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kubectl 使用根据不同context连接不同服务

kubectl get nodes
NAME STATUS ROLES AGE VERSION
docker-desktop Ready master 11h v1.19.7



kubectl config use-context docker-desktop
Switched to context “docker-desktop”



kubectl cluster-info
Kubernetes master is running at https://kubernetes.docker.internal:6443
KubeDNS is running at https://kubernetes.docker.internal:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
To further debug and diagnose cluster problems, use ‘kubectl cluster-info dump’.



% kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.4/aio/deploy/recommended.yaml
namespace/kubernetes-dashboard created
serviceaccount/kubernetes-dashboard created
service/kubernetes-dashboard created
secret/kubernetes-dashboard-certs created
secret/kubernetes-dashboard-csrf created
secret/kubernetes-dashboard-key-holder created
configmap/kubernetes-dashboard-settings created
role.rbac.authorization.k8s.io/kubernetes-dashboard created
clusterrole.rbac.authorization.k8s.io/kubernetes-dashboard created
rolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created
clusterrolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created



https://kubernetes.io/zh/docs/tasks/extend-kubernetes/http-proxy-access-api/
http://localhost:8001/api/v1/namespaces/kubernetes-dashboard



% kubectl get pods -n kubernetes-dashboard
NAME READY STATUS RESTARTS AGE
dashboard-metrics-scraper-7b59f7d4df-b6qz9 1/1 Running 0 30m
kubernetes-dashboard-665f4c5ff-tp5sm 0/1 CrashLoopBackOff 10 30m




CrashLoopBackOff 告诉我们，Kubernetes 正在尽力启动这个 Pod，但是一个或多个容器已经挂了，或者正被删除。
https://kubernetes.io/zh/docs/setup/production-environment/tools/kubeadm/troubleshooting-kubeadm/



deployment.apps/kubernetes-dashboard created
service/dashboard-metrics-scraper created
deployment.apps/dashboard-metrics-scraper created



% kubectl get pod -n kubernetes-dashboard
NAME READY STATUS RESTARTS AGE
dashboard-metrics-scraper-7b59f7d4df-b6qz9 1/1 Running 0 6m54s
kubernetes-dashboard-665f4c5ff-tp5sm 0/1 CrashLoopBackOff 5 6m54s



% kubectl proxy
Starting to serve on 127.0.0.1:8001
% TOKEN=$(kubectl -n kube-system describe secret default| awk ‘$1==”token:”{print $2}’)
kubectl config set-credentials docker-for-desktop –token=”${TOKEN}”
echo $TOKEN
User “docker-for-desktop” set.
eyJhbGc



no endpoints available for service “https:kubernetes-dashboard:”
https://github.com/kubernetes/dashboard/issues/3322
% kubectl -n kubernetes-dashboard get svc -o wide
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
dashboard-metrics-scraper ClusterIP 10.108.121.130 8000/TCP 14m k8s-app=dashboard-metrics-scraper
kubernetes-dashboard ClusterIP 10.105.145.27 443/TCP 14m k8s-app=kubernetes-dashboard



% kubectl get services
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 443/TCP 11h



% kubectl get namespace
NAME STATUS AGE
default Active 12h
kube-node-lease Active 12h
kube-public Active 12h
kube-system Active 12h
kubernetes-dashboard Active 22m



% kubectl get pods -n kube-public
No resources found in kube-public namespace.



% kubectl logs kubernetes-dashboard-665f4c5ff-tp5sm –namespace=kubernetes-dashboard
2021/03/22 02:41:24 Initializing csrf token from kubernetes-dashboard-csrf secret
panic: an error on the server (“”) has prevented the request from succeeding (get secrets kubernetes-dashboard-csrf)



goroutine 1 [running]:
github.com/kubernetes/dashboard/src/app/backend/client/csrf.(*csrfTokenManager).init(0x4000395040)
/home/runner/work/dashboard/dashboard/src/app/backend/client/csrf/manager.go:41 +0x350



https://docs.aws.amazon.com/eks/latest/userguide/dashboard-tutorial.html
https://github.com/kubernetes/kubernetes/issues/29540



kubectl 最简单的登陆方式是在rancher里copy kubeconfig 文件，当然也可以手动配置，更灵活，可以支持多个集群
https://kubernetes.io/zh/docs/tasks/access-application-cluster/configure-access-multiple-clusters/
https://kubernetes.io/zh/docs/concepts/configuration/organize-cluster-access-kubeconfig/



https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#-em-set-credentials-em-



kubectl 可以根据不同context 链接 不同 服务，注意配置认证的时候，token方式不能配置用户名，否则报
error: more than one authentication method found for xx; found [token basicAuth], only one is allowed
error: you cannot specify more than one authentication method at the same time: –token, –username/–password



kubectl config set-credentials xx –token=yy



% kubectl get pods -n kubernetes-dashboard
NAME READY STATUS RESTARTS AGE
dashboard-metrics-scraper-7b59f7d4df-b6qz9 1/1 Running 0 59m
kubernetes-dashboard-665f4c5ff-tp5sm 0/1 CrashLoopBackOff 15 59m



