all revisions not represented by a currently applied StatefulSetSpec version. The default value is 10. |
| selector is a label query over pods that should match the replica count. It must match the pod template’s labels. More info: https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#label-selectors | |
|
| serviceName is the name of the service that governs this StatefulSet. This service must exist before the StatefulSet, and is responsible for the network identity of the set. Pods get DNS/hostnames that follow the pattern: pod-specific-string.serviceName.default.svc.cluster.local where "pod-specific-string" is managed by the StatefulSet controller. |
| template is the object that describes the pod that will be created if insufficient replicas are detected. Each pod stamped out by the StatefulSet will fulfill this Template, but have a unique identity from the rest of the StatefulSet. Each pod will be named with the format <statefulsetname>-<podindex>. For example, a pod in a StatefulSet named "web" with index number "3" would be named "web-3". The only allowed template.spec.restartPolicy value is "Always". | |
|
| StatefulSetUpdateStrategy indicates the strategy that the StatefulSet controller will use to perform updates. It includes any additional parameters necessary to perform the update for the indicated strategy. |
| volumeClaimTemplates is a list of claims that pods are allowed to reference. The StatefulSet controller is responsible for mapping network identities to claims in a way that maintains the identity of a pod. Every claim in this list must have at least one matching (by name) volumeMount in one container in the template. A claim in this list takes precedence over any volumes in the template, with the same name. |
17.1.2. .spec.ordinals
- Description
- StatefulSetOrdinals describes the policy used for replica ordinal assignment in this StatefulSet.
- Type
-
object
Property | Type | Description |
---|---|---|
|
| start is the number representing the first replica’s index. It may be used to number replicas from an alternate index (eg: 1-indexed) over the default 0-indexed names, or to orchestrate progressive movement of replicas from one StatefulSet to another. If set, replica indices will be in the range: [.spec.ordinals.start, .spec.ordinals.start + .spec.replicas). If unset, defaults to 0. Replica indices will be in the range: [0, .spec.replicas). |
17.1.3. .spec.persistentVolumeClaimRetentionPolicy
- Description
- StatefulSetPersistentVolumeClaimRetentionPolicy describes the policy used for PVCs created from the StatefulSet VolumeClaimTemplates.
- Type
-
object
Property | Type | Description |
---|---|---|
|
|
WhenDeleted specifies what happens to PVCs created from StatefulSet VolumeClaimTemplates when the StatefulSet is deleted. The default policy of |
|
|
WhenScaled specifies what happens to PVCs created from StatefulSet VolumeClaimTemplates when the StatefulSet is scaled down. The default policy of |
17.1.4. .spec.updateStrategy
- Description
- StatefulSetUpdateStrategy indicates the strategy that the StatefulSet controller will use to perform updates. It includes any additional parameters necessary to perform the update for the indicated strategy.
- Type
-
object
Property | Type | Description |
---|---|---|
|
| RollingUpdateStatefulSetStrategy is used to communicate parameter for RollingUpdateStatefulSetStrategyType. |
|
| Type indicates the type of the StatefulSetUpdateStrategy. Default is RollingUpdate.
Possible enum values: - |
17.1.5. .spec.updateStrategy.rollingUpdate
- Description
- RollingUpdateStatefulSetStrategy is used to communicate parameter for RollingUpdateStatefulSetStrategyType.
- Type
-
object
Property | Type | Description |
---|---|---|
| The maximum number of pods that can be unavailable during the update. Value can be an absolute number (ex: 5) or a percentage of desired pods (ex: 10%). Absolute number is calculated from percentage by rounding up. This can not be 0. Defaults to 1. This field is alpha-level and is only honored by servers that enable the MaxUnavailableStatefulSet feature. The field applies to all pods in the range 0 to Replicas-1. That means if there is any unavailable pod in the range 0 to Replicas-1, it will be counted towards MaxUnavailable. | |
|
| Partition indicates the ordinal at which the StatefulSet should be partitioned for updates. During a rolling update, all pods from ordinal Replicas-1 to Partition are updated. All pods from ordinal Partition-1 to 0 remain untouched. This is helpful in being able to do a canary based deployment. The default value is 0. |
17.1.6. .status
- Description
- StatefulSetStatus represents the current state of a StatefulSet.
