The Only Kubectl Commands Cheat Sheet You’ll Ever Need

In Kubernetes, kubectl is your go-to command-line tool. From creating and deleting pods to debugging and scaling deployments, kubectl is the primary way to manage all Kubernetes resources. This cheat sheet covers essential commands and explanations, so you can confidently work with Kubernetes clusters.

TL, DR;

Core kubectl Commands

The most foundational commands are essential for everyday tasks.

List Resources

Start by listing resources with kubectl get. You can view all Kubernetes resources, whether pods, services, or nodes.

# List all pods, services, and nodes across all namespaces
kubectl get pods --all-namespaces
kubectl get svc        # shorthand for services
kubectl get nodes

Describe Resources

Use kubectl describe to view metadata, events, and configuration details of resources, which is incredibly useful for debugging.

# Describe a specific pod in a namespace
kubectl describe pod <pod_name> -n <namespace-name>

Delete Resources

kubectl delete removes resources—be careful, as it’s irreversible. Specify resource types, namespaces, or names to avoid unintended deletions.

# Delete a specific pod in a namespace
kubectl delete pod <pod_name> -n <namespace-name>

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Using Selectors with field-selector

Select specific pods based on attributes like name, status, or labels.

# Get all running pods based on their status
kubectl get pods --field-selector=status.phase=Running

Working with Pods

Pods are the smallest deployable units and a core component of Kubernetes objects. Managing and debugging pods is fundamental to understanding application behavior.

1. Retrieve Pod Logs

Logs are invaluable for tracking application performance and error handling.

# Get logs for a specific pod in a namespace
kubectl logs <pod_name> -n <namespace-name>

2. Running Commands Inside Pods

Run interactive commands to troubleshoot inside a container.

# Execute commands within a pod's container
kubectl exec -it <pod_name> -- /bin/bash

3. Monitor CPU and Memory Usage

Get real-time data on CPU and memory usage with kubectl top. This command works for both nodes and pods.

# Monitor CPU and memory usage for a specific pod
kubectl top pod <pod_name> -n <namespace-name>

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Deployments and Rollouts

Deployments manage workloads by scaling applications, applying updates, and rolling back changes.

Creating a Deployment

Quickly set up a deployment using a container image.

# Create a deployment with a specified container image
kubectl create deployment <deployment_name> --image=<container_image>

Manage Rollouts

Rollouts help update images and configuration settings seamlessly.

# Update the container image in a deployment and check the rollout status
kubectl set image deployment/<deployment_name> <container_name>=<new_image>
kubectl rollout status deployment/<deployment_name>

Scaling Deployments

kubectl scale adjusts the number of replicas in a deployment, ensuring that applications can handle changes in demand.

# Scale a deployment to the desired number of replicas
kubectl scale deployment <deployment_name> --replicas=<desired_number>

Namespace Management

Namespaces in Kubernetes are like organizing folders on your computer. They allow you to separate environments and isolate resources.

Create a Namespace

Organize resources by creating namespaces for staging, testing, and production environments.

# Create a new namespace
kubectl create namespace <namespace-name>

List All Namespaces

Get an overview of all namespaces.

# List all namespaces in the cluster
kubectl get namespaces

Switch Namespace Context

Use the kubectl config command to set a default namespace context, simplifying commands.

# Set the current context to a specific namespace
kubectl config set-context --current --namespace=<namespace-name>

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Advanced Configurations and Resource Management

Efficiently manage cluster settings and resource configurations with commands that allow inspection and updates on the fly.

View Cluster Configurations

Display your active kubeconfig file that shows context, cluster information, and namespace preferences.

# View the active kubeconfig settings
kubectl config view

Edit Resources Directly

Use kubectl edit to make changes directly to resources. This command opens a text editor with the current YAML configuration.

# Edit a specific pod's configuration in a namespace
kubectl edit pod <pod_name> -n <namespace-name>

Annotate and Label Resources

Adding labels and annotations can be helpful for identification and filtering.

Add a label:

# Add a label to a specific pod
kubectl label pod <pod_name> env=production

Add an annotation:

# Add an annotation to a specific pod
kubectl annotate pod <pod_name> description="Backend pod for service A"

Cluster Management

Here’s how to gather information and monitor your Kubernetes environment to keep the cluster in shape.

Cluster Info

Quickly check API server endpoints and basic information.

# Display basic information about the cluster
kubectl cluster-info

Persistent Volumes

Persistent storage is essential for data that needs to outlast the lifecycle of a pod.

# Get a list of persistent volumes in the cluster
kubectl get persistentvolumes

Mark Nodes as Schedulable/Unschedulable

During maintenance, you can mark nodes as unschedulable to prevent new workloads from being assigned.

# Mark a node as unschedulable
kubectl cordon <node_name>

# Mark a node as schedulable again
kubectl uncordon <node_name>

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Monitoring and Port Forwarding

Use advanced commands to get resource data and test internal services.

Forward a Pod’s Port

Expose a pod’s port to your local machine for testing or debugging.

# Forward a pod's port to a local port
kubectl port-forward <pod_name> <local_port>:<remote_port> -n <namespace-name>

Monitor Resource Metrics

To see resource usage, such as CPU and memory, for nodes or pods, use kubectl top.

# Monitor resource metrics for nodes
kubectl top node

JSON and YAML Output

Display Kubernetes resource output in YAML or JSON formats, useful for saving configurations to files.

# Get a list of pods in YAML format
kubectl get pods -o yaml

Interacting with the Kubernetes API Server

Explore available resources in the Kubernetes API.

List API Resources

Display all available resource types in the API.

# List all resource types in the Kubernetes API
kubectl api-resources

Filter Output with JSONPath

Use JSONPath to pull specific fields from resource output.

# Get the names of all pods using JSONPath
kubectl get pods -o jsonpath='{.items[*].metadata.name}'

Conclusion

And there you have it! This cheat sheet is your handy guide to tackling Kubernetes tasks with ease. Remember, the best way to get comfortable with Kubernetes is to jump in and start experimenting.

FAQs

What is in kubectl commands?
kubectl commands encompass various operations you can perform on Kubernetes resources, including managing pods, services, deployments, namespaces, and more. Some common commands include kubectl get, kