我想解析 kubernetes 清单文件（json/yaml）并能够将它们转换为 k8s 结构（以便稍后操作它们）
我知道有 NewYAMLOrJSONDecoder().Decode() 函数（https://github.com/kubernetes/apimachinery/blob/master/pkg/util/yaml/decoder.go）来读取 json/yaml 文件，但是下一步是：如何将它们转换为 k8s 结构/类型？
即，如果我读取带有命名空间对象的 yaml 文件，例如如何将其转换为 core/v1/namespace 接口
问候，
谢谢svenwltr，我不知道我们可以这样做。
同时，我设法找到了一种不同的方法，而不是更好的方法：
package main
import (
"flag"
"fmt"
"os"
"io"
"path/filepath"
"log"
"encoding/json"
//"time"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/tools/clientcmd"
"k8s.io/client-go/discovery"
"k8s.io/client-go/dynamic"
"k8s.io/apimachinery/pkg/util/yaml"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/apimachinery/pkg/api/meta"
"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
)
func main() {
var kubeconfig *string
if home := homeDir(); home != "" {
kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")
} else {
kubeconfig = flag.String("kubeconfig", "", "absolute path to the kubeconfig file")
}
flag.Parse()
// use the current context in kubeconfig
config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
if err != nil {
panic(err.Error())
}
// create the clientset
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
panic(err.Error())
}
f,err := os.Open("namespace.yaml")
if err!=nil {
log.Fatal(err)
}
d := yaml.NewYAMLOrJSONDecoder(f,4096)
dd := clientset.Discovery()
apigroups,err := discovery.GetAPIGroupResources(dd)
if err != nil {
log.Fatal(err)
}
restmapper := discovery.NewRESTMapper(apigroups,meta.InterfacesForUnstructured)
for {
// https://github.com/kubernetes/apimachinery/blob/master/pkg/runtime/types.go
ext := runtime.RawExtension{}
if err := d.Decode(&ext); err!=nil {
if err == io.EOF {
break
}
log.Fatal(err)
}
fmt.Println("raw: ",string(ext.Raw))
versions := &runtime.VersionedObjects{}
//_, gvk, err := objectdecoder.Decode(ext.Raw,nil,versions)
obj, gvk, err := unstructured.UnstructuredJSONScheme.Decode(ext.Raw,nil,versions)
fmt.Println("obj: ",obj)
// https://github.com/kubernetes/apimachinery/blob/master/pkg/api/meta/interfaces.go
mapping, err := restmapper.RESTMapping(gvk.GroupKind(), gvk.Version)
if err != nil {
log.Fatal(err)
}
restconfig := config
restconfig.GroupVersion = &schema.GroupVersion {
Group: mapping.GroupVersionKind.Group,
Version: mapping.GroupVersionKind.Version,
}
dclient,err := dynamic.NewClient(restconfig)
if err != nil {
log.Fatal(err)
}
// https://github.com/kubernetes/client-go/blob/master/discovery/discovery_client.go
apiresourcelist, err := dd.ServerResources()
if err != nil {
log.Fatal(err)
}
var myapiresource metav1.APIResource
for _,apiresourcegroup := range(apiresourcelist) {
if apiresourcegroup.GroupVersion == mapping.GroupVersionKind.Version {
for _,apiresource := range(apiresourcegroup.APIResources) {
//fmt.Println(apiresource)
if apiresource.Name == mapping.Resource && apiresource.Kind == mapping.GroupVersionKind.Kind {
myapiresource = apiresource
}
}
}
}
fmt.Println(myapiresource)
// https://github.com/kubernetes/client-go/blob/master/dynamic/client.go
var unstruct unstructured.Unstructured
unstruct.Object = make(map[string]interface{})
var blob interface{}
if err := json.Unmarshal(ext.Raw,&blob); err != nil {
log.Fatal(err)
}
unstruct.Object = blob.(map[string]interface{})
fmt.Println("unstruct:",unstruct)
ns := "default"
if md,ok := unstruct.Object["metadata"]; ok {
metadata := md.(map[string]interface{})
if internalns,ok := metadata["namespace"]; ok {
ns = internalns.(string)
}
}
res := dclient.Resource(&myapiresource,ns)
fmt.Println(res)
us,err := res.Create(&unstruct)
if err != nil {
log.Fatal(err)
}
fmt.Println("unstruct response:",us)
}
}
func homeDir() string {
if h := os.Getenv("HOME"); h != "" {
return h
}
return os.Getenv("USERPROFILE") // windows
}
import (
v1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/serializer"
"k8s.io/client-go/kubernetes/scheme"
)
func decode(data []byte) (*v1.Namespace, error) {
decoder := serializer.NewCodecFactory(scheme.Scheme).UniversalDecoder()
object := &v1.Namespace{}
err := runtime.DecodeInto(decoder, data, object)
if err != nil {
return nil, err
}
return object, nil
}
如果需要，SchemeGroupVersion为您的 CRD 调用生成的通行证。UniversalDecoder
使用runtime.Decode而不是runtime.DecodeInto解码未指定的对象类型。
这个问题与How to deserialize Kubernetes YAML file非常相似，但是这个问题有点过时了，因为包名发生了变化。
它也不直接使用 go 客户端，这意味着可能有另一种解决方案。
这是一个例子：
package main
import (
"fmt"
"k8s.io/kubernetes/pkg/api"
_ "k8s.io/kubernetes/pkg/api/install"
_ "k8s.io/kubernetes/pkg/apis/extensions/install"
"k8s.io/kubernetes/pkg/apis/extensions/v1beta1"
)
var json = `
{
"apiVersion": "extensions/v1beta1",
"kind": "Deployment",
"metadata": null,
"name": "my-nginx",
"replicas": 2,
"spec": null,
"template": {
"metadata": {
"labels": {
"run": "my-nginx"
}
},
"spec": {
"containers": [
{
"image": "nginx",
"name": "my-nginx",
"ports": [
{
"containerPort": 80
}
]
}
]
}
}
}
`
func main() {
// decode := api.Codecs.UniversalDecoder().Decode
decode := api.Codecs.UniversalDeserializer().Decode
obj, _, err := decode([]byte(json), nil, nil)
if err != nil {
fmt.Printf("%#v", err)
}
deployment := obj.(*v1beta1.Deployment)
fmt.Printf("%#v\n", deployment)
}
笔记
.../install可以解码的类型UniversalDecoder不知道和之间的区别在UniversalDeserializer哪里