- Type
-
object
- Required
-
replicas
-
Property | Type | Description |
---|---|---|
|
| Total number of available pods (ready for at least minReadySeconds) targeted by this statefulset. |
|
| collisionCount is the count of hash collisions for the StatefulSet. The StatefulSet controller uses this field as a collision avoidance mechanism when it needs to create the name for the newest ControllerRevision. |
|
| Represents the latest available observations of a statefulset’s current state. |
|
| StatefulSetCondition describes the state of a statefulset at a certain point. |
|
| currentReplicas is the number of Pods created by the StatefulSet controller from the StatefulSet version indicated by currentRevision. |
|
| currentRevision, if not empty, indicates the version of the StatefulSet used to generate Pods in the sequence [0,currentReplicas). |
|
| observedGeneration is the most recent generation observed for this StatefulSet. It corresponds to the StatefulSet’s generation, which is updated on mutation by the API Server. |
|
| readyReplicas is the number of pods created for this StatefulSet with a Ready Condition. |
|
| replicas is the number of Pods created by the StatefulSet controller. |
|
| updateRevision, if not empty, indicates the version of the StatefulSet used to generate Pods in the sequence [replicas-updatedReplicas,replicas) |
|
| updatedReplicas is the number of Pods created by the StatefulSet controller from the StatefulSet version indicated by updateRevision. |
17.1.7. .status.conditions
- Description
- Represents the latest available observations of a statefulset’s current state.
- Type
-
array
17.1.8. .status.conditions[]
- Description
- StatefulSetCondition describes the state of a statefulset at a certain point.
- Type
-
object
- Required
-
type
-
status
-
Property | Type | Description |
---|---|---|
| Last time the condition transitioned from one status to another. | |
|
| A human readable message indicating details about the transition. |
|
| The reason for the condition’s last transition. |
|
| Status of the condition, one of True, False, Unknown. |
|
| Type of statefulset condition. |
17.2. API endpoints
The following API endpoints are available:
/apis/apps/v1/statefulsets
-
GET
: list or watch objects of kind StatefulSet
-
/apis/apps/v1/watch/statefulsets
-
GET
: watch individual changes to a list of StatefulSet. deprecated: use the 'watch' parameter with a list operation instead.
-
/apis/apps/v1/namespaces/{namespace}/statefulsets
-
DELETE
: delete collection of StatefulSet -
GET
: list or watch objects of kind StatefulSet -
POST
: create a StatefulSet
-
/apis/apps/v1/watch/namespaces/{namespace}/statefulsets
-
GET
: watch individual changes to a list of StatefulSet. deprecated: use the 'watch' parameter with a list operation instead.
-
/apis/apps/v1/namespaces/{namespace}/statefulsets/{name}
-
DELETE
: delete a StatefulSet -
GET
: read the specified StatefulSet -
PATCH
: partially update the specified StatefulSet -
PUT
: replace the specified StatefulSet
-
/apis/apps/v1/watch/namespaces/{namespace}/statefulsets/{name}
-
GET
: watch changes to an object of kind StatefulSet. deprecated: use the 'watch' parameter with a list operation instead, filtered to a single item with the 'fieldSelector' parameter.
-
/apis/apps/v1/namespaces/{namespace}/statefulsets/{name}/status
-
GET
: read status of the specified StatefulSet -
PATCH
: partially update status of the specified StatefulSet -
PUT
: replace status of the specified StatefulSet
-
17.2.1. /apis/apps/v1/statefulsets
- HTTP method
-
GET
- Description
- list or watch objects of kind StatefulSet
HTTP code | Reponse body |
---|---|
200 - OK |
|
401 - Unauthorized | Empty |
17.2.2. /apis/apps/v1/watch/statefulsets
- HTTP method
-
GET
- Description
- watch individual changes to a list of StatefulSet. deprecated: use the 'watch' parameter with a list operation instead.
