How to get Kubernetes cluster name from K8s API

Question

As stated in the title, is it possible to find out a K8s cluster name from the API? I looked around the API and could not find it.

Answer 1

kubectl config current-context does the trick (it outputs little bit more, like project name, region, etc., but it should give you the answer you need).

Answer 2

Unfortunately a cluster doesn't know its own name, or anything else that would uniquely identify it (K8s issue #44954). I wanted to know for helm issue #2055.

Update: A common workaround is to create a ConfigMap containing the cluster name and read that when required (#2055 comment 1244537799).

apiVersion: v1
kind: ConfigMap
metadata:
  name: cluster-info
  namespace: kube-system
data:
  cluster-name: foo

Answer 3

There is no way to get the name via K8s API. But here is a one-liner in case the name you have in your .kube/config file is enough for you (if you download it from your cloud provider the names should match):

kubectl config view --minify -o jsonpath='{.clusters[].name}'

Note 1: The --minify is key here so it will output the name of your current context only. There are other similar answers posted here but without the "minify" you will be listing other contexts in your config that might confuse you.

Note 2: The name in your .kube/config might not reflect the name in your cloud provider, if the file was autogenerated by the cloud provider the names should match, if you configured it manually you could have typed any name just for local config.

Note 3: Do not rely on kubectl config current-context this returns just the name of the context, not the name of the cluster.

Answer 4

I dont believe there is a k8s cluster name. This command could provide some nice informations

kubectl cluster-info

Answer 5

The question is not really well described. However, if this question is related to Google Container Engine then as coreypobrien mentioned the name of cluster is stored in custom metadata of nodes. From inside a node, run the following command and the output will be name of cluster:

curl http://metadata/computeMetadata/v1/instance/attributes/cluster-name -H "Metadata-Flavor: Google"

If you specify your use case, I might be able to extend my answer to cover it.

Answer 6

The kubernetes API doesn't know much about the GKE cluster name, but you can easily get the cluster name from the Google metatdata server like this

kubectl run curl --rm --restart=Never -it --image=appropriate/curl -- -H "Metadata-Flavor: Google" http://metadata.google.internal/computeMetadata/v1/instance/attributes/cluster-name

Answer 7

It is the same as getting the current config, but the below command gives clear output:

kubectl config view

Answer 8

This command will Check all possible clusters, as you know .KUBECONFIG may have multiple contexts

kubectl config view -o jsonpath='{"Cluster name\tServer\n"}{range .clusters[*]}{.name}{"\t"}{.cluster.server}{"\n"}{end}'

And you will get output like

Cluster name    Server
kubernetes      https://localhost:6443

Answer 9

For clusters that were installed using kubeadm, the configuration stored in the kubeadm-config configmap has the cluster name used when installing the cluster.

$ kubectl -n kube-system get configmap kubeadm-config -o yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: kubeadm-config
  namespace: kube-system
data:
  ClusterConfiguration: |
    clusterName: NAME_OF_CLUSTER

For clusters that are using CoreDNS for their DNS, the "cluster name" from kubeadm is also used as the domain suffix.

$ kubectl -n kube-system get configmap coredns -o yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: coredns
  namespace: kube-system
data:
  Corefile: |
    .:53 {
        kubernetes NAME_OF_CLUSTER.local in-addr.arpa ip6.arpa {

Answer 10

at-least for kubespray clusters, the following works for me

kubectl config current-context | cut -d '@' -f2

Answer 11

Well this returns precisely one thing, a cluster name

K8s: kubectl config view -o jsonpath='{.clusters[].name}{"\n"}'

Openshift: oc config view -o jsonpath='{.clusters[].name}{"\n"}'

Answer 12

$ kubectl config get-clusters --> get you the list of existing clusters

Answer 13

Using python k8s client. But this won't work with incluster_kubeconfig.

from kubernetes import config

cluster_context = config.kube_config.list_kube_config_contexts()
print (cluster_context)
([{'context': {'cluster': 'k01.test.use1.aws.platform.gov', 'user': 'k01-test'}, 'name': 'k01.test.use1.aws.platform.gov'}], {'context': {'cluster': 'k01.test.use1.aws.platform.gov', 'user': 'k01-test'}, 'name': 'k01.test.use1.aws.platform.gov'})

cluster_name = cluster_context[1]['context']['cluster']
print (cluster_name)
k01.test.use1.aws.platform.gov

Answer 14

Using kubectl command:

$ kubectl config get-clusters
NAME
kubernetes

Answer 15

kubectl config get-clusters
    
kubectl config get-contexts

Answer 16

There is a great tool called kubectx https://github.com/ahmetb/kubectx.

kubectx - lists all previously added clusters and highlights the currently used one. This is only one word to type instead of kubectl config current-context.

kubectx <cluster> - switches to a chosen cluster.

Moreover this tool comes also with kubens which does exactly the same for namespaces:

kubens - lists all namespaces and shows the current one,

kubens <namespace> - switches to a chosen namespace.