如何使用 kubectl 描述 Kube.netes 集群？

Question

I want to check the Kube.netes configuration - how many nodes, etc. I tried the following command.

kubectl describe cluster
error: the server doesn't have a resource type "cluster"

BTW, I tried to use the following command to check the AZ of the nodes of the pods. But it returns <none> for all the pods' nodes.

kubectl get pods -o=custom-columns=NAME:.metadata.name,ZONE:.metadata.labels.'topology\.Kubernetes\.io/zone'

How to use kubectl to find the AZs of the pods?

Answer 1

I could be missing the point of your question, but if you just need the nodes, you could do

kubectl get nodes

and then

kubectl describe node {node-name}

to get further details of an individual node

You could also combine the output from kubectl get nodes and either use jsonpath or jq to filter the information you need.

Answer 2

Here are my nodes showing zone info(made up) in the cluster:

kubectl get node -Ltopology.kubernetes.io/zone
NAME                            STATUS   ROLES           AGE   VERSION   ZONE
development-kube-controller-1   Ready    control-plane   48d   v1.24.6   zone
development-kube-worker-1       Ready    <none>          48d   v1.24.6   zone-A
development-kube-worker-2       Ready    <none>          48d   v1.24.6   zone-B

Using the awk command, the label topology.kube.netes.io/zone is merged with the name of the pods scheduled on that particular node.

NOTE : I have used lowercase k in the label key topology\.kube.netes\.io/zone ; however, in your case, it's uppercase K in the question. You might want to calibrate your command.

kubectl describe  node |awk '/topology.kubernetes.io\/zone/{zone=$1;next} /^  Namespace/{flag=1; getline; next} /^Allocated resources:/{flag=0} flag{print  $2, zone}' |column -t
calico-node-swz7j                                      topology.kubernetes.io/zone=zone
coredns-74d6c5659f-4mpcp                               topology.kubernetes.io/zone=zone
dns-autoscaler-59b8867c86-w4dls                        topology.kubernetes.io/zone=zone       
kubernetes-dashboard-648989c4b4-b4k7h                  topology.kubernetes.io/zone=zone-A
kubernetes-metrics-scraper-84bbbc8b75-x72pf            topology.kubernetes.io/zone=zone-A
nginx-proxy-development-kube-worker-1                  topology.kubernetes.io/zone=zone-A
nodelocaldns-xt6hr                                     topology.kubernetes.io/zone=zone-A
metallb-controller-94c85f6db-6j8j5                     topology.kubernetes.io/zone=zone-A
metallb-speaker-4fz99                                  topology.kubernetes.io/zone=zone-A
argocd-application-controller-0                        topology.kubernetes.io/zone=zone-B
argocd-applicationset-controller-5bff759d68-kk7tx      topology.kubernetes.io/zone=zone-B
argocd-dex-server-59c59b5d96-7z7th                     topology.kubernetes.io/zone=zone-B
argocd-notifications-controller-6df97c8577-26z9m       topology.kubernetes.io/zone=zone-B
argocd-redis-684fb8c6dd-bxb25                          topology.kubernetes.io/zone=zone-B
argocd-repo-server-79d8c5f7b4-fnh7g                    topology.kubernetes.io/zone=zone-B

PS: You can print $1 in the awk command to print the namespace, in case of filtering based on namespace is needed.

Answer 3

Try this command

kubectl cluster-info