Kubernetes DNS在本地Ubuntu 18.04环境下不工作

我试图在本地计算机（Ubuntu18.04）上部署Kubernetes系统，但DNS服务出现了一些问题（我无法通过其DNS名称与headless服务交谈）

我使用minikube运行集群，版本为-

Client Version: version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.2", GitCommit:"59603c6e503c87169aea6106f57b9f242f64df89", GitTreeState:"clean", BuildDate:"2020-01-18T23:30:10Z", GoVersion:"go1.13.5", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.2", GitCommit:"59603c6e503c87169aea6106f57b9f242f64df89", GitTreeState:"clean", BuildDate:"2020-01-18T23:22:30Z", GoVersion:"go1.13.5", Compiler:"gc", Platform:"linux/amd64"}

无头服务-

NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)             AGE
kubernetes           ClusterIP   10.96.0.1    <none>        443/TCP             67m
zookeeper-headless   ClusterIP   None         <none>        2888/TCP,3888/TCP   3m58s

DNS服务终结点不存在-（

kubectl get ep kube DNS--namespace=kube system

）

DNS吊舱（未准备就绪）——

DNS pod的日志为-

[信息]插件/重新加载：运行配置MD5= 4E235FCC36966E76816BCD9034EBC7核心DNS-1.6.5 linux/amd64，go1.13.4， c2fd1b2[INFO]插件/准备就绪：仍在等待：“kubernetes”[INFO] plugin/ready:仍在等待：“kubernetes”[INFO]plugin/ready: 还在等待：“库伯内特斯”E0221 12:50:23.090626 1 [现场：125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector。go:98： 未能列出*v1。终结点：获取 : 拨号tcp 10.96.0.1:443:i/o超时E0221 12:50:23.090668 1 [现场：125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector。go:98： 未能列出*v1。服务：获取 : 拨号tcp 10.96.0.1:443:i/o超时E0221 12:50:23.090671 1 [现场：125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector。go:98： 未能列出*v1。命名空间：获取 : 拨tcp 10.96.0.1:443:i/o超时I0221 12:50:23.090594 1 trace.go:82]trace[146678255]：“反射器 pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.执行编号：98 ListAndWatch”（开始时间：2020-02-21 12:49:53.090061147+0000 UTC m=+0.011664556）（总时间：30.000405618s）：记录道[146678255]： [30.000405618s][30.000405618s]结束E0221 12:50:23.090626 1 [现场：125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector。go:98： 未能列出*v1。终结点：获取 : 拨号tcp 10.96.0.1:443:i/o超时E0221 12:50:23.090626 1 [现场：125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector。go:98： 未能列出*v1。终结点：获取 : 拨号tcp 10.96.0.1:443:i/o超时E0221 12:50:23.090626 1 [现场：125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector。go:98： 未能列出*v1。终结点：获取 : 拨tcp 10.96.0.1:443:i/o超时I0221 12:50:23.090644 1 trace.go:82]trace[653875127]：“反射器 pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.执行编号：98 ListAndWatch”（开始时间：2020-02-21 12:49:53.090057185+0000 UTC m=+0.011660587）（总时间：30.00054106s）：记录道[653875127]： [30.00054106s][30.00054106s]结束I0221 12:50:23.090654 1 trace.go:82]trace[1501712764]：“反射器 pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.执行编号：98 ListAndWatch”（开始时间：2020-02-21 12:49:53.090052023+0000 UTC m=+0.011655434）（总时间：30.000437703s）：跟踪[1501712764]： [30.000437703s][30.000437703s]结束E0221 12:50:23.090668 1 [现场：125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector。go:98： 未能列出*v1。服务：获取 : 拨号tcp 10.96.0.1:443:i/o超时E0221 12:50:23.090668 1 [现场：125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector。go:98： 未能列出*v1。服务：获取 : 拨号tcp 10.96.0.1:443:i/o超时E0221 12:50:23.090668 1 [现场：125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector。go:98： 未能列出*v1。服务：获取 : 拨号tcp 10.96.0.1:443:i/o超时E0221 12:50:23.090671 1 [现场：125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector。go:98： 未能列出*v1。命名空间：获取 : 拨号tcp 10.96.0.1:443:i/o超时E0221 12:50:23.090671 1 [现场：125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector。go:98： 未能列出*v1。命名空间：获取 : 拨号tcp 10.96.0.1:443:i/o超时E0221 12:50:23.090671 1 [现场：125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector。go:98： 未能列出*v1。命名空间：获取 : 拨tcp 10.96.0.1:443:i/o超时[信息]插件/准备就绪：仍在等待 关于：“kubernetes”[INFO]插件/准备就绪：仍在等待：“kubernetes” [信息]插件/准备就绪：仍在等待：“kubernetes”

我试着跑-

kubectl run -i --tty --image busybox:1.28 dns-test --restart=Never --rm
/ # nslookup headless.default.svc.cluster.local

