This guide provides essential commands to check the status of various Kubernetes objects, including Pods, Nodes, Services, ConfigMaps, Secrets, StatefulSets, and Deployments. These commands will help you monitor the health and performance of your Kubernetes cluster.

Checking the status of Kubernetes objects allows you to verify that your applications are running as intended. It helps in identifying and troubleshooting issues, such as failed deployments, unresponsive services, or pods that are not in a ready state. Regular monitoring of these objects is critical for maintaining the health and performance of your Kubernetes cluster.

Checking Pod Status

What is a Pod?

A Pod is the smallest deployable unit in Kubernetes, representing a group of one or more application containers with shared storage/network resources and a specification for how to run the containers.

Command to Check Pod Status

kubectl get pods

Example Output:

$ kubectl get pods
NAME                        READY   STATUS             RESTARTS   AGE
nextgen-gw-0                0/3     Running            0          5s

  • READY: Indicates how many containers in the pod are ready.
  • STATUS: Shows the current status of the pod (e.g., Running, Pending, Failed).
  • RESTARTS: The number of times the containers in the pod have restarted.
  • AGE: How long the pod has been running.

Checking Node Status

What is a Node?

A Node is a physical or virtual machine in a Kubernetes cluster that runs one or more pods. Each Node is managed by the Kubernetes control plane, which automatically handles scheduling the pods across the Nodes.

Command to Check Node Status

kubectl get nodes

Example Output:

$ kubectl get nodes 
NAME          STATUS   ROLES    AGE     VERSION 
node1         Ready    <none>   5d20h   v1.18.2

  • STATUS: Should be Ready to indicate that the Node is functioning properly.
  • ROLES: Shows the roles assigned to the Node (e.g., control plane, worker).
  • AGE: Indicates how long the Node has been part of the cluster.
  • VERSION: Displays the Kubernetes version running on the Node.

Checking Kubernetes Services

What is a Service?

A Service in Kubernetes is an abstraction that defines a logical set of Pods and a policy by which to access them. Services enable the routing of traffic to the appropriate pods across the cluster.

Command to Check Service Status

kubectl get svc

Example Output:

$ kubectl get svc 
NAME         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)    AGE 
kubernetes   ClusterIP   10.96.0.1        <none>        443/TCP    7d

  • TYPE: Specifies how the service is exposed (e.g., ClusterIP, NodePort, LoadBalancer).
  • CLUSTER-IP: The internal IP address of the service.
  • EXTERNAL-IP: The external IP address (if the service is exposed outside the cluster).
  • PORT(S): The port(s) the service is exposed on.
  • AGE: Indicates how long the service has been running.

Checking ConfigMaps

What is a ConfigMaps?

A ConfigMap is used to store non-confidential configuration data in key-value pairs. ConfigMaps allow you to decouple environment-specific configurations from container images, making applications more portable.

Command to Check ConfigMaps Status

kubectl get cm

Example Output:

$ kubectl get cm 
NAME               DATA   AGE 
app-config         3      7d

  • DATA: Indicates the number of key-value pairs in the ConfigMap.
  • AGE: Shows how long the ConfigMap has been in the cluster.

Checking Secrets

What is a Secrets?

A Secret is used to store and manage sensitive information, such as passwords, tokens, or keys. Secrets are similar to ConfigMaps, but they are intended to hold confidential data.

Command to Check Secrets Status

kubectl get secrets

Example Output:

$ kubectl get secrets 
NAME                  TYPE                                  DATA   AGE 
default-token-abc123  kubernetes.io/service-account-token   3      7d

  • TYPE: Indicates the type of secret (e.g., Opaque, kubernetes.io/service-account-token).
  • DATA: The number of data entries (key-value pairs) in the secret.
  • AGE: Shows how long the secret has been in the cluster.

Checking StatefulSets

What is a StatefulSets?

A StatefulSet is a Kubernetes controller that manages the deployment and scaling of a set of Pods with unique, persistent identities. StatefulSets are used for applications that require stable storage and network identities, such as databases.

Command to Check StatefulSets Status

kubectl get statefulset

Example Output:

$ kubectl get statefulset 
NAME         READY   AGE 
web          1/1     7d

  • READY: Indicates how many replicas are ready.
  • AGE: Shows how long the StatefulSet has been running.