使用动态客户端

问题描述

我关注了@ymmt2005 优秀的dynamic client guide。一切都很好，直到我进行实际 PATCH 调用的最后一步，并且出现 the server could not find the requested resource 错误。几乎一切似乎都正确，除了我不确定 PathOptions 结构中的“FieldManager”字段。我不确定“进行这些更改的参与者或实体”指的是什么。这是否需要匹配我的代码或系统中的某些内容？还有其他想法吗？

package main

import (
...
)

const resourceYAML = `
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mike-nginx
spec:
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
        - name: nginx
          image: 'nginx:latest'
          ports:
            - containerPort: 80
`

func main() {
    ctx := context.Background()

    // Create dynamic discovery client from local kubeconfig file
    kubePath := filepath.Join(homedir.HomeDir(),".kube","config")
    cfg,err := clientcmd.BuildConfigFromFlags("",kubePath)
    if err != nil {
        log.Fatalf("error building config,%v\n",err)
    }
    dynClient,err := dynamic.NewForConfig(cfg)
    if err != nil {
        log.Fatalf("error creating client,err)
    }
    disClient,err := discovery.NewDiscoveryClientForConfig(cfg)
    if err != nil {
        log.Fatalf("error creating discovery client,err)
    }

    // Decode YAML manifest & get GVK
    decodeUnstr := yaml.NewDecodingSerializer(unstructured.UnstructuredJSONScheme)
    obj := &unstructured.Unstructured{}
    _,gvk,err := decodeUnstr.Decode([]byte(resourceYAML),nil,obj)
    if err != nil {
        log.Fatalf("error decoding manifest,err)
    }
    jsonObj,err := json.Marshal(obj)
    if err != nil {
        log.Fatalf("error marshaling object,err)
    }

    // Find GVR using GVK
    mapper := restmapper.NewDeferredDiscoveryRESTMapper(memory.NewMemCacheClient(disClient))
    mapping,err := mapper.RESTMapping(gvk.GroupKind(),gvk.Version)
    if err != nil {
        log.Fatalf("error finding GVR,err)
    }

    // Get REST interface for the GVR,checking for namespace or cluster-wide
    var dr dynamic.ResourceInterface
    if mapping.Scope.Name() == meta.RESTScopeNameNamespace {
        // Namespaced resource
        dr = dynClient.Resource(mapping.Resource).Namespace(obj.GetNamespace())
    } else {
        // Cluster-wide resource
        dr = dynClient.Resource(mapping.Resource)
    }

    // Create or Update the object with SSA
    options := metav1.PatchOptions{FieldManager: "sample-controller"}
    _,err = dr.Patch(ctx,obj.GetName(),types.ApplyPatchType,jsonObj,options)
    if err != nil {
        log.Fatalf("error patching,err)
    }
}

[edit] 我确认我只能在已经存在的资源上使用“补丁”。我调整了代码以使用“创建”来创建资源，然后我能够成功地对其进行“修补”以进行更改。为了克服 FieldManager 的不一致，我在 PatchOptions 中添加了 Force=true ，无论如何在文档中推荐。我仍然想知道如何在资源不存在的情况下创建并在存在时进行更新——也许只是测试是否存在？

解决方法

答案很简单。原始代码假定清单中提供了 namespace。如果提供的命名空间是“”，部署端点不会自动将命名空间设置为 default，并且由于“”不是有效的命名空间而出错。因此，我添加了逻辑以将命名空间设置为 default 如果未提供并预先设置，如果资源不存在，服务器端应用将创建资源，如果存在则更新。再次感谢@ymmt2005。

package main

import (
...
)

const resourceYAML = `
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mike-nginx
spec:
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
        - name: nginx
          image: 'nginx:latest'
          ports:
            - containerPort: 80
`

func main() {
    ctx := context.Background()

    // Create dynamic discovery client from local kubeconfig file
    kubePath := filepath.Join(homedir.HomeDir(),".kube","config")
    cfg,err := clientcmd.BuildConfigFromFlags("",kubePath)
    if err != nil {
        log.Fatalf("error building config,%v\n",err)
    }
    dynClient,err := dynamic.NewForConfig(cfg)
    if err != nil {
        log.Fatalf("error creating client,err)
    }
    disClient,err := discovery.NewDiscoveryClientForConfig(cfg)
    if err != nil {
        log.Fatalf("error creating discovery client,err)
    }

    // Decode YAML manifest & get GVK
    decodeUnstr := yaml.NewDecodingSerializer(unstructured.UnstructuredJSONScheme)
    obj := &unstructured.Unstructured{}
    _,gvk,err := decodeUnstr.Decode([]byte(resourceYAML),nil,obj)
    if err != nil {
        log.Fatalf("error decoding manifest,err)
    }
    jsonObj,err := json.Marshal(obj)
    if err != nil {
        log.Fatalf("error marshaling object,err)
    }

    // Find GVR using GVK
    mapper := restmapper.NewDeferredDiscoveryRESTMapper(memory.NewMemCacheClient(disClient))
    mapping,err := mapper.RESTMapping(gvk.GroupKind(),gvk.Version)
    if err != nil {
        log.Fatalf("error finding GVR,err)
    }

    // Set Namespace to default if not provided in manifest
    var ns string
    if ns = obj.GetNamespace(); ns == "" {
        ns = "default"
    }

    // Get REST interface for the GVR,checking for namespace or cluster-wide
    var dr dynamic.ResourceInterface
    if mapping.Scope.Name() == meta.RESTScopeNameNamespace {
        // Namespaced resource
        dr = dynClient.Resource(mapping.Resource).Namespace(ns)
    } else {
        // Cluster-wide resource
        dr = dynClient.Resource(mapping.Resource)
    }

    // Create or Update the object with SSA
    options := metav1.PatchOptions{FieldManager: "sample-controller"}
    _,err = dr.Patch(ctx,obj.GetName(),types.ApplyPatchType,jsonObj,options)
    if err != nil {
        log.Fatalf("error patching,err)
    }
}