HTTP code | Reponse body |
---|---|
200 - OK |
|
401 - Unauthorized | Empty |
17.2.3. /apis/apps/v1/namespaces/{namespace}/statefulsets
- HTTP method
-
DELETE
- Description
- delete collection of StatefulSet
Parameter | Type | Description |
---|---|---|
|
| When present, indicates that modifications should not be persisted. An invalid or unrecognized dryRun directive will result in an error response and no further processing of the request. Valid values are: - All: all dry run stages will be processed |
HTTP code | Reponse body |
---|---|
200 - OK |
|
401 - Unauthorized | Empty |
- HTTP method
-
GET
- Description
- list or watch objects of kind StatefulSet
HTTP code | Reponse body |
---|---|
200 - OK |
|
401 - Unauthorized | Empty |
- HTTP method
-
POST
- Description
- create a StatefulSet
Parameter | Type | Description |
---|---|---|
|
| When present, indicates that modifications should not be persisted. An invalid or unrecognized dryRun directive will result in an error response and no further processing of the request. Valid values are: - All: all dry run stages will be processed |
|
| fieldValidation instructs the server on how to handle objects in the request (POST/PUT/PATCH) containing unknown or duplicate fields. Valid values are: - Ignore: This will ignore any unknown fields that are silently dropped from the object, and will ignore all but the last duplicate field that the decoder encounters. This is the default behavior prior to v1.23. - Warn: This will send a warning via the standard warning response header for each unknown field that is dropped from the object, and for each duplicate field that is encountered. The request will still succeed if there are no other errors, and will only persist the last of any duplicate fields. This is the default in v1.23+ - Strict: This will fail the request with a BadRequest error if any unknown fields would be dropped from the object, or if any duplicate fields are present. The error returned from the server will contain all unknown and duplicate fields encountered. |
Parameter | Type | Description |
---|---|---|
|
|
HTTP code | Reponse body |
---|---|
200 - OK |
|
201 - Created |
|
202 - Accepted |
|
401 - Unauthorized | Empty |
17.2.4. /apis/apps/v1/watch/namespaces/{namespace}/statefulsets
- HTTP method
-
GET
- Description
- watch individual changes to a list of StatefulSet. deprecated: use the 'watch' parameter with a list operation instead.
HTTP code | Reponse body |
---|---|
200 - OK |
|
401 - Unauthorized | Empty |
17.2.5. /apis/apps/v1/namespaces/{namespace}/statefulsets/{name}
Parameter | Type | Description |
---|---|---|
|
| name of the StatefulSet |
- HTTP method
-
DELETE
- Description
- delete a StatefulSet
Parameter | Type | Description |
---|---|---|
|
| When present, indicates that modifications should not be persisted. An invalid or unrecognized dryRun directive will result in an error response and no further processing of the request. Valid values are: - All: all dry run stages will be processed |
HTTP code | Reponse body |
---|---|
200 - OK |
|
202 - Accepted |
|
401 - Unauthorized | Empty |
- HTTP method
-
GET
- Description
- read the specified StatefulSet
HTTP code | Reponse body |
---|---|
200 - OK |
|
401 - Unauthorized | Empty |
- HTTP method
-
PATCH
- Description
- partially update the specified StatefulSet
Parameter | Type | Description |
---|---|---|
|
| When present, indicates that modifications should not be persisted. An invalid or unrecognized dryRun directive will result in an error response and no further processing of the request. Valid values are: - All: all dry run stages will be processed |
|
| fieldValidation instructs the server on how to handle objects in the request (POST/PUT/PATCH) containing unknown or duplicate fields. Valid values are: - Ignore: This will ignore any unknown fields that are silently dropped from the object, and will ignore all but the last duplicate field that the decoder encounters. This is the default behavior prior to v1.23. - Warn: This will send a warning via the standard warning response header for each unknown field that is dropped from the object, and for each duplicate field that is encountered. The request will still succeed if there are no other errors, and will only persist the last of any duplicate fields. This is the default in v1.23+ - Strict: This will fail the request with a BadRequest error if any unknown fields would be dropped from the object, or if any duplicate fields are present. The error returned from the server will contain all unknown and duplicate fields encountered. |
HTTP code | Reponse body |
---|---|
200 - OK |
|
201 - Created |
|
401 - Unauthorized | Empty |
- HTTP method
-
PUT
- Description
- replace the specified StatefulSet
Parameter | Type | Description |
---|---|---|
|
