使用 client-go API 列出由部署 controller 管理的 pod 不起作用

Question

我在 Go 中使用本机客户端 API 来获取由给定名称空间（“默认”）下的部署类型 controller 管理的 Pod 列表，但返回的列表不包含 Pod 列表

labelSelector := labels.Set(obj.Spec.Selector.MatchLabels)

其中obj的类型为*appsv1.Deployment来自https://pkg.go.dev/k8s.io/api/apps/v1?tab=doc#Deployment

podsList, err := getPodList(string(labelSelector.AsSelector().String()), kubeClient, res.Namespace)

function 的定义是

func getPodList( labelSelector string, client kubernetes.Interface, ns string ) (*corev1.PodList, error) {     
     options := metav1.ListOptions{
         LabelSelector: labelSelector,
     }

     podList, err := client.CoreV1().Pods(ns).List(options)
     return podList, err
 }

返回的类型 - https://pkg.go.dev/k8s.io/api/core/v1?tab=doc#PodList应该包含Items []Pod切片，这在我返回的信息中不可用。

在Go代码中使用以下包

appsv1 "k8s.io/api/apps/v1"    
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/client-go/kubernetes"

Answer 1

似乎我一直都在使用它，但只是错误地处理了CoreV1().Pods(ns).List(options)的返回类型。 它返回一个指向PodList切片的指针 - https://pkg.go.dev/k8s.io/api/core/v1?tab=doc#PodList

这是我所做的对后代有用的最小代码

package main

import (
        "fmt"
        metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
        "k8s.io/client-go/kubernetes"
        "k8s.io/client-go/tools/clientcmd"
        "os"
        "path/filepath"
)

func main() {

        kubeconfig := filepath.Join(
                os.Getenv("HOME"), ".kube", "config",
        )

        // Initialize kubernetes-client
        cfg, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
        if err != nil {
                fmt.Printf("Error building kubeconfig: %v\n", err)
                os.Exit(1)
        }

        // create new client with the given config
        // https://pkg.go.dev/k8s.io/client-go/kubernetes?tab=doc#NewForConfig
        kubeClient, err := kubernetes.NewForConfig(cfg)
        if err != nil {
                fmt.Printf("Error building kubernetes clientset: %v\n", err)
                os.Exit(2)
        }

        // use the app's label selector name. Remember this should match with 
        // the deployment selector's matchLabels. Replace <APPNAME> with the 
        // name of your choice
        options := metav1.ListOptions{
                LabelSelector: "app=<APPNAME>",
        }

        // get the pod list
        // https://pkg.go.dev/k8s.io/client-go@v11.0.0+incompatible/kubernetes/typed/core/v1?tab=doc#PodInterface
        podList, _ := kubeClient.CoreV1().Pods("default").List(options)

        // List() returns a pointer to slice, derefernce it, before iterating
        for _, podInfo := range (*podList).Items {
                fmt.Printf("pods-name=%v\n", podInfo.Name)
                fmt.Printf("pods-status=%v\n", podInfo.Status.Phase)
                fmt.Printf("pods-condition=%v\n", podInfo.Status.Conditions)
        }
}