Check your cluster

Check your cluster

Additional connection and service information information can be collected using the cluster-info command:

kubectl cluster-info

Kubernetes master is running at https://10.10.98.10:6443
KubeDNS is running at https://10.10.98.10:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

Here, the output is showing the endpoint for our Kubernetes master as well as the KubeDNS service endpoint.

To see information about each of the individual nodes that are members of your cluster with a wide output, use the get nodes command:

kubectl get nodes -o wide

NAME       STATUS   ROLES    AGE     VERSION   INTERNAL-IP   EXTERNAL-IP   OS-IMAGE             KERNEL-VERSION     CONTAINER-RUNTIME
master01   Ready    master   98m     v1.19.6   10.10.95.11   <none>        Ubuntu 20.04.1 LTS   5.4.0-48-generic   docker://19.3.14
worker01   Ready    <none>   21m     v1.19.6   10.10.95.21   <none>        Ubuntu 20.04.1 LTS   5.4.0-48-generic   docker://19.3.14
worker02   Ready    <none>   9m39s   v1.19.6   10.10.95.22   <none>        Ubuntu 20.04.1 LTS   5.4.0-48-generic   docker://19.3.14
worker03   Ready    <none>   8m14s   v1.19.6   10.10.95.23   <none>        Ubuntu 20.04.1 LTS   5.4.0-48-generic   docker://19.3.14

This lists the status, roles, connection information, and version numbers of the core software running on each of the nodes. If you need to perform maintenance on your cluster nodes or log in to debug an issue, this command can help provide the information you need.

Viewing Resource and Event Information

To get an overview of the namespaces available within a cluster, use the get namespaces command:

kubectl get namespaces

NAME              STATUS   AGE
calico-system     Active   67m
default           Active   99m
kube-node-lease   Active   99m
kube-public       Active   99m
kube-system       Active   99m
tigera-operator   Active   75m

This shows the namespace partitions defined within the current cluster.

To get an overview of all of the resources running on your cluster, across all namespaces, issue the following command:

kubectl get all --all-namespaces

<output_omitted>

The output displays the namespace each resource is deployed in as well as the resource name prefixed by the resource type (output_omitted in the examples shown above). Afterwards, information about the ready and running statuses of each resource helps determine if the processes are operating healthily.

To view the events associated with your resources, use the get events command:

kubectl get events --all-namespaces

<output_omitted>

This lists the most recent events logged by your resources, including the event message and the reason it was triggered.