ReplicaSet

ReplicaSet ensures that a specified number of pod replicas are running at any given time.

Concept documentation for ReplicaSet

ReplicaSet

A ReplicaSet's purpose is to maintain a stable set of replica Pods running at any given time. Usually, you define a Deployment and let that Deployment manage ReplicaSets automatically.

apiVersion: apps/v1

import "k8s.io/api/apps/v1"

ReplicaSet ensures that a specified number of pod replicas are running at any given time.

Field	Description
`apiVersion` string	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` string	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
`metadata` ObjectMeta	If the Labels of a ReplicaSet are empty, they are defaulted to be the same as the Pod(s) that the ReplicaSet manages. Standard object's metadata. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
`spec` ReplicaSetSpec	Spec defines the specification of the desired behavior of the ReplicaSet. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
`status` ReplicaSetStatus	Status is the most recently observed status of the ReplicaSet. This data may be out of date by some window of time. Populated by the system. Read-only. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status

ReplicaSetSpec

ReplicaSetSpec is the specification of a ReplicaSet.

Field	Description
`minReadySeconds` integer	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)
`replicas` integer	Replicas is the number of desired pods. This is a pointer to distinguish between explicit zero and unspecified. Defaults to 1. More info: https://kubernetes.io/docs/concepts/workloads/controllers/replicaset
`selector` * LabelSelector	Selector is a label query over pods that should match the replica count. Label keys and values that must match in order to be controlled by this replica set. It must match the pod template's labels. More info: https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#label-selectors
`template` PodTemplateSpec	Template is the object that describes the pod that will be created if insufficient replicas are detected. More info: https://kubernetes.io/docs/concepts/workloads/controllers/replicaset/#pod-template

ReplicaSetStatus represents the current status of a ReplicaSet.

Field	Description
`availableReplicas` integer	The number of available non-terminating pods (ready for at least minReadySeconds) for this replica set.
`conditions` ReplicaSetCondition array patch strategy: merge on key `type`	Represents the latest available observations of a replica set's current state.
`fullyLabeledReplicas` integer	The number of non-terminating pods that have labels matching the labels of the pod template of the replicaset.
`observedGeneration` integer	ObservedGeneration reflects the generation of the most recently observed ReplicaSet.
`readyReplicas` integer	The number of non-terminating pods targeted by this ReplicaSet with a Ready Condition.
`replicas` * integer	Replicas is the most recently observed number of non-terminating pods. More info: https://kubernetes.io/docs/concepts/workloads/controllers/replicaset
`terminatingReplicas` integer	The number of terminating pods for this replica set. Terminating pods have a non-null .metadata.deletionTimestamp and have not yet reached the Failed or Succeeded .status.phase. This is a beta field and requires enabling DeploymentReplicaSetTerminatingReplicas feature (enabled by default).

ReplicaSetList is a collection of ReplicaSets.

Field	Description
`apiVersion` string	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
`items` * ReplicaSet array	List of ReplicaSets. More info: https://kubernetes.io/docs/concepts/workloads/controllers/replicaset
`kind` string	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
`metadata` ListMeta	Standard list metadata. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds

ReplicaSetCondition describes the state of a replica set at a certain point.

Field	Description
`lastTransitionTime` Time	The last time the condition transitioned from one status to another.
`message` string	A human readable message indicating details about the transition.
`reason` string	The reason for the condition's last transition.
`status` * string	Status of the condition, one of True, False, Unknown.
`type` * string	Type of replica set condition.

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https://kubernetes.io/docs/reference/kubernetes-api/apps/replica-set-v1/