Question

我正在尝试使用https://kubernetes.io/docs/tasks/administer-cluster/dns-debugging-resolution/

在kubernetes中学习DNS。

我部署了busybox
from multiprocessing import Process p1 = Process(target=subprocess.call, args=(cmd,)) processTimeout = 50 p1.start() p1.join(processTimeout) if p1.is_alive(): p1.terminate()
```
kubectl get pods busybox -o wide
```
NAME READY STATUS RESTARTS AGE IP NODE busybox 1/1 Running 0 16m 10.200.1.5 worker-1
```
kubectl exec -ti busybox -- nslookup kubernetes.default
```

是否需要修改worker-1节点的/etc/resolv.conf文件。当前/etc/resolv.conf内容在下面

Server:    10.32.0.10
Address 1: 10.32.0.10 kube-dns.kube-system.svc.cluster.local

nslookup: can't resolve 'kubernetes.default'
command terminated with exit code 1

也是worker-1的版本 lsb_release -a 没有可用的LSB模块。发行人ID：Ubuntu 说明：Ubuntu 18.04.1 LTS 发行：18.04 代号：bionic

请帮助我找出导致配置错误的配置。我需要根据什么来更改resolve.conf文件吗？

Answer 1

您遇到了最新版本的busybox docker映像中的错误。使用标签busybox:1.28代替latest。 bug link is here：

"Nslookup does not work in latest busybox image"
"1.27/1.28 are working , 1.29/1.29.1 are not"

这是带有<{1>}标签的失败。

busybox:latest

以下是带有$ kubectl run busybox --image busybox:latest --restart=Never --rm -it busybox -- sh If you don't see a command prompt, try pressing enter. / # nslookup kubernetes.default Server: 10.96.0.10 Address: 10.96.0.10:53 ** server can't find kubernetes.default: NXDOMAIN *** Can't find kubernetes.default: No answer / # exit pod "busybox" deleted标签的相同命令成功。

busybox:1.28

Answer 2

尝试一下。

apiVersion: v1
kind: Pod
metadata:
  name: dnsutils
  namespace: default
spec:
  containers:
  - name: dnsutils
    image: gcr.io/kubernetes-e2e-test-images/dnsutils:1.3
    command:
      - sleep
      - "3600"
    imagePullPolicy: IfNotPresent
  restartPolicy: Always

save this in yaml format and run kubectl apply -f <filename>.yaml and then run below command

vagrant@kubemaster:~$ kubectl exec -i -t dnsutils -- nslookup 10-40-0-2.default.pod  | tee nginx-pod
Server:     10.96.0.10
Address:    10.96.0.10#53

Name:   10-40-0-2.default.pod.cluster.local
Address: 10.40.0.2

It should resolve the output and save it in the file.

nslookup：无法解析kubernetes.default

2 个答案: