k8s-pod-pod内程序操作k8s资源(InClusterConfig)

人生必须的知识就是引人向光明方面的明灯。这篇文章主要讲述k8s-pod-pod内程序操作k8s资源(InClusterConfig)相关的知识，希望能为你提供帮助。
当我们开发一个程序，需要访问k8s集群中的pod、deployment等资源时，会使用k8s.io/client-go模块，在使用这个模块时，我们要有如下几步：
1.获取config对象
clientcmd.BuildConfigFromFlags 根据config路径获取config
rest.InClusterConfig 直接使用pod中自带的token等内容
2.获取k8s client
3.使用k8s client获取k8s资源

package main

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

func main()
kubeConfig, err := CreateKubeConfig()
if err != nil
panic(err)

kubeClient, err := kubernetes.NewForConfig(kubeConfig)
if err != nil
panic(err)

//获取pod资源
kubeClient.CoreV1().Pods("").List(context.Background(),v1.ListOptions)

func PathExists(path string) (bool, error)
_, err := os.Stat(path)
if err == nil
return true, nil

if os.IsNotExist(err)
return false, nil

return false, err

func CreateKubeConfig() (*rest.Config, error)
kubeConfigPath := ""
if home := homedir.HomeDir(); home != ""
kubeConfigPath = filepath.Join(home, ".kube", "config")

fileExist, err := PathExists(kubeConfigPath)
if err != nil
return nil, fmt.Errorf("justify kubeConfigPath exist err,err:%v", err)

//.kube/config文件存在，就使用文件
//这里主要是本地测试
if fileExist
config, err := clientcmd.BuildConfigFromFlags("", kubeConfigPath)
if err != nil
return nil, err

return config, nil
else
//当程序以pod方式运行时，就直接走这里的逻辑
config, err := rest.InClusterConfig()
if err != nil
return nil, err

return config, nil

下面我们主要介绍下InClusterConfig
1.创建serviceAccount【k8s-pod-pod内程序操作k8s资源(InClusterConfig)】要想操作k8s的相关资源，需要给某个serviceAccount授权
如上：我们要操作pod资源，就要创建如下资源
创建如下资源后，opPodServiceAccount这个serviceAccout就有操作pod的权限了

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
creationTimestamp: null
name: opPodClusterRole
rules:
- apiGroups:
- ""
resources:
- pods
verbs:
- list
- watch

---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: opPodClusterRoleBinding
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: opPodClusterRole
subjects:
- kind: ServiceAccount
name: opPodServiceAccount
namespace: default
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: opPodServiceAccount
namespace: default

2.指定运行程序的pod使用上面的ServiceAccountserviceAccount: live-media-watch-pod

apiVersion: apps/v1
kind: Deployment
metadata:
labels:
operator: live-media-watch-pod
name: live-media-watch-pod
namespace: bixin-system
spec:
replicas: 1
selector:
matchLabels:
operator: live-media-watch-pod
strategy:
rollingUpdate:
maxSurge: 100%
maxUnavailable: 0
type: RollingUpdate
template:
metadata:
creationTimestamp: null
labels:
operator: live-media-watch-pod
spec:
containers:
- image: ******.**.com/k8s/live-media-watch-pod:202201211654
imagePullPolicy: IfNotPresent
livenessProbe:
failureThreshold: 10
httpGet:
path: healthz
port: 8080
scheme: HTTP
initialDelaySeconds: 30
periodSeconds: 5
successThreshold: 1
timeoutSeconds: 3
name: live-media-watch-pod
readinessProbe:
failureThreshold: 10
httpGet:
path: healthz
port: 8080
scheme: HTTP
initialDelaySeconds: 30
periodSeconds: 5
successThreshold: 1
timeoutSeconds: 3
serviceAccount: live-media-watch-pod