自动生成代码controller tool的简单使用

$ git clone https://github.com/kubernetes-sigs/controller-tools.git

$ cd controller-gen
$ go install ./cmd/{controller-gen,type-scaffold}

$ mkdir controller-test && cd controller-test
$ go mod init controller-test
$ mkdir -p pkg/apis/example.com/v1
$ tree
.
├── go.mod
└── pkg
    └── apis
        └── example.com
            └── v1
4 directories, 1 file

$ type-scaffold --kind Foo
// FooSpec defines the desired state of Foo
type FooSpec struct {
        // INSERT ADDITIONAL SPEC FIELDS -- desired state of cluster
}
// FooStatus defines the observed state of Foo.
// It should always be reconstructable from the state of the cluster and/or outside world.
type FooStatus struct {
        // INSERT ADDITIONAL STATUS FIELDS -- observed state of cluster
}
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
// Foo is the Schema for the foos API
// +k8s:openapi-gen=true
type Foo struct {
        metav1.TypeMeta   `json:",inline"`
        metav1.ObjectMeta `json:"metadata,omitempty"`
        Spec   FooSpec   `json:"spec,omitempty"`
        Status FooStatus `json:"status,omitempty"`
}
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
// FooList contains a list of Foo
type FooList struct {
        metav1.TypeMeta `json:",inline"`
        metav1.ListMeta `json:"metadata,omitempty"`
        Items           []Foo `json:"items"`
}

// register.go
// +groupName=example.com
package v1
import (
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
	"k8s.io/apimachinery/pkg/runtime/serializer"
)
var (
	Scheme       = runtime.NewScheme()
	GroupVersion = schema.GroupVersion{
		Group:   "example.com",
		Version: "v1",
	}
	Codec = serializer.NewCodecFactory(Scheme)
)

// types.go
package v1
import metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
// FooSpec defines the desired state of Foo
type FooSpec struct {
	// INSERT ADDITIONAL SPEC FIELDS -- desired state of cluster
	Name     string `json:"name"`
	Replicas int32  `json:"replicas"`
}
// FooStatus defines the observed state of Foo.
// It should always be reconstructable from the state of the cluster and/or outside world.
type FooStatus struct {
	// INSERT ADDITIONAL STATUS FIELDS -- observed state of cluster
}
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
// Foo is the Schema for the foos API
// +k8s:openapi-gen=true
type Foo struct {
	metav1.TypeMeta   `json:",inline"`
	metav1.ObjectMeta `json:"metadata,omitempty"`
	Spec   FooSpec   `json:"spec,omitempty"`
	Status FooStatus `json:"status,omitempty"`
}
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
// FooList contains a list of Foo
type FooList struct {
	metav1.TypeMeta `json:",inline"`
	metav1.ListMeta `json:"metadata,omitempty"`
	Items           []Foo `json:"items"`
}
func init() {
	Scheme.AddKnownTypes(GroupVersion, &Foo{}, &FooList{})
}

$ controller-gen object paths=./pkg/apis/example.com/v1/types.go

$ mkdir config
$ go mod tidy
$ controller-gen crd paths=./... output:crd:dir=config/crd

.
├── config
│   └── crd
│       └── example.com_foos.yaml
├── go.mod
├── go.sum
└── pkg
    └── apis
        └── example.com
            └── v1
                ├── register.go
                ├── types.go
                └── zz_generated.deepcopy.go
6 directories, 6 files

apiVersion: example.com/v1
kind: Foo
metadata:
  name: crd-test
spec:
  name: test
  replicas: 2

package main
import (
	"context"
	v1 "controller-test/pkg/apis/example.com/v1"
	"fmt"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/clientcmd"
	"log"
)
func main() {
	config, err := clientcmd.BuildConfigFromFlags("", clientcmd.RecommendedHomeFile)
	if err != nil {
		log.Fatalln(err)
	}
	// 这边需要使用原始的 RESTClient
	config.APIPath = "/apis/"
	config.NegotiatedSerializer = v1.Codec
	config.GroupVersion = &v1.GroupVersion
	client, err := rest.RESTClientFor(config)
	if err != nil {
		log.Fatalln(err)
	}
	foo := &v1.Foo{}
	err = client.Get().Namespace("default").Resource("foos").Name("crd-test").Do(context.TODO()).Into(foo)
	if err != nil {
		log.Fatalln(err)
	}
	newObj := foo.DeepCopy()
	newObj.Spec.Name = "test2"
	fmt.Println(foo.Spec.Name)
	fmt.Println(newObj.Spec.Name)
}
//=======
// 输出结果
test
test2