云原生学习路线导航页（持续更新中）
- 本文是 Kubernetes operator学习 系列第四篇，主要对 使用 controller-tools 进行 CRD 自动代码生成进行学习
- Kubernetes operator学习系列 快捷链接
- Kubernetes operator（一）client-go篇
- Kubernetes operator（二）CRD篇
- Kubernetes operator（三）code-generator 篇
- Kubernetes operator（四）controller-tools 篇
1.controller-tools 简介
1.1.code-generator自动生成代码存在的问题
- Kubernetes operator（三）code-generator 篇 中，我们提到，code-generator编写CRD控制器有两个问题：
- 问题一：需要手动编写CRD的yaml，无法自动生成
- 问题二：types.go文件全部内容都需要我们手写，无法自动生成框架
- 这部分工作量其实也是挺大的，kubernetes提供了一个工具 controller-tools，可以对这部分内容也进行代码自动生成
1.2.controller-tools是什么
1.2.1.kubernetes-sigs 项目是什么
- kubernetes-sigs 是一个由 Kubernetes 社区维护的 GitHub 组织，其中包含了许多与 Kubernetes 相关的项目，这些项目通常是为 Kubernetes 生态系统开发的，用于提供各种功能和工具。
- 一些 kubernetes-sigs 组织中的流行项目包括：
- kustomize：一种用于 Kubernetes 部署的配置管理工具，可以通过 YAML 声明文件对 Kubernetes 对象进行自定义，并且支持多环境部署（例如 dev、stage、prod）。
- kubebuilder：一种用于构建 Kubernetes API 的 SDK 工具，可以帮助开发者快速构建和测试 Kubernetes 的自定义控制器。
- cluster-api：一种 Kubernetes 的 API 扩展，用于管理 Kubernetes 集群的生命周期，包括创建、扩容和删除。它允许开发者使用 Kubernetes 的声明性 API 来管理整个集群的生命周期。
- kubefed：用于跨 Kubernetes 集群联邦的控制平面。它提供了一种将多个 Kubernetes 集群组合成一个统一的逻辑实体的方法，同时保持每个集群的独立性。
- controller-tools：用于简化 Kubernetes 控制器的开发，提供了一组工具来生成和更新 Kubernetes API 对象的代码，以及构建自定义控制器所需的代码框架。
1.2.2.controller-tools是什么
- controller-tools其实是一个由 Kubernetes 社区维护的项目，用于简化 Kubernetes 控制器的开发。其中提供了一组工具来生成和更新 Kubernetes API 对象的代码，以及构建自定义控制器所需的代码框架。
- controller-tools 的github地址：https://github.com/kubernetes-sigs/controller-tools
1.2.3.controller-tools 包含哪些工具
- 在controller-tools源码的cmd目录下，可以看到包含三个工具
- controller-gen：用于生成 zz_xxx.deepcopy.go 文件以及 crd 文件【kubebuilder也是通过这个工具生成crd的相关框架的】
- type-scaffold：用于生成所需的 types.go 文件
- helpgen：用于生成针对 Kubernetes API 对象的代码文档，可以包括 API 对象的字段、标签和注释等信息
2.controller-tools 使用过程
2.1.controller-tools 的 安装
- controller-tools 的 github 地址：https://github.com/kubernetes-sigs/controller-tools.git，克隆代码
git clone https://github.com/kubernetes-sigs/controller-tools.git- 将分支切换到 v0.9.0 的tag上
git checkout v0.9.0- 编译项目，安装代码生成工具，这里我们只安装需要的2个工具
- controller-gen工具：生成 deepcopy方法 文件 + crd 文件
- type-scaffold工具：生成 types.go 文件
cd controller-tools
# linux下安装，执行这一条即可
go install ./cmd/{controller-gen,type-scaffold}
# windows下安装，需要执行两条命令
go install ./cmd/controller-gen
go install ./cmd/type-scaffold- 查看安装结果
- Linux下，在 GOPATH 下的 bin 目录下，会出现我们安装的工具 controller-gen、type-scaffold
- Windows下，在GOPATH/bin/windows_amd64下，有这两个工具
- 检查环境变量设置是否成功（Linux）
- 打开终端，执行 type-scaffold --help，如果报错：
[root@master zgy]# type-scaffold --help
-bash: type-scaffold: 未找到命令- 说明环境变量没有设置成功，需要将 gopath/bin 加入PATH
vim ~/.bashrc
# 在~/.bashrc文件的末尾，加上这么一句
export PATH="$PATH:$GOPATH/bin"
# 然后，source一下
source ~/.bashrc- 再执行 type-scaffold --help，就成功了
[root@master zgy]# type-scaffold --help
Quickly scaffold out the structure of a type for a Kubernetes kind and associated types.
