简短的插曲：这些其他东西是什么？

如果你查看了 api/v1/ 目录中的其他文件，可能会注意到除了 cronjob_types.go 之外还有两个额外的文件：groupversion_info.go 和 zz_generated.deepcopy.go。

这两个文件都不需要编辑（前者保持不变，后者是自动生成的），但了解它们的内容是很有用的。

`groupversion_info.go`

groupversion_info.go 包含有关组版本的常见元数据：

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First, we have some package-level markers that denote that there are Kubernetes objects in this package, and that this package represents the group batch.tutorial.kubebuilder.io. The object generator makes use of the former, while the latter is used by the CRD generator to generate the right metadata for the CRDs it creates from this package.

// Package v1 contains API Schema definitions for the batch v1 API group.
// +kubebuilder:object:generate=true
// +groupName=batch.tutorial.kubebuilder.io
package v1

import (
	"k8s.io/apimachinery/pkg/runtime/schema"
	"sigs.k8s.io/controller-runtime/pkg/scheme"
)

Then, we have the commonly useful variables that help us set up our Scheme. Since we need to use all the types in this package in our controller, it’s helpful (and the convention) to have a convenient method to add all the types to some other Scheme. SchemeBuilder makes this easy for us.

var (
	// GroupVersion is group version used to register these objects.
	GroupVersion = schema.GroupVersion{Group: "batch.tutorial.kubebuilder.io", Version: "v1"}

	// SchemeBuilder is used to add go types to the GroupVersionKind scheme.
	SchemeBuilder = &scheme.Builder{GroupVersion: GroupVersion}

	// AddToScheme adds the types in this group-version to the given scheme.
	AddToScheme = SchemeBuilder.AddToScheme
)

`zz_generated.deepcopy.go`

zz_generated.deepcopy.go 包含了上述 runtime.Object 接口的自动生成实现，它将我们的所有根类型标记为表示种类（Kinds）。

runtime.Object 接口的核心是一个深拷贝方法 DeepCopyObject。

controller-tools中的object生成器还为每个根类型及其所有子类型生成了两个其他实用方法：DeepCopy和DeepCopyInto。