并且得到-

Server:    10.96.0.10
Address 1: 10.96.0.10

nslookup: can't resolve 'headless.default.svc.cluster.local'

我甚至不知道从哪里开始解决这个问题。有人能帮忙吗

更新

我想我明白问题的原因，但我不明白为什么会发生这种情况。 问题似乎发生在防火墙被激活之后。由于某些原因，核心dns吊舱无法运行，并陷入就绪状态。在我通过运行关闭防火墙后-

sudo ufw disable

核心dns pods状态已更改为运行，服务现在具有端点地址

 kubectl run -i --tty --image busybox:1.28 dns-test --restart=Never --rm
If you don't see a command prompt, try pressing enter.
/ # nslookup  zookeeper-headless.default
Server:    10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local

Name:      zookeeper-headless.default
Address 1: 172.17.0.4 zookeeper-statefulset-1.zookeeper-headless.default.svc.cluster.local
Address 2: 172.17.0.5 zookeeper-statefulset-0.zookeeper-headless.default.svc.cluster.local
Address 3: 172.17.0.6 zookeeper-statefulset-2.zookeeper-headless.default.svc.cluster.local

 kubectl run -i --tty --image busybox:1.28 dns-test --restart=Never --rm
If you don't see a command prompt, try pressing enter.
/ # nslookup  zookeeper-headless.default
Server:    10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local

Name:      zookeeper-headless.default
Address 1: 172.17.0.4 zookeeper-statefulset-1.zookeeper-headless.default.svc.cluster.local
Address 2: 172.17.0.5 zookeeper-statefulset-0.zookeeper-headless.default.svc.cluster.local
Address 3: 172.17.0.6 zookeeper-statefulset-2.zookeeper-headless.default.svc.cluster.local

---

我想我知道是什么导致了这个问题，但我不明白为什么会发生。 问题似乎发生在防火墙被激活之后。由于某些原因，核心dns吊舱无法运行，并陷入就绪状态。在我通过运行关闭防火墙之后-

sudo ufw disable

核心dns pods状态已更改为运行，服务现在具有端点地址

 kubectl run -i --tty --image busybox:1.28 dns-test --restart=Never --rm
If you don't see a command prompt, try pressing enter.
/ # nslookup  zookeeper-headless.default
Server:    10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local

Name:      zookeeper-headless.default
Address 1: 172.17.0.4 zookeeper-statefulset-1.zookeeper-headless.default.svc.cluster.local
Address 2: 172.17.0.5 zookeeper-statefulset-0.zookeeper-headless.default.svc.cluster.local
Address 3: 172.17.0.6 zookeeper-statefulset-2.zookeeper-headless.default.svc.cluster.local

 kubectl run -i --tty --image busybox:1.28 dns-test --restart=Never --rm
If you don't see a command prompt, try pressing enter.
/ # nslookup  zookeeper-headless.default
Server:    10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local

Name:      zookeeper-headless.default
Address 1: 172.17.0.4 zookeeper-statefulset-1.zookeeper-headless.default.svc.cluster.local
Address 2: 172.17.0.5 zookeeper-statefulset-0.zookeeper-headless.default.svc.cluster.local
Address 3: 172.17.0.6 zookeeper-statefulset-2.zookeeper-headless.default.svc.cluster.local

---

提供核心dns pod的日志没有日志，您只需复制/粘贴pod的

kubectl description

输出。您使用的是什么cni？法兰绒还是别的？你给的苹果酒是什么？你是如何设置集群的，kubeadm还是其他什么？对不起，我修复了它并添加了日志@arghyasadhu你正在尝试访问

headle
NAME       ENDPOINTS                                               AGE
kube-dns   172.17.0.2:53,172.17.0.3:53,172.17.0.2:53 + 3 more...   34m

NAMESPACE     NAME                             READY   STATUS    RESTARTS           12m
kube-system   coredns-6955765f44-2d8md         1/1     Running   4          34m
kube-system   coredns-6955765f44-n2gcp         1/1     Running   4          34m

 kubectl run -i --tty --image busybox:1.28 dns-test --restart=Never --rm
If you don't see a command prompt, try pressing enter.
/ # nslookup  zookeeper-headless.default
Server:    10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local

Name:      zookeeper-headless.default
Address 1: 172.17.0.4 zookeeper-statefulset-1.zookeeper-headless.default.svc.cluster.local
Address 2: 172.17.0.5 zookeeper-statefulset-0.zookeeper-headless.default.svc.cluster.local
Address 3: 172.17.0.6 zookeeper-statefulset-2.zookeeper-headless.default.svc.cluster.local

NAME       ENDPOINTS                                               AGE
kube-dns   172.17.0.2:53,172.17.0.3:53,172.17.0.2:53 + 3 more...   34m

NAMESPACE     NAME                             READY   STATUS    RESTARTS           12m
kube-system   coredns-6955765f44-2d8md         1/1     Running   4          34m
kube-system   coredns-6955765f44-n2gcp         1/1     Running   4          34m