Produces:
- a root type with appropriate metadata fields
- Spec and Status types
- a list type
Also applies the appropriate comments to generate the code required to conform to runtime.Object.
Usage:
type-scaffold [flags]
Examples:
# Generate types for a Kind called Foo with a resource called foos
type-scaffold --kind Foo
# Generate types for a Kind called Bar with a resource of foobars
type-scaffold --kind Bar --resource foobars
Flags:
-h, --help help for type-scaffold
--kind string The kind of the typescaffold being scaffolded.
--namespaced Whether or not the given resource is namespaced. (default true)
--resource string The resource of the typescaffold being scaffolded (defaults to a lower-case, plural version of kind).2.2.type-scaffold 的使用方法
- type-scaffold 常用命令
type-scaffold --kind <Kind> [flags]
type-scaffold --help- --kind：参数用于指定要创建的资源类型（例如 Application）
2.3.controller-gen 的使用方法
- controller-gen 常用命令
# 生成 CRD 文件，并将生成的文件输出到 config/crds 目录中
controller-gen crd paths=./... output:crd:dir=config/crds
# 生成与对象相关的代码，通常是指生成控制器相关的代码模板
controller-gen object paths=./...3.controller-tools实战：自动生成代码
- 本项目已放入girhub代码仓库：https://github.com/graham924/share-code-operator-study
3.1.初始化项目
- 创建目录
- 初始化go项目，并get client-go
cd controller-tools-demo
go mod init controller-tools-demo
go get k8s.io/client-go
go get k8s.io/apimachinery3.2.使用type-scaffold工具生成types.go
- 需要注意：
- type-scaffold并不会生成文件，而是生成types.go的内容，打印到控制台，我们需要手动copy到types.go文件中去
- 不过使用kubebuilder的时候，会帮我们生成types.go文件的
- 执行 type-scaffold --kind=Application，得到types.go的内容
[root@master controller-tools-demo]# type-scaffold --kind=Application
// ApplicationSpec defines the desired state of Application
type ApplicationSpec struct {
// INSERT ADDITIONAL SPEC FIELDS -- desired state of cluster
}
// ApplicationStatus defines the observed state of Application.
// It should always be reconstructable from the state of the cluster and/or outside world.
type ApplicationStatus struct {
// INSERT ADDITIONAL STATUS FIELDS -- observed state of cluster
}
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
// Application is the Schema for the applications API
// +k8s:openapi-gen=true
type Application struct {
metav1.TypeMeta `json:",inline"`
metav1.ObjectMeta `json:"metadata,omitempty"`
Spec ApplicationSpec `json:"spec,omitempty"`
Status ApplicationStatus `json:"status,omitempty"`
}
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
// ApplicationList contains a list of Application
type ApplicationList struct {
metav1.TypeMeta `json:",inline"`
metav1.ListMeta `json:"metadata,omitempty"`
Items []Application `json:"items"`
}- 在 v1alpha1 目录下创建 types.go 文件，将控制台的内容copy进去，记得导包
package v1alpha1
import metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
// ApplicationSpec defines the desired state of Application
type ApplicationSpec struct {
// INSERT ADDITIONAL SPEC FIELDS -- desired state of cluster
}
// ApplicationStatus defines the observed state of Application.
