Golang在K8s中配置卷与持久化存储方法

/data

client-go

volumeMounts

volumes

emptyDir

ConfigMap

Secret

PersistentVolumeClaim

/app/logs

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-golang-app
spec:
  replicas: 1
  selector:
    matchLabels:
      app: golang-logger
  template:
    metadata:
      labels:
        app: golang-logger
    spec:
      containers:
      - name: app-container
        image: your-golang-app-image:latest
        volumeMounts:
        - name: log-storage
          mountPath: /app/logs # Golang应用将写入这个路径
      volumes:
      - name: log-storage
        emptyDir: {} # 这里使用了临时的emptyDir，Pod重启数据会丢失
---
# 如果需要持久化，则会引用PVC
# apiVersion: apps/v1
# kind: Deployment
# ... (略)
#         volumeMounts:
#         - name: data-storage
#           mountPath: /app/data
#       volumes:
#       - name: data-storage
#         persistentVolumeClaim:
#           claimName: my-app-pvc # 引用一个PVC

package main

import (
    "fmt"
    "io/ioutil"
    "os"
    "time"
)

func main() {
    logFilePath := "/app/logs/application.log" // 与K8s volumeMounts的mountPath对应

    for {
        logEntry := fmt.Sprintf("[%s] Hello from Golang app in K8s! Current time: %s\n",
            os.Getenv("HOSTNAME"), time.Now().Format(time.RFC3339))

        // 写入文件
        err := ioutil.WriteFile(logFilePath, []byte(logEntry), 0644)
        if err != nil {
            fmt.Printf("Error writing to log file: %v\n", err)
        } else {
            fmt.Printf("Successfully wrote to %s\n", logFilePath)
        }

        time.Sleep(5 * time.Second)
    }
}

emptyDir

PersistentVolume

PersistentVolumeClaim

my-app-data-pvc

/app/data

ReadWriteOnce

ReadWriteMany

client-go

client-go

client-go

PersistentVolumeClaim

package main

import (
    "context"
    "fmt"
    "path/filepath"
    "time"

    corev1 "k8s.io/api/core/v1"
    storagev1 "k8s.io/api/storage/v1"
    "k8s.io/apimachinery/pkg/api/resource"
    metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    "k8s.io/client-go/kubernetes"
    "k8s.io/client-go/tools/clientcmd"
    "k8s.io/client-go/util/homedir"
)

func main() {
    // 1. 加载kubeconfig，建立与K8s集群的连接
    var kubeconfig string
    if home := homedir.HomeDir(); home != "" {
        kubeconfig = filepath.Join(home, ".kube", "config")
    } else {
        fmt.Println("Warning: Cannot find home directory, falling back to in-cluster config or default.")
    }

    config, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
    if err != nil {
        // 如果不在本地运行，而是在K8s集群内部运行，通常会使用in-cluster配置
        // config, err = rest.InClusterConfig()
        // if err != nil {
        //  panic(err.Error())
        // }
        panic(err.Error()) // 示例简化处理
    }

    clientset, err := kubernetes.NewForConfig(config)
    if err != nil {
        panic(err.Error())
    }

    // 2. 定义要创建的PVC对象
    pvcName := "my-dynamic-pvc-" + fmt.Sprintf("%d", time.Now().Unix())
    namespace := "default"
    storageClassName := "standard-ssd" // 确保你的集群有这个StorageClass

    pvc := &corev1.PersistentVolumeClaim{
        ObjectMeta: metav1.ObjectMeta{
            Name:      pvcName,
            Namespace: namespace,
            Labels:    map[string]string{"app": "golang-operator-managed"},
        },
        Spec: corev1.PersistentVolumeClaimSpec{
            AccessModes: []corev1.PersistentVolumeAccessMode{
                corev1.ReadWriteOnce,
            },
            StorageClassName: &storageClassName,
            Resources: corev1.ResourceRequirements{
                Requests: corev1.ResourceList{
                    corev1.ResourceStorage: resource.MustParse("5Gi"),
                },
            },
        },
    }

    // 3. 使用client-go创建PVC
    fmt.Printf("Attempting to create PVC '%s' in namespace '%s'...\n", pvcName, namespace)
    createdPvc, err := clientset.CoreV1().PersistentVolumeClaims(namespace).Create(context.TODO(), pvc, metav1.CreateOptions{})
    if err != nil {
        fmt.Printf("Error creating PVC: %v\n", err)
        return
    }
    fmt.Printf("Successfully created PVC '%s'. Status: %s\n", createdPvc.Name, createdPvc.Status.Phase)

    // 4. 等待PVC绑定（可选，但对于需要立即使用的场景很重要）
    fmt.Println("Waiting for PVC to be bound...")
    for i := 0; i < 60; i++ { // 等待最多60秒
        currentPvc, err := clientset.CoreV1().PersistentVolumeClaims(namespace).Get(context.TODO(), pvcName, metav1.GetOptions{})
        if err != nil {
            fmt.Printf("Error getting PVC status: %v\n", err)
            time.Sleep(1 * time.Second)
            continue
        }
        if currentPvc.Status.Phase == corev1.ClaimBound {
            fmt.Printf("PVC '%s' is now Bound to PV '%s'.\n", currentPvc.Name, currentPvc.Spec.VolumeName)
            break
        }
        fmt.Printf("PVC '%s' current phase: %s. Retrying in 1 second...\n", currentPvc.Name, currentPvc.Status.Phase)
        time.Sleep(1 * time.Second)
    }

    // 5. 清理（可选，但对于测试和自动化很重要）
    // fmt.Printf("Deleting PVC '%s'...\n", pvcName)
    // err = clientset.CoreV1().PersistentVolumeClaims(namespace).Delete(context.TODO(), pvcName, metav1.DeleteOptions{})
    // if err != nil {
    //  fmt.Printf("Error deleting PVC: %v\n", err)
    // } else {
    //  fmt.Printf("PVC '%s' deleted successfully.\n", pvcName)
    // }
}

clientset

PersistentVolumeClaim

clientset.CoreV1().PersistentVolumeClaims(namespace).Create()

client-go

client-go