Kubernetes nslookup Kubernetes.default失败_Kubernetes_Nslookup_Coredns

Kubernetes nslookup Kubernetes.default失败

kubernetes

Kubernetes nslookup Kubernetes.default失败,kubernetes,nslookup,coredns,Kubernetes,Nslookup,Coredns,我的环境： OS - CentOS-8.2 Kubernetes Vesion: Client Version: v1.18.8 Server Version: v1.18.8 我已经成功地配置了Kubernetes集群（一个主集群和一个工作集群），但是目前在用下面的代码检查dns解析时失败了 apiVersion: v1 kind: Pod metadata: name: dnsutils namespace: default spec: containers: - name

我的环境：

OS - CentOS-8.2
Kubernetes Vesion:
Client Version: v1.18.8
Server Version: v1.18.8

我已经成功地配置了Kubernetes集群（一个主集群和一个工作集群），但是目前在用下面的代码检查dns解析时失败了

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


# kubectl get pods -o wide --all-namespaces
NAMESPACE     NAME                                  READY   STATUS    RESTARTS   AGE     IP                NODE           NOMINATED NODE   READINESS GATES
default       dnsutils                              1/1     Running   0          4m38s   10.244.1.20       K8s-Worker-1   <none>            <none>
kube-system   coredns-66bff467f8-2q4z9              1/1     Running   1          4d14h   10.244.0.5        K8s-Master     <none>            <none>
kube-system   coredns-66bff467f8-ktbd4              1/1     Running   1          4d14h   10.244.0.4        K8s-Master     <none>            <none>
kube-system   etcd-K8s-Master                       1/1     Running   1          4d14h   65.66.67.5        K8s-Master     <none>            <none>
kube-system   kube-apiserver-K8s-Master             1/1     Running   1          4d14h   65.66.67.5        K8s-Master     <none>            <none>
kube-system   kube-controller-manager-K8s-Master    1/1     Running   1          4d14h   65.66.67.5        K8s-Master     <none>            <none>
kube-system   kube-flannel-ds-amd64-d6h9c           1/1     Running   61         45h     65.66.67.6        K8s-Worker-1   <none>            <none>
kube-system   kube-flannel-ds-amd64-tc4qf           1/1     Running   202        4d14h   65.66.67.5        K8s-Master     <none>            <none>
kube-system   kube-proxy-cl9n4                      1/1     Running   0          45h     65.66.67.6        K8s-Worker-1   <none>            <none>
kube-system   kube-proxy-s7jlc                      1/1     Running   1          4d14h   65.66.67.5        K8s-Master     <none>            <none>
kube-system   kube-scheduler-K8s-Master             1/1     Running   1          4d14h   65.66.67.5        K8s-Master     <none>            <none>

# kubectl get pods
NAME       READY   STATUS    RESTARTS   AGE
dnsutils   1/1     Running   0          22m

# kubectl exec -i -t dnsutils -- nslookup kubernetes.default
;; connection timed out; no servers could be reached

command terminated with exit code 1


# kubectl exec -ti dnsutils -- cat /etc/resolv.conf
nameserver 10.96.0.10
search default.svc.cluster.local svc.cluster.local cluster.local company.domain.com
options ndots:5


# kubectl get pods --namespace=kube-system -l k8s-app=kube-dns
NAME                       READY   STATUS    RESTARTS   AGE
coredns-66bff467f8-2q4z9   1/1     Running   1          4d14h
coredns-66bff467f8-ktbd4   1/1     Running   1          4d14h

# kubectl logs --namespace=kube-system -l k8s-app=kube-dns
.:53
[INFO] plugin/reload: Running configuration MD5 = 4e235fcc3696966e76816bcd9034ebc7
CoreDNS-1.6.7
linux/amd64, go1.13.6, da7f65b
.:53
[INFO] plugin/reload: Running configuration MD5 = 4e235fcc3696966e76816bcd9034ebc7
CoreDNS-1.6.7
linux/amd64, go1.13.6, da7f65b


# kubectl get svc --namespace=kube-system
NAME       TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)                  AGE
kube-dns   ClusterIP   10.96.0.10   <none>        53/UDP,53/TCP,9153/TCP   4d14h

# kubectl get endpoints kube-dns --namespace=kube-system
NAME       ENDPOINTS                                                 AGE
kube-dns   10.244.0.4:53,10.244.0.5:53,10.244.0.4:9153 + 3 more...   4d14h


# kubectl describe svc -n kube-system kube-dns
Name:              kube-dns
Namespace:         kube-system
Labels:            k8s-app=kube-dns
                   kubernetes.io/cluster-service=true
                   kubernetes.io/name=KubeDNS
Annotations:       prometheus.io/port: 9153
                   prometheus.io/scrape: true
Selector:          k8s-app=kube-dns
Type:              ClusterIP
IP:                10.96.0.10
Port:              dns  53/UDP
TargetPort:        53/UDP
Endpoints:         10.244.0.4:53,10.244.0.5:53
Port:              dns-tcp  53/TCP
TargetPort:        53/TCP
Endpoints:         10.244.0.4:53,10.244.0.5:53
Port:              metrics  9153/TCP
TargetPort:        9153/TCP
Endpoints:         10.244.0.4:9153,10.244.0.5:9153
Session Affinity:  None
Events:            <none>

# kubectl describe svc kubernetes
Name:              kubernetes
Namespace:         default
Labels:            component=apiserver
                   provider=kubernetes
Annotations:       <none>
Selector:          <none>
Type:              ClusterIP
IP:                10.96.0.1
Port:              https  443/TCP
TargetPort:        6443/TCP
Endpoints:         65.66.67.5:6443
Session Affinity:  None
Events:            <none>

apiVersion:v1 种类：豆荚元数据：姓名：dnsutils 名称空间：默认值规格：容器： -姓名：dnsutils 图片：gcr.io/kubernetes-e2e-test-images/dnsutils:1.3 命令： -睡眠 - "3600" imagePullPolicy:如果不存在 restartPolicy：始终 #kubectl获得pods-o宽——所有名称空间命名空间名称就绪状态重新启动老化IP节点指定节点就绪门默认dnsutils 1/1运行0 4m38s 10.244.1.20 K8s-Worker-1 kube系统coredns-66bff467f8-2q4z9 1/1运行1 4d14h 10.244.0.5 K8s主机 kube系统coredns-66bff467f8-ktbd4 1/1运行1 4d14h 10.244.0.4 K8s主机 kube系统etcd-K8s-Master 1/1运行1 4d14h 65.66.67.5 K8s Master kube系统kube-apiserver-K8s-Master 1/1运行1 4d14h 65.66.67.5 K8s Master kube系统kube-controller-manager-K8s-Master 1/1运行1 4d14h 65.66.67.5 K8s Master kube系统kube-flannel-ds-amd64-d6h9c 1/1运行61 45h 65.66.67.6 K8s-WOER-1 kube系统kube-flannel-ds-amd64-tc4qf 1/1运行202 4d14h 65.66.67.5 K8s主机 kube系统kube-proxy-cl9n4 1/1运行0 45h 65.66.67.6 K8s-Worker-1 kube系统kube-proxy-s7jlc 1/1运行1 4d14h 65.66.67.5 K8s主机 kube系统kube-scheduler-K8s-Master 1/1运行1 4d14h 65.66.67.5 K8s Master #kubectl得到豆荚名称就绪状态重新启动 dnsutils 1/1运行0 22m 当前，在Kubernetes群集主机和nslookup Kubernetes.default上执行的以下命令失败

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


# kubectl get pods -o wide --all-namespaces
NAMESPACE     NAME                                  READY   STATUS    RESTARTS   AGE     IP                NODE           NOMINATED NODE   READINESS GATES
default       dnsutils                              1/1     Running   0          4m38s   10.244.1.20       K8s-Worker-1   <none>            <none>
kube-system   coredns-66bff467f8-2q4z9              1/1     Running   1          4d14h   10.244.0.5        K8s-Master     <none>            <none>
kube-system   coredns-66bff467f8-ktbd4              1/1     Running   1          4d14h   10.244.0.4        K8s-Master     <none>            <none>
kube-system   etcd-K8s-Master                       1/1     Running   1          4d14h   65.66.67.5        K8s-Master     <none>            <none>
kube-system   kube-apiserver-K8s-Master             1/1     Running   1          4d14h   65.66.67.5        K8s-Master     <none>            <none>
kube-system   kube-controller-manager-K8s-Master    1/1     Running   1          4d14h   65.66.67.5        K8s-Master     <none>            <none>
kube-system   kube-flannel-ds-amd64-d6h9c           1/1     Running   61         45h     65.66.67.6        K8s-Worker-1   <none>            <none>
kube-system   kube-flannel-ds-amd64-tc4qf           1/1     Running   202        4d14h   65.66.67.5        K8s-Master     <none>            <none>
kube-system   kube-proxy-cl9n4                      1/1     Running   0          45h     65.66.67.6        K8s-Worker-1   <none>            <none>
kube-system   kube-proxy-s7jlc                      1/1     Running   1          4d14h   65.66.67.5        K8s-Master     <none>            <none>
kube-system   kube-scheduler-K8s-Master             1/1     Running   1          4d14h   65.66.67.5        K8s-Master     <none>            <none>

# kubectl get pods
NAME       READY   STATUS    RESTARTS   AGE
dnsutils   1/1     Running   0          22m

# kubectl exec -i -t dnsutils -- nslookup kubernetes.default
;; connection timed out; no servers could be reached

command terminated with exit code 1


# kubectl exec -ti dnsutils -- cat /etc/resolv.conf
nameserver 10.96.0.10
search default.svc.cluster.local svc.cluster.local cluster.local company.domain.com
options ndots:5


# kubectl get pods --namespace=kube-system -l k8s-app=kube-dns
NAME                       READY   STATUS    RESTARTS   AGE
coredns-66bff467f8-2q4z9   1/1     Running   1          4d14h
coredns-66bff467f8-ktbd4   1/1     Running   1          4d14h