| When present, indicates that modifications should not be persisted. An invalid or unrecognized dryRun directive will result in an error response and no further processing of the request. Valid values are: - All: all dry run stages will be processed |
|
| fieldValidation instructs the server on how to handle objects in the request (POST/PUT/PATCH) containing unknown or duplicate fields. Valid values are: - Ignore: This will ignore any unknown fields that are silently dropped from the object, and will ignore all but the last duplicate field that the decoder encounters. This is the default behavior prior to v1.23. - Warn: This will send a warning via the standard warning response header for each unknown field that is dropped from the object, and for each duplicate field that is encountered. The request will still succeed if there are no other errors, and will only persist the last of any duplicate fields. This is the default in v1.23+ - Strict: This will fail the request with a BadRequest error if any unknown fields would be dropped from the object, or if any duplicate fields are present. The error returned from the server will contain all unknown and duplicate fields encountered. |
Parameter | Type | Description |
---|---|---|
|
|
HTTP code | Reponse body |
---|---|
200 - OK |
|
201 - Created |
|
401 - Unauthorized | Empty |
17.2.6. /apis/apps/v1/watch/namespaces/{namespace}/statefulsets/{name}
Parameter | Type | Description |
---|---|---|
|
| name of the StatefulSet |
- HTTP method
-
GET
- Description
- watch changes to an object of kind StatefulSet. deprecated: use the 'watch' parameter with a list operation instead, filtered to a single item with the 'fieldSelector' parameter.
HTTP code | Reponse body |
---|---|
200 - OK |
|
401 - Unauthorized | Empty |
17.2.7. /apis/apps/v1/namespaces/{namespace}/statefulsets/{name}/status
Parameter | Type | Description |
---|---|---|
|
| name of the StatefulSet |
- HTTP method
-
GET
- Description
- read status of the specified StatefulSet
HTTP code | Reponse body |
---|---|
200 - OK |
|
401 - Unauthorized | Empty |
- HTTP method
-
PATCH
- Description
- partially update status of the specified StatefulSet
Parameter | Type | Description |
---|---|---|
|
| When present, indicates that modifications should not be persisted. An invalid or unrecognized dryRun directive will result in an error response and no further processing of the request. Valid values are: - All: all dry run stages will be processed |
|
| fieldValidation instructs the server on how to handle objects in the request (POST/PUT/PATCH) containing unknown or duplicate fields. Valid values are: - Ignore: This will ignore any unknown fields that are silently dropped from the object, and will ignore all but the last duplicate field that the decoder encounters. This is the default behavior prior to v1.23. - Warn: This will send a warning via the standard warning response header for each unknown field that is dropped from the object, and for each duplicate field that is encountered. The request will still succeed if there are no other errors, and will only persist the last of any duplicate fields. This is the default in v1.23+ - Strict: This will fail the request with a BadRequest error if any unknown fields would be dropped from the object, or if any duplicate fields are present. The error returned from the server will contain all unknown and duplicate fields encountered. |
HTTP code | Reponse body |
---|---|
200 - OK |
|
201 - Created |
|
401 - Unauthorized | Empty |
- HTTP method
-
PUT
- Description
- replace status of the specified StatefulSet
Parameter | Type | Description |
---|---|---|
|
| When present, indicates that modifications should not be persisted. An invalid or unrecognized dryRun directive will result in an error response and no further processing of the request. Valid values are: - All: all dry run stages will be processed |
|
| fieldValidation instructs the server on how to handle objects in the request (POST/PUT/PATCH) containing unknown or duplicate fields. Valid values are: - Ignore: This will ignore any unknown fields that are silently dropped from the object, and will ignore all but the last duplicate field that the decoder encounters. This is the default behavior prior to v1.23. - Warn: This will send a warning via the standard warning response header for each unknown field that is dropped from the object, and for each duplicate field that is encountered. The request will still succeed if there are no other errors, and will only persist the last of any duplicate fields. This is the default in v1.23+ - Strict: This will fail the request with a BadRequest error if any unknown fields would be dropped from the object, or if any duplicate fields are present. The error returned from the server will contain all unknown and duplicate fields encountered. |
Parameter | Type | Description |
---|---|---|
|
|
HTTP code | Reponse body |
---|---|
200 - OK |
|
201 - Created |
|
401 - Unauthorized | Empty |