从0开始详细介绍如何利用code-generator等工具构建CustomResource
- 下载k8s源码(code-generator,kubernetes等)代码
- 设置GOPATH
- 创建测试目录testcontroller,并构建以下目录树
wwh@wwh:~/kiongf/go/src/k8s1.9/src/testcontroller$ tree
.
└── pkg
└── apis
- 在apis中创建api组目录树, 示例中api组是xfleet/v1,可根据实际项目定义api组
wwh@wwh:~/kiongf/go/src/k8s1.9/src/testcontroller/pkg/apis$ tree
.
└── xfleet.com
├── register.go
└── v1
├── register.go //必须,否则无法注册api组
└── types.go
└── doc.go //必须,否则无法通过deepcopy-gen生成deepcopy
xfleet.com/v1/doc.go示例如下. 用于告知deepcopy-gen生成deepcopy文件. doc.go必须创建,而且不能删掉其中的注释.
// +k8s:deepcopy-gen=package,register
// Package v1 is the v1 version of the API.
// +groupName=xfleet.com
package v1xfleet.com/register.go示例如下. 用于注册api组
package xfleetcom
const (
GroupName = "xfleet.com"
)
xfleet.com/v1/register.go示例如下,用于注册api组版本
package v1
import (
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
examplecom "testcontroller/pkg/apis/xfleet.com"
)
// SchemeGroupVersion is group version used to register these objects
var SchemeGroupVersion = schema.GroupVersion{Group: examplecom.GroupName, Version: "v1"}
// Resource takes an unqualified resource and returns a Group qualified GroupResource
func Resource(resource string) schema.GroupResource {
return SchemeGroupVersion.WithResource(resource).GroupResource()
}
var (
// localSchemeBuilder and AddToScheme will stay in k8s.io/kubernetes.
SchemeBuilder runtime.SchemeBuilder
localSchemeBuilder = &SchemeBuilder
AddToScheme = localSchemeBuilder.AddToScheme
)
func init() {
// We only register manually written functions here. The registration of the
// generated functions takes place in the generated files. The separation
// makes the code compile even when the generated files are missing.
localSchemeBuilder.Register(addKnownTypes)
}
// Adds the list of known types to api.Scheme.
func addKnownTypes(scheme *runtime.Scheme) error {
scheme.AddKnownTypes(SchemeGroupVersion,
&Foo{},
&FooList{},
)
metav1.AddToGroupVersion(scheme, SchemeGroupVersion)
return nil
}
- 在v1目录中type.go文件,描述第三方资源的定义.示例如下
package v1
import (
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)
// +genclient
// +genclient:noStatus
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
// Foo is a specification for a Foo resource
type Foo struct {
metav1.TypeMeta `json:",inline"`
metav1.ObjectMeta `json:"metadata,omitempty"`
Spec FooSpec `json:"spec"`
Status FooStatus `json:"status"`
}
// FooSpec is the spec for a Foo resource
type FooSpec struct {
DeploymentName string `json:"deploymentName"`
Replicas *int32 `json:"replicas"`
Test bool `json:"test"`
}
// FooStatus is the status for a Foo resource
type FooStatus struct {
AvailableReplicas int32 `json:"availableReplicas"`
}
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
// FooList is a list of Foo resources
type FooList struct {
metav1.TypeMeta `json:",inline"`
metav1.ListMeta `json:"metadata"`
Items []Foo `json:"items"`
}
- 返回到$GOPATH/src目录
- 执行以下命令
k8s.io/code-generator/generate-groups.sh all testcontroller/pkg/client testcontroller/pkg/apis xfleet.com:v1- k8s.io/code-generator/generate-groups.sh: 执行的脚本
- all: 表示构建的目标,all包括clientset, informer, doc等
- testcontroller/pkg/client: 生成clientset,informer,doc存放的目录.这是相对路径, 根路径是是$GOPATH/src.可以通过在最后添加--output-base改变根路径.
- testcontroller/pkg/apis: api组资源定义路径.里面可能包括api组.
- xfleet:v1 : api组.
