Kubernetes DNS 不适用于本地 Ubuntu 18.04 环境
Kubernetes DNS not working on local Ubuntu 18.04 environment
我试图在我的本地计算机 (Ubuntu 18.04) 上部署 Kubernetes 系统，但 DNS 服务有一些问题（我无法通过他们的 DNS 名称与无头服务对话）。
我将 minikube 用于 运行 集群，版本是 -
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
pods -
NAME READY STATUS RESTARTS AGE
zookeeper-statefulset-0 1/1 Running 1 57m
zookeeper-statefulset-1 1/1 Running 1 56m
zookeeper-statefulset-2 1/1 Running 1 54m
不存在的 DNS 服务端点 - (kubectl get ep kube-dns --namespace=kube-system)
NAME ENDPOINTS AGE
kube-dns 68m
DNS pods（未准备好）-
NAME READY STATUS RESTARTS AGE
coredns-6955765f44-gv42p 0/1 Running 1 58m
coredns-6955765f44-rfkm2 0/1 Running 1 58m
DNS pod 的日志是 -
[INFO] plugin/reload: Running configuration MD5 =
4e235fcc3696966e76816bcd9034ebc7 CoreDNS-1.6.5 linux/amd64, go1.13.4,
c2fd1b2 [INFO] plugin/ready: Still waiting on: "kubernetes" [INFO]
plugin/ready: Still waiting on: "kubernetes" [INFO] plugin/ready:
Still waiting on: "kubernetes" E0221 12:50:23.090626 1
reflector.go:125]
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98:
Failed to list *v1.Endpoints: Get
https://10.96.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0:
dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090668 1
reflector.go:125]
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98:
Failed to list *v1.Service: Get
https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0:
dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090671 1
reflector.go:125]
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98:
Failed to list *v1.Namespace: Get
https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0:
dial tcp 10.96.0.1:443: i/o timeout I0221 12:50:23.090594 1
trace.go:82] Trace[146678255]: "Reflector
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98
ListAndWatch" (started: 2020-02-21 12:49:53.090061147 +0000 UTC
m=+0.011664556) (total time: 30.000405618s): Trace[146678255]:
[30.000405618s] [30.000405618s] END E0221 12:50:23.090626 1
reflector.go:125]
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98:
Failed to list *v1.Endpoints: Get
https://10.96.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0:
dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090626 1
reflector.go:125]
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98:
Failed to list *v1.Endpoints: Get
https://10.96.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0:
dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090626 1
reflector.go:125]
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98:
Failed to list *v1.Endpoints: Get
https://10.96.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0:
dial tcp 10.96.0.1:443: i/o timeout I0221 12:50:23.090644 1
trace.go:82] Trace[653875127]: "Reflector
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98
ListAndWatch" (started: 2020-02-21 12:49:53.090057185 +0000 UTC
m=+0.011660587) (total time: 30.00054106s): Trace[653875127]:
[30.00054106s] [30.00054106s] END I0221 12:50:23.090654 1
trace.go:82] Trace[1501712764]: "Reflector
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98
ListAndWatch" (started: 2020-02-21 12:49:53.090052023 +0000 UTC
m=+0.011655434) (total time: 30.000437703s): Trace[1501712764]:
[30.000437703s] [30.000437703s] END E0221 12:50:23.090668 1
reflector.go:125]
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98:
Failed to list *v1.Service: Get
https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0:
dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090668 1
reflector.go:125]
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98:
Failed to list *v1.Service: Get
https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0:
dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090668 1
reflector.go:125]
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98:
Failed to list *v1.Service: Get
https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0:
dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090671 1
reflector.go:125]
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98:
Failed to list *v1.Namespace: Get
https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0:
dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090671 1
reflector.go:125]
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98:
Failed to list *v1.Namespace: Get
https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0:
dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090671 1
reflector.go:125]
pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98:
Failed to list *v1.Namespace: Get
https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0:
dial tcp 10.96.0.1:443: i/o timeout [INFO] plugin/ready: Still waiting
on: "kubernetes" [INFO] plugin/ready: Still waiting on: "kubernetes"
[INFO] plugin/ready: Still waiting on: "kubernetes"
我试过 运行宁 -
kubectl run -i --tty --image busybox:1.28 dns-test --restart=Never --rm
/ # nslookup headless.default.svc.cluster.local
并得到 -
Server: 10.96.0.10
Address 1: 10.96.0.10
nslookup: can't resolve 'headless.default.svc.cluster.local'
我什至不知道从哪里开始解决这个问题。有人可以帮忙吗？
更新
我想我明白是什么导致了这个问题，但我不明白为什么会这样。
问题似乎是在防火墙激活后发生的。出于某种原因，core-dns pods 不能 运行 并卡在就绪状态。在我通过 运行ning 关闭防火墙后 -
sudo ufw disable
core-dns pods 状态已更改为 Running 并且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
.
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
我想我明白是什么导致了这个问题，但我不明白为什么会这样。
问题似乎是在防火墙激活后发生的。出于某种原因，core-dns pods 无法 运行 并卡在就绪状态。在我通过 运行ning -
关闭防火墙后
sudo ufw disable
core-dns pods 状态已更改为 Running，服务现在有端点地址。
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
.
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
我试图在我的本地计算机 (Ubuntu 18.04) 上部署 Kubernetes 系统，但 DNS 服务有一些问题（我无法通过他们的 DNS 名称与无头服务对话）。
我将 minikube 用于 运行 集群，版本是 -
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
pods -
NAME READY STATUS RESTARTS AGE
zookeeper-statefulset-0 1/1 Running 1 57m
zookeeper-statefulset-1 1/1 Running 1 56m
zookeeper-statefulset-2 1/1 Running 1 54m
不存在的 DNS 服务端点 - (kubectl get ep kube-dns --namespace=kube-system)
NAME ENDPOINTS AGE
kube-dns 68m
DNS pods（未准备好）-
NAME READY STATUS RESTARTS AGE
coredns-6955765f44-gv42p 0/1 Running 1 58m
coredns-6955765f44-rfkm2 0/1 Running 1 58m
DNS pod 的日志是 -
[INFO] plugin/reload: Running configuration MD5 = 4e235fcc3696966e76816bcd9034ebc7 CoreDNS-1.6.5 linux/amd64, go1.13.4, c2fd1b2 [INFO] plugin/ready: Still waiting on: "kubernetes" [INFO] plugin/ready: Still waiting on: "kubernetes" [INFO] plugin/ready: Still waiting on: "kubernetes" E0221 12:50:23.090626 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: Failed to list *v1.Endpoints: Get https://10.96.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090668 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090671 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: Failed to list *v1.Namespace: Get https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout I0221 12:50:23.090594 1 trace.go:82] Trace[146678255]: "Reflector pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98 ListAndWatch" (started: 2020-02-21 12:49:53.090061147 +0000 UTC m=+0.011664556) (total time: 30.000405618s): Trace[146678255]: [30.000405618s] [30.000405618s] END E0221 12:50:23.090626 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: Failed to list *v1.Endpoints: Get https://10.96.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090626 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: Failed to list *v1.Endpoints: Get https://10.96.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090626 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: Failed to list *v1.Endpoints: Get https://10.96.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout I0221 12:50:23.090644 1 trace.go:82] Trace[653875127]: "Reflector pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98 ListAndWatch" (started: 2020-02-21 12:49:53.090057185 +0000 UTC m=+0.011660587) (total time: 30.00054106s): Trace[653875127]: [30.00054106s] [30.00054106s] END I0221 12:50:23.090654 1 trace.go:82] Trace[1501712764]: "Reflector pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98 ListAndWatch" (started: 2020-02-21 12:49:53.090052023 +0000 UTC m=+0.011655434) (total time: 30.000437703s): Trace[1501712764]: [30.000437703s] [30.000437703s] END E0221 12:50:23.090668 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090668 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090668 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090671 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: Failed to list *v1.Namespace: Get https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090671 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: Failed to list *v1.Namespace: Get https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout E0221 12:50:23.090671 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: Failed to list *v1.Namespace: Get https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout [INFO] plugin/ready: Still waiting on: "kubernetes" [INFO] plugin/ready: Still waiting on: "kubernetes" [INFO] plugin/ready: Still waiting on: "kubernetes"
我试过 运行宁 -
kubectl run -i --tty --image busybox:1.28 dns-test --restart=Never --rm
/ # nslookup headless.default.svc.cluster.local
并得到 -
Server: 10.96.0.10
Address 1: 10.96.0.10
nslookup: can't resolve 'headless.default.svc.cluster.local'
我什至不知道从哪里开始解决这个问题。有人可以帮忙吗？
更新
我想我明白是什么导致了这个问题，但我不明白为什么会这样。
问题似乎是在防火墙激活后发生的。出于某种原因，core-dns pods 不能 运行 并卡在就绪状态。在我通过 运行ning 关闭防火墙后 -
sudo ufw disable
core-dns pods 状态已更改为 Running 并且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
.
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
我想我明白是什么导致了这个问题，但我不明白为什么会这样。 问题似乎是在防火墙激活后发生的。出于某种原因，core-dns pods 无法 运行 并卡在就绪状态。在我通过 运行ning -
关闭防火墙后sudo ufw disable
core-dns pods 状态已更改为 Running，服务现在有端点地址。
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
.
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