# kubectl logs --namespace=kube-system -l k8s-app=kube-dns
.:53
[INFO] plugin/reload: Running configuration MD5 = 4e235fcc3696966e76816bcd9034ebc7
CoreDNS-1.6.7
linux/amd64, go1.13.6, da7f65b
.:53
[INFO] plugin/reload: Running configuration MD5 = 4e235fcc3696966e76816bcd9034ebc7
CoreDNS-1.6.7
linux/amd64, go1.13.6, da7f65b


# kubectl get svc --namespace=kube-system
NAME       TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)                  AGE
kube-dns   ClusterIP   10.96.0.10   <none>        53/UDP,53/TCP,9153/TCP   4d14h

# kubectl get endpoints kube-dns --namespace=kube-system
NAME       ENDPOINTS                                                 AGE
kube-dns   10.244.0.4:53,10.244.0.5:53,10.244.0.4:9153 + 3 more...   4d14h


# kubectl describe svc -n kube-system kube-dns
Name:              kube-dns
Namespace:         kube-system
Labels:            k8s-app=kube-dns
                   kubernetes.io/cluster-service=true
                   kubernetes.io/name=KubeDNS
Annotations:       prometheus.io/port: 9153
                   prometheus.io/scrape: true
Selector:          k8s-app=kube-dns
Type:              ClusterIP
IP:                10.96.0.10
Port:              dns  53/UDP
TargetPort:        53/UDP
Endpoints:         10.244.0.4:53,10.244.0.5:53
Port:              dns-tcp  53/TCP
TargetPort:        53/TCP
Endpoints:         10.244.0.4:53,10.244.0.5:53
Port:              metrics  9153/TCP
TargetPort:        9153/TCP
Endpoints:         10.244.0.4:9153,10.244.0.5:9153
Session Affinity:  None
Events:            <none>

# kubectl describe svc kubernetes
Name:              kubernetes
Namespace:         default
Labels:            component=apiserver
                   provider=kubernetes
Annotations:       <none>
Selector:          <none>
Type:              ClusterIP
IP:                10.96.0.1
Port:              https  443/TCP
TargetPort:        6443/TCP
Endpoints:         65.66.67.5:6443
Session Affinity:  None
Events:            <none>

#kubectl exec-i-t dnsutils--nslookup kubernetes.default
;; 连接超时；无法访问任何服务器
命令终止，退出代码为1
#kubectl exec-ti dnsutils-cat/etc/resolv.conf
名称服务器10.96.0.10
搜索default.svc.cluster.local svc.cluster.local cluster.local company.domain.com
备选方案：5
#kubectl get pods——名称空间=kube系统-LK8S应用程序=kube dns
名称就绪状态重新启动
coredns-66bff467f8-2q4z9 1/1运行1 4d14h
coredns-66bff467f8-ktbd4 1/1运行1 4d14h
#kubectl日志--名称空间=kube系统-LK8S应用程序=kube dns
.:53
[信息]插件/重新加载：运行配置MD5=4E235FCC36966E76816BCD9034EBC7
CoreDNS-1.6.7
linux/amd64，go1.13.6，da7f65b
.:53
[信息]插件/重新加载：运行配置MD5=4E235FCC36966E76816BCD9034EBC7
CoreDNS-1.6.7
linux/amd64，go1.13.6，da7f65b
#kubectl get svc--namespace=kube系统
名称类型CLUSTER-IP外部IP端口年龄
kube dns ClusterIP 10.96.0.10 53/UDP、53/TCP、9153/TCP 4d14h
#kubectl获取端点kube dns--名称空间=kube系统
姓名端点年龄
kube dns 10.244.0.4:53,10.244.0.5:53,10.244.0.4:9153+3更多。。。4d14h
#kubectl描述svc-n kube系统kube dns
名称：kube dns
名称空间：kube系统
标签：k8s app=kube dns
kubernetes.io/cluster service=true
kubernetes.io/name=KubeDNS
注释：prometheus.io/port:9153
普罗米修斯：对
选择器：k8s app=kube dns
类型：集群
IP:10.96.0.10
端口：dns 53/UDP
目标端口：53/UDP
终点：10.244.0.4:53,10.244.0.5:53
端口：dns tcp 53/tcp
目标端口：53/TCP
终点：10.244.0.4:53,10.244.0.5:53
端口：metrics 9153/TCP
目标端口：9153/TCP
终点：10.244.0.4:9153,10.244.0.5:9153
会话关联：无
活动：
#kubectl描述svc kubernetes
姓名：kubernetes
名称空间：默认值
标签：组件=apiserver
提供者=kubernetes
注释：
选择器：
类型：集群
IP:10.96.0.1
端口：https 443/TCP
目标端口：6443/TCP
终点：65.66.67.5:6443
会话关联：无
活动：

有人能帮我调试这个问题吗。谢谢。

我已经卸载并重新安装了Kubernetes版本-v1.19.0现在一切正常。谢谢。

添加

kubectl description svc kubernetes的输出

@ArghyaSadhu，添加了有问题的输出部分。