- 命令执行后,生成依赖目录树
testcontroller/
├── main.go
└── pkg
├── apis
│ └── xfleet.com
│ ├── register.go
│ └── v1
│ ├── doc.go
│ ├── register.go
│ ├── types.go
│ └── zz_generated.deepcopy.go
└── client
├── clientset
│ └── versioned
│ ├── clientset.go
│ ├── doc.go
│ ├── fake
│ │ ├── clientset_generated.go
│ │ ├── doc.go
│ │ └── register.go
│ ├── scheme
│ │ ├── doc.go
│ │ └── register.go
│ └── typed
│ └── xfleet.com
│ └── v1
│ ├── doc.go
│ ├── fake
│ │ ├── doc.go
│ │ ├── fake_foo.go
│ │ └── fake_xfleet.com_client.go
│ ├── foo.go
│ ├── generated_expansion.go
│ └── xfleet.com_client.go
├── informers
│ └── externalversions
│ ├── factory.go
│ ├── generic.go
│ ├── internalinterfaces
│ │ └── factory_interfaces.go
│ └── xfleet.com
│ ├── interface.go
│ └── v1
│ ├── foo.go
│ └── interface.go
└── listers
└── xfleet.com
└── v1
├── expansion_generated.go
└── foo.go
- 添加测试, 在testcontroller目录下创建main.go
package main
import (
"flag"
"fmt"
"github.com/golang/glog"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/client-go/tools/clientcmd"
examplecomclientset "testcontroller/pkg/client/clientset/versioned"
)
var (
kuberconfig = flag.String("kubeconfig", "", "Path to a kubeconfig. Only required if out-of-cluster.")
master = flag.String("master", "", "The address of the Kubernetes API server. Overrides any value in kubeconfig. Only required if out-of-cluster.")
)
func main() {
flag.Parse()
cfg, err := clientcmd.BuildConfigFromFlags(*master, *kuberconfig)
if err != nil {
glog.Fatalf("Error building kubeconfig: %v", err)
}
exampleClient, err := examplecomclientset.NewForConfig(cfg)
if err != nil {
glog.Fatalf("Error building example clientset: %v", err)
}
list, err := exampleClient.XfleetV1().Foos("default").List(metav1.ListOptions{})
if err != nil {
glog.Fatalf("Error listing all foos: %v", err)
}
for _, db := range list.Items {
fmt.Printf("database %s with user %q\n", db.Name, db.Spec.DeploymentName)
}
}
- 这时候,还不能直接调用.因为资源定义还没有注册到k8s中.直接调用会报
Error listing all foos: the server could not find the requested resource (get foos.xfleet.com)
- 这时候得创建一个crd,注册资源
package crd
import (
"reflect"
apiextv1beta1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
apiextcs "k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset"
apierrors "k8s.io/apimachinery/pkg/api/errors"
meta_v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
xfleetv1 "testcontroller/pkg/apis/xfleet.com/v1"
)
const (
CRDPlural string = "foos" //k8s如何描述资源,kubect get foos可以获取资源
CRDGroup string = "xfleet.com"
CRDVersion string = "v1"
FullCRDName string = CRDPlural + "." + CRDGroup
)
// Create the CRD resource, ignore error if it already exists
func CreateCRD(clientset apiextcs.Interface) error {
crd := &apiextv1beta1.CustomResourceDefinition{
ObjectMeta: meta_v1.ObjectMeta{Name: FullCRDName},
Spec: apiextv1beta1.CustomResourceDefinitionSpec{
Group: CRDGroup,
Version: CRDVersion,
Scope: apiextv1beta1.NamespaceScoped,
Names: apiextv1beta1.CustomResourceDefinitionNames{
Plural: CRDPlural,
Kind: reflect.TypeOf(xfleetv1.Foo{}).Name(), //资源类型
},
},
}
_, err := clientset.ApiextensionsV1beta1().CustomResourceDefinitions().Create(crd)
if err != nil && apierrors.IsAlreadyExists(err) {
return nil
}
return err
// Note the original apiextensions example adds logic to wait for creation and exception handling
}
- 在main函数中调用,创建crd
apix "k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset"
)
var (
kuberconfig = flag.String("kubeconfig", "", "Path to a kubeconfig. Only required if out-of-cluster.")
master = flag.String("master", "", "The address of the Kubernetes API server. Overrides any value in kubeconfig. Only required if out-of-cluster.")
)
func main() {
flag.Parse()
cfg, err := clientcmd.BuildConfigFromFlags(*master, *kuberconfig)
if err != nil {
glog.Fatalf("Error building kubeconfig: %v", err)
}
clientset, err := apix.NewForConfig(cfg)
if err != nil {
panic(err)
}
err = crd.CreateCRD(clientset)
if err != nil {
panic(err)
}
- 编译后执行
root@m-bang-192-168-9-203:~# kubectl get crd
NAME AGE
foos.xfleet.com 11s
root@m-bang-192-168-9-203:~# kubectl get foo
No resources found.
- https://github.com/yaronha/kube-crd 但注意,这个项目的作者并没有用code-generator生成clientset,而是通过代码写了一个
- https://thenewstack.io/extend-kubernetes-1-7-custom-resources