% kubectl logs kubernetes-dashboard-665f4c5ff-tp5sm –namespace=kubernetes-dashboard
2021/03/22 03:03:12 Starting overwatch
2021/03/22 03:03:12 Using namespace: kubernetes-dashboard
2021/03/22 03:03:12 Using in-cluster config to connect to apiserver
2021/03/22 03:03:12 Using secret token for csrf signing
2021/03/22 03:03:12 Initializing csrf token from kubernetes-dashboard-csrf secret
panic: an error on the server (“”) has prevented the request from succeeding (get secrets kubernetes-dashboard-csrf)



goroutine 1 [running]:
github.com/kubernetes/dashboard/src/app/backend/client/csrf.(csrfTokenManager).init(0x400038c800)
/home/runner/work/dashboard/dashboard/src/app/backend/client/csrf/manager.go:41 +0x350
github.com/kubernetes/dashboard/src/app/backend/client/csrf.NewCsrfTokenManager(…)
/home/runner/work/dashboard/dashboard/src/app/backend/client/csrf/manager.go:66
github.com/kubernetes/dashboard/src/app/backend/client.(clientManager).initCSRFKey(0x4000201680)
/home/runner/work/dashboard/dashboard/src/app/backend/client/manager.go:502 +0xb0
github.com/kubernetes/dashboard/src/app/backend/client.(*clientManager).init(0x4000201680)
/home/runner/work/dashboard/dashboard/src/app/backend/client/manager.go:470 +0x40
github.com/kubernetes/dashboard/src/app/backend/client.NewClientManager(…)
/home/runner/work/dashboard/dashboard/src/app/backend/client/manager.go:551
main.main()
/home/runner/work/dashboard/dashboard/src/app/backend/dashboard.go:105 +0x1dc



https://blog.csdn.net/dengkuo19860718/article/details/101447560
% kubectl get deployment -n kubernetes-dashboard
NAME READY UP-TO-DATE AVAILABLE AGE
dashboard-metrics-scraper 1/1 1 1 4h46m
kubernetes-dashboard 0/1 1 0 4h46m



% kubectl rollout history deployment kubernetes-dashboard -n kubernetes-dashboard
deployment.apps/kubernetes-dashboard
REVISION CHANGE-CAUSE
1



https://stackoverflow.com/questions/64533410/kubernetes-dashboard-an-error-on-the-server-unknown-has-prevented-the-reques%E3%80%81



把ClusterRoleBinding
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: kubernetes-dashboard



改成
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: cluster-admin



The ClusterRoleBinding “kubernetes-dashboard” is invalid: roleRef: Invalid value: rbac.RoleRef{APIGroup:”rbac.authorization.k8s.io”, Kind:”ClusterRole”, Name:”cluster-admin”}: cannot change roleRef



增加


apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
name: kubernetes-dashboard
labels:
k8s-app: kubernetes-dashboard
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: cluster-admin
subjects:



  • kind: ServiceAccount
    name: kubernetes-dashboard
    namespace: kube-system




apiVersion: v1
kind: ServiceAccount
metadata:
name: admin
namespace: kube-system
labels:
kubernetes.io/cluster-service: “true”
addonmanager.kubernetes.io/mode: Reconcile





kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1alpha1
metadata:
name: admin
rules:



  • apiGroups: [“”]
    resources: [“    ”]
    verbs: [“”]
    nonResourceURLs: [“    ”]



Warning: rbac.authorization.k8s.io/v1beta1 ClusterRoleBinding is deprecated in v1.17+, unavailable in v1.22+; use rbac.authorization.k8s.io/v1 ClusterRoleBinding



unable to recognize “kubernetes-dashboard.yaml”: no matches for kind “ClusterRole” in version “rbac.authorization.k8s.io/v1alpha1”
Error from server (Invalid): error when applying patch:
{“metadata”:{“annotations”:{“kubectl.kubernetes.io/last-applied-configuration”:”{"apiVersion":"rbac.authorization.k8s.io/v1beta1","kind":"ClusterRoleBinding","metadata":{"annotations":{},"labels":{"k8s-app":"kubernetes-dashboard"},"name":"kubernetes-dashboard"},"roleRef":{"apiGroup":"rbac.authorization.k8s.io","kind":"ClusterRole","name":"cluster-admin"},"subjects":[{"kind":"ServiceAccount","name":"kubernetes-dashboard","namespace":"kube-system"}]}\n”},”labels”:{“k8s-app”:”kubernetes-dashboard”}},”roleRef”:{“name”:”cluster-admin”},”subjects”:[{“kind”:”ServiceAccount”,”name”:”kubernetes-dashboard”,”namespace”:”kube-system”}]}
to:
Resource: “rbac.authorization.k8s.io/v1beta1, Resource=clusterrolebindings”, GroupVersionKind: “rbac.authorization.k8s.io/v1beta1, Kind=ClusterRoleBinding”
Name: “kubernetes-dashboard”, Namespace: “”
for: “kubernetes-dashboard.yaml”: ClusterRoleBinding.rbac.authorization.k8s.io “kubernetes-dashboard” is invalid: roleRef: Invalid value: rbac.RoleRef{APIGroup:”rbac.authorization.k8s.io”, Kind:”ClusterRole”, Name:”cluster-admin”}: cannot change roleRef



https://stackoverflow.com/questions/60901631/dashboard-not-running
kubectl -n kubernetes-dashboard get all
kubectl -n kubernetes-dashboard describe svc kubernetes-dashboard
kubectl describe pod kubernetes-dashboard-665f4c5ff-tp5sm -n kubernetes-dashboard
Node-Selectors: kubernetes.io/os=linux



kubectl exec -it -n kubernetes-dashboard kubernetes-dashboard-665f4c5ff-tp5sm sh



% kubectl get nodes –show-labels -n kubernetes-dashboard
NAME STATUS ROLES AGE VERSION LABELS
docker-desktop Ready master 17h v1.19.7 beta.kubernetes.io/arch=arm64,beta.kubernetes.io/os=linux,kubernetes.io/arch=arm64,kubernetes.io/hostname=docker-desktop,kubernetes.io/os=linux,node-role.kubernetes.io/master=



% kubectl get nodes –show-labels -n kube-system
NAME STATUS ROLES AGE VERSION LABELS
docker-desktop Ready master 17h v1.19.7 beta.kubernetes.io/arch=arm64,beta.kubernetes.io/os=linux,kubernetes.io/arch=arm64,kubernetes.io/hostname=docker-desktop,kubernetes.io/os=linux,node-role.kubernetes.io/master=



% go run getos.go
darwin
https://kubernetes.io/zh/docs/reference/kubernetes-api/labels-annotations-taints/#kubernetes-io-os



kubernetes.io/os=linux 改成 darwin



也不对，因为运行在虚拟机器，所以linux 没有问题



% kubectl rollout history deployment kubernetes-dashboard -n kubernetes-dashboard
deployment.apps/kubernetes-dashboard
REVISION CHANGE-CAUSE
1
2



% kubectl rollout undo deployment kubernetes-dashboard –to-revision=1



–record 的作用是将当前命令记录到 revision 记录中，这样我们就可以知道每个 revison 对应的是哪个配置文件。通过 kubectl rollout history deployment httpd 查看 revison 历史记录



https://segmentfault.com/a/1190000020675199
% kubectl get pod kubernetes-dashboard-665f4c5ff-tp5sm -n kubernetes-dashboard -o yaml | kubectl replace –force -f -
pod “kubernetes-dashboard-665f4c5ff-tp5sm” deleted
pod/kubernetes-dashboard-665f4c5ff-tp5sm replaced



% kubectl delete pod dashboard-metrics-scraper-854fd5544b-gjbvh -n kubernetes-dashboard –force
warning: Immediate deletion does not wait for confirmation that the running resource has been terminated. The resource may continue to run on the cluster indefinitely.
pod “dashboard-metrics-scraper-854fd5544b-gjbvh” force deleted



% kubectl delete -f kubernetes-dashboard.v3.yaml
namespace “kubernetes-dashboard” deleted
serviceaccount “kubernetes-dashboard” deleted



https://blog.csdn.net/chenleiking/article/details/80197975



% kubectl get pods -n kubernetes-dashboard -o wide



已经全部删除了



% kubectl apply -f kubernetes-dashboard.yaml –record



% kubectl get pods -n kubernetes-dashboard -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
dashboard-metrics-scraper-7b59f7d4df-2vwmx 1/1 Running 0 76s 10.1.0.11 docker-desktop
kubernetes-dashboard-665f4c5ff-qz4h9 0/1 ContainerCreating 0 76s docker-desktop



应该是资源不够，加大内存问题解决



% kubectl get pods -n kubernetes-dashboard -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
dashboard-metrics-scraper-7b59f7d4df-2vwmx 1/1 Running 1 6m8s 10.1.0.17 docker-desktop
kubernetes-dashboard-665f4c5ff-qz4h9 1/1 Running 0 6m8s 10.1.0.16 docker-desktop



TOKEN=$(kubectl -n kube-system describe secret default| awk ‘$1==”token:”{print $2}’)
kubectl config set-credentials docker-for-desktop –token=”${TOKEN}”
echo $TOKEN



http://localhost:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:/proxy/#/overview?namespace=default



Category k8s