Source: 概述

Wed, 14 May 2025 00:00:00 +0000

介绍

apps API 的核心功能是提供对应用层工作负载的声明式管理，主要包括：

部署管理：滚动更新、回滚、扩缩容
状态维护：确保应用实例数与声明的一致
版本控制：管理应用更新时的版本切换
与底层资源（Pod）的协调

主要管理的资源类型：

无状态应用（Deployment）
有状态应用（StatefulSet）
守护进程（DaemonSet）
一次性任务（ReplicaSet，通常由 Deployment 自动管理）

核心 API 资源类型

在 apps/v1 中定义了以下关键资源（所有资源均为 namespace-scoped）：

Deployment
DaemonSet
StatefulSet
ReplicaSet

源码学习路径

类型定义：

staging/src/k8s.io/api/apps/v1/types.go

控制器实现：

Deployment: pkg/controller/deployment/
StatefulSet: pkg/controller/statefulset/
DaemonSet: pkg/controller/daemon/

客户端操作：

staging/src/k8s.io/client-go/kubernetes/typed/apps/v1/

设计意义

抽象与自动化：将 Pod 管理从手动操作转为声明式管理
版本化运维：支持灰度发布、金丝雀发布等高级部署模式
状态分离：区分应用定义（Spec）和运行时状态（Status）

Source: types.go

Wed, 14 May 2025 00:00:00 +0000

StatefulSet

// 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 StatefulSet struct {
	metav1.TypeMeta `json:",inline"`
	// Standard object's metadata.
	// More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
	// +optional
	metav1.ObjectMeta `json:"metadata,omitempty" protobuf:"bytes,1,opt,name=metadata"`

	// Spec defines the desired identities of pods in this set.
	// +optional
	Spec StatefulSetSpec `json:"spec,omitempty" protobuf:"bytes,2,opt,name=spec"`

	// Status is the current status of Pods in this StatefulSet. This data
	// may be out of date by some window of time.
	// +optional
	Status StatefulSetStatus `json:"status,omitempty" protobuf:"bytes,3,opt,name=status"`
}

Deployment

// Deployment enables declarative updates for Pods and ReplicaSets.
type Deployment struct {
	metav1.TypeMeta `json:",inline"`
	// Standard object's metadata.
	// More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
	// +optional
	metav1.ObjectMeta `json:"metadata,omitempty" protobuf:"bytes,1,opt,name=metadata"`

	// Specification of the desired behavior of the Deployment.
	// +optional
	Spec DeploymentSpec `json:"spec,omitempty" protobuf:"bytes,2,opt,name=spec"`

	// Most recently observed status of the Deployment.
	// +optional
	Status DeploymentStatus `json:"status,omitempty" protobuf:"bytes,3,opt,name=status"`
}

DaemonSet

// DaemonSet represents the configuration of a daemon set.
type DaemonSet struct {
	metav1.TypeMeta `json:",inline"`
	// Standard object's metadata.
	// More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
	// +optional
	metav1.ObjectMeta `json:"metadata,omitempty" protobuf:"bytes,1,opt,name=metadata"`

	// The desired behavior of this daemon set.
	// More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
	// +optional
	Spec DaemonSetSpec `json:"spec,omitempty" protobuf:"bytes,2,opt,name=spec"`

	// The current status of this daemon set. 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
	// +optional
	Status DaemonSetStatus `json:"status,omitempty" protobuf:"bytes,3,opt,name=status"`
}

ReplicaSet

// ReplicaSet ensures that a specified number of pod replicas are running at any given time.
type ReplicaSet struct {
	metav1.TypeMeta `json:",inline"`

	// 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
	// +optional
	metav1.ObjectMeta `json:"metadata,omitempty" protobuf:"bytes,1,opt,name=metadata"`

	// 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
	// +optional
	Spec ReplicaSetSpec `json:"spec,omitempty" protobuf:"bytes,2,opt,name=spec"`

	// 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
	// +optional
	Status ReplicaSetStatus `json:"status,omitempty" protobuf:"bytes,3,opt,name=status"`
}

ControllerRevision


// ControllerRevision implements an immutable snapshot of state data. Clients
// are responsible for serializing and deserializing the objects that contain
// their internal state.
// Once a ControllerRevision has been successfully created, it can not be updated.
// The API Server will fail validation of all requests that attempt to mutate
// the Data field. ControllerRevisions may, however, be deleted. Note that, due to its use by both
// the DaemonSet and StatefulSet controllers for update and rollback, this object is beta. However,
// it may be subject to name and representation changes in future releases, and clients should not
// depend on its stability. It is primarily for internal use by controllers.
type ControllerRevision struct {
	metav1.TypeMeta `json:",inline"`
	// Standard object's metadata.
	// More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
	// +optional
	metav1.ObjectMeta `json:"metadata,omitempty" protobuf:"bytes,1,opt,name=metadata"`

	// Data is the serialized representation of the state.
	Data runtime.RawExtension `json:"data,omitempty" protobuf:"bytes,2,opt,name=data"`

	// Revision indicates the revision of the state represented by Data.
	Revision int64 `json:"revision" protobuf:"varint,3,opt,name=revision"`
}

Source: register.go

Wed, 14 May 2025 00:00:00 +0000

注册类型：

func addKnownTypes(scheme *runtime.Scheme) error {
	scheme.AddKnownTypes(SchemeGroupVersion,
		&Deployment{},
		&DeploymentList{},
		&StatefulSet{},
		&StatefulSetList{},
		&DaemonSet{},
		&DaemonSetList{},
		&ReplicaSet{},
		&ReplicaSetList{},
		&ControllerRevision{},
		&ControllerRevisionList{},
	)
	metav1.AddToGroupVersion(scheme, SchemeGroupVersion)
	return nil
}

Kubernetes学习笔记 – apps

Source: 概述

介绍

核心 API 资源类型

源码学习路径

设计意义

Source: types.go

StatefulSet

Deployment

DaemonSet

ReplicaSet

ControllerRevision

Source: register.go