// It should always be reconstructable from the state of the cluster and/or outside world.
type ApplicationStatus struct {
// INSERT ADDITIONAL STATUS FIELDS -- observed state of cluster
}
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
// Application is the Schema for the applications API
// +k8s:openapi-gen=true
type Application struct {
metav1.TypeMeta `json:",inline"`
metav1.ObjectMeta `json:"metadata,omitempty"`
Spec ApplicationSpec `json:"spec,omitempty"`
Status ApplicationStatus `json:"status,omitempty"`
}
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
// ApplicationList contains a list of Application
type ApplicationList struct {
metav1.TypeMeta `json:",inline"`
metav1.ListMeta `json:"metadata,omitempty"`
Items []Application `json:"items"`
}3.3.使用controller-gen生成deepcopy和crd文件
3.3.1.controller-gen --help 查看帮助文档
- 帮助文档给出了很多 examples
[root@master v1alpha1]# controller-gen --help
Generate Kubernetes API extension resources and code.
Usage:
controller-gen [flags]
Examples:
# Generate RBAC manifests and crds for all types under apis/,
# outputting crds to /tmp/crds and everything else to stdout
controller-gen rbac:roleName=<role name> crd paths=./apis/... output:crd:dir=/tmp/crds output:stdout
# Generate deepcopy/runtime.Object implementations for a particular file
controller-gen object paths=./apis/v1beta1/some_types.go
# Generate OpenAPI v3 schemas for API packages and merge them into existing CRD manifests
controller-gen schemapatch:manifests=./manifests output:dir=./manifests paths=./pkg/apis/...
# Run all the generators for a given project
controller-gen paths=./apis/...
# Explain the markers for generating CRDs, and their arguments
controller-gen crd -ww
Flags:
-h, --detailed-help count print out more detailed help
(up to -hhh for the most detailed output, or -hhhh for json output)
--help print out usage and a summary of options
--version show version
-w, --which-markers count print out all markers available with the requested generators
(up to -www for the most detailed output, or -wwww for json output)
Options
generators
+webhook package generates (partial) {Mutating,Validating}WebhookConfiguration objects.
+schemapatch[:generateEmbeddedObjectMeta=<bool>],manifests=<string>[,maxDescLen=<int>] package patches existing CRDs with new schemata.
+rbac:roleName=<string> package generates ClusterRole objects.
+object[:headerFile=<string>][,year=<string>] package generates code containing DeepCopy, DeepCopyInto, and DeepCopyObject method implementations.
+crd[:allowDangerousTypes=<bool>][,crdVersions=<[]string>][,generateEmbeddedObjectMeta=<bool>][,ignoreUnexportedFields=<bool>][,maxDescLen=<int>] package generates CustomResourceDefinition objects.
generic
+paths=<[]string> package represents paths and go-style path patterns to use as package roots.
output rules (optionally as output:<generator>:...)
+output:artifacts[:code=<string>],config=<string> package outputs artifacts to different locations, depending on whether they're package-associated or not.
+output:dir=<string> package outputs each artifact to the given directory, regardless of if it's package-associated or not.
+output:none package skips outputting anything.
+output:stdout package outputs everything to standard-out, with no separation.3.3.2.使用controller-gen生成deepcopy
- 先刷新一下包
go mod tidy- 执行命令
cd controller-tools-demo
controller-gen object paths=pkg/apis/appcontroller/v1alpha1/types.go- 执行后，查看目录文件，发现生成了一个 zz_generated.deepcopy.go 文件
[root@master controller-tools-demo]# tree
.
├── go.mod
├── go.sum
└── pkg
└── apis
└── appcontroller
└── v1alpha1
├── types.go
└── zz_generated.deepcopy.go- 查看 zz_generated.deepcopy.go 文件内容
//go:build !ignore_autogenerated
// +build !ignore_autogenerated
// Code generated by controller-gen. DO NOT EDIT.
package v1alpha1
import (
runtime "k8s.io/apimachinery/pkg/runtime"
)
// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
func (in *Application) DeepCopyInto(out *Application) {
*out = *in
out.TypeMeta = in.TypeMeta
in.ObjectMeta.DeepCopyInto(&out.ObjectMeta)
out.Spec = in.Spec
out.Status = in.Status
}
// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new Application.
func (in *Application) DeepCopy() *Application {
if in == nil {
return nil
}
out := new(Application)
in.DeepCopyInto(out)
return out
}
// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
func (in *Application) DeepCopyObject() runtime.Object {
if c := in.DeepCopy(); c != nil {
return c
}
return nil
}
// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
func (in *ApplicationList) DeepCopyInto(out *ApplicationList) {
*out = *in
out.TypeMeta = in.TypeMeta
in.ListMeta.DeepCopyInto(&out.ListMeta)
if in.Items != nil {
in, out := &in.Items, &out.Items
*out = make([]Application, len(*in))
for i := range *in {
(*in)[i].DeepCopyInto(&(*out)[i])
}
}
}
// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new ApplicationList.
func (in *ApplicationList) DeepCopy() *ApplicationList {
if in == nil {
return nil
}
out := new(ApplicationList)
in.DeepCopyInto(out)
return out
}
// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
func (in *ApplicationList) DeepCopyObject() runtime.Object {
if c := in.DeepCopy(); c != nil {
return c
}
return nil
}3.3.3.使用controller-gen生成crd
- 先刷新一下包
go mod tidy- 执行命令
cd controller-tools-demo
controller-gen crd paths=./... output:crd:dir=config/crd- paths=./... 表示将当前目录下的所有子目录都包括在生成过程中
- output:crd:dir=config/crd 指定了输出目录为 config/crd
- 执行后，生成目录 config 和 文件 _.yaml
[root@master controller-tools-demo]# tree
.
├── config
│ └── crd
│ └── _.yaml
├── go.mod
├── go.sum
└── pkg
└── apis
└── appcontroller
└── v1alpha1
├── types.go
└── zz_generated.deepcopy.go- 文件 _.yaml 没有名字？指定groupName后重新生成 crd 文件
- 因为我们没有给它指定 groupName，所以生成的yaml文件默认没有名字
- 我们在 pkg/apis/appcontroller/v1alpha1 下创建一个 doc.go 文件，并在里面写上如下内容
// +groupName=appcontroller.k8s.io
package v1alpha1- 然后删除原config后，重新生成crd
cd controller-tools-demo
rm -rf config
controller-gen crd paths=./... output:crd:dir=config/crd- 生成完成后，目录如下
- crd文件名称为：appcontroller.k8s.io_applications.yaml
[root@master controller-tools-demo]# tree
.
├── config
│ └── crd
│ └── appcontroller.k8s.io_applications.yaml
├── go.mod
├── go.sum
└── pkg
└── apis
└── appcontroller
└── v1alpha1
├── doc.go
├── types.go
└── zz_generated.deepcopy.go
6 directories, 6 files- appcontroller.k8s.io_applications.yaml 内容如下
- 可以看到，openAPIV3Schema.properties.spec 下面，没有 properties 项，因为我们的ApplicationSpec 为空，内部一个属性都没有。
---
apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
annotations:
controller-gen.kubebuilder.io/version: (devel)
creationTimestamp: null
name: applications.appcontroller.k8s.io
spec:
group: appcontroller.k8s.io
names:
kind: Application
listKind: ApplicationList
plural: applications
singular: application
scope: Namespaced
versions:
- name: v1alpha1
schema:
openAPIV3Schema:
description: Application is the Schema for the applications API
properties:
apiVersion:
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'
type: string
kind:
description: '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'
type: string
metadata:
type: object
spec:
description: ApplicationSpec defines the desired state of Application
type: object
status:
description: ApplicationStatus defines the observed state of Application.
It should always be reconstructable from the state of the cluster and/or
outside world.
type: object
type: object
served: true
storage: true3.4.为ApplicationSpec添加内容，并重新生成crd文件
- 修改types.go，在 ApplicationSpec 中添加两个字段
type ApplicationSpec struct {
// INSERT ADDITIONAL SPEC FIELDS -- desired state of cluster
Name string `json:"name"`
Replicas int32 `json:"replicas"`
}- 删除原config后，重新生成crd文件
cd controller-tools-demo
rm -rf config
controller-gen crd paths=./... output:crd:dir=config/crd- 新的crd文件内容如下：
- 可以看到，openAPIV3Schema.properties.spec 下面，出现了 properties 项，因为我们为ApplicationSpec 添加了Name、Replicas两个值。
---
apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
annotations:
controller-gen.kubebuilder.io/version: (devel)
creationTimestamp: null
name: applications.appcontroller.k8s.io
spec:
group: appcontroller.k8s.io
names:
kind: Application
listKind: ApplicationList
plural: applications
singular: application
scope: Namespaced
versions:
- name: v1alpha1
schema:
openAPIV3Schema:
description: Application is the Schema for the applications API
properties:
apiVersion:
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'
type: string
kind:
description: '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'
type: string
metadata:
type: object
spec:
description: ApplicationSpec defines the desired state of Application
properties:
name:
description: INSERT ADDITIONAL SPEC FIELDS -- desired state of cluster
type: string
replicas:
format: int32
type: integer
required:
- name
- replicas
type: object
status:
description: ApplicationStatus defines the observed state of Application.
It should always be reconstructable from the state of the cluster and/or
outside world.
type: object
type: object
served: true
storage: true3.5.手动注册版本v1alpha1的CRD资源
- 在生成了客户端代码后，我们还需要手动注册版本v1alpha1的CRD资源，才能真正使用这个client，不然在编译时会出现 undefined: v1alpha1.AddToScheme 错误、undefined: v1alpha1.Resource 错误。
- v1alpha1.AddToScheme、v1alpha1.Resource 这两个是用于 client 注册的
- 编写 v1alpha1/register.go
package v1alpha1
import (
"controller-tools-demo/pkg/apis/appcontroller"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
)
// SchemeGroupVersion is group version used to register these objects
var SchemeGroupVersion = schema.GroupVersion{Group: appcontroller.GroupName, Version: "v1alpha1"}
// Kind takes an unqualified kind and returns back a Group qualified GroupKind
func Kind(kind string) schema.GroupKind {
return SchemeGroupVersion.WithKind(kind).GroupKind()
}
// Resource takes an unqualified resource and returns a Group qualified GroupResource
func Resource(resource string) schema.GroupResource {
return SchemeGroupVersion.WithResource(resource).GroupResource()
}
var (
// SchemeBuilder initializes a scheme builder
SchemeBuilder = runtime.NewSchemeBuilder(addKnownTypes)
// AddToScheme is a global function that registers this API group & version to a scheme
AddToScheme = SchemeBuilder.AddToScheme
)
// Adds the list of known types to Scheme.
func addKnownTypes(scheme *runtime.Scheme) error {
scheme.AddKnownTypes(SchemeGroupVersion,
&Application{},
&ApplicationList{},
)
metav1.AddToGroupVersion(scheme, SchemeGroupVersion)
return nil
}3.6.在kubernetes集群中应用CRD
3.6.1.kubectl apply crd 资源
- 上面我们已经使用 controller-gen 自动生成了 CRD 文件，名称为 appcontroller.k8s.io_applications.yaml，再 config/crd 目录下
- 我们需要使用 kubectl apply 命令创建CR资源
cd controller-tools-demo
kubectl apply -f config/crd/appcontroller.k8s.io_applications.yaml- 有可能报错：
The CustomResourceDefinition "applications.appcontroller.k8s.io" is invalid: metadata.annotations[api-approved.kubernetes.io]: Required value: protected groups must have approval annotation "api-approved.kubernetes.io", see https://github.com/kubernetes/enhancements/pull/1111- 解决方法
- 这是kubernetes的保护机制，防止外部随意创建crd，破坏环境
- 报错中已经给了提示，查看github：https://github.com/kubernetes/enhancements/pull/1111
- 只需要在crd中，添加一条 annotation，然后再执行 kubectl apply -f 命令就可以了
metadata:
annotations:
api-approved.kubernetes.io: "https://github.com/kubernetes/kubernetes/pull/78458"- 添加之后，完整的 crd 文件内容如下：
---
apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
annotations:
controller-gen.kubebuilder.io/version: (devel)
api-approved.kubernetes.io: "https://github.com/kubernetes/kubernetes/pull/78458"
creationTimestamp: null
name: applications.appcontroller.k8s.io
spec:
group: appcontroller.k8s.io
names:
kind: Application
listKind: ApplicationList
plural: applications
singular: application
scope: Namespaced
versions:
- name: v1alpha1
schema:
openAPIV3Schema:
description: Application is the Schema for the applications API
properties:
apiVersion:
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'
type: string
kind:
description: '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'
type: string
metadata:
type: object
spec:
description: ApplicationSpec defines the desired state of Application
properties:
name:
description: INSERT ADDITIONAL SPEC FIELDS -- desired state of cluster
type: string
replicas:
format: int32
type: integer
required:
- name
- replicas
type: object
status:
description: ApplicationStatus defines the observed state of Application.
It should always be reconstructable from the state of the cluster and/or
outside world.
type: object
type: object
served: true
storage: true3.6.2.编写 crd 资源的 example
- 在 config 目录下，创建一个example目录，内部可以编写一些 application资源的yaml，用于测试Application资源的创建是否可以成功
- 在config/example目录下，编写一个test_app.yaml
apiVersion: appcontroller.k8s.io/v1alpha1
kind: Application
metadata:
name: testapp
namespace: tcs
spec:
name: testapp1
replicas: 2- 创建Application资源
cd controller-tools-demo
kubectl apply -f ./config/example/test_app.yaml3.7.测试Application资源的获取
- 在项目根目录下，创建一个cmd目录，里面创建一个main.go文件
- 下面我们演示如何使用 code-generator 为 Application 的 v1alpha1 生成的客户端 AppcontrollerV1alpha1Client
- 编写main.go
package main
import (
"context"
"controller-tools-demo/pkg/apis/appcontroller/v1alpha1"
"fmt"
"log"
"k8s.io/client-go/kubernetes/scheme"
"k8s.io/client-go/rest"
"k8s.io/client-go/tools/clientcmd"
)
func main() {
config, err := clientcmd.BuildConfigFromFlags("", clientcmd.RecommendedHomeFile)
if err != nil {
log.Fatalln(err)
}
config.APIPath = "/apis/"
config.GroupVersion = &v1alpha1.SchemeGroupVersion
config.NegotiatedSerializer = scheme.Codecs
client, err := rest.RESTClientFor(config)
if err != nil {
log.Fatalln(err)
}
app := v1alpha1.Application{}
err = client.Get().Namespace("tcs").Resource("applications").Name("testapp").Do(context.TODO()).Into(&app)
if err != nil {
log.Fatalln(err)
}
newObj := app.DeepCopy()
newObj.Spec.Name = "testapp2"
fmt.Println(app.Spec.Name)
fmt.Println(app.Spec.Replicas)
fmt.Println(newObj.Spec.Name)
}- 输出结果
[root@master controller-tools-demo]# go run cmd/main.go
testapp1
2
testapp2- 如果没有在kubernetes集群中 应用 CRD资源，直接执行上面的代码，会报错：找不到这个资源。因此一定要先执行 3.6 的步骤
go run cmd/main.go
2024/01/31 16:01:17 the server could not find the requested resource (get applications.appcontroller.k8s.io test_app)参考优质博客
- controller-tool的简单使用
- kubebuilder文档controller-gen
- kubebuilder文档generating-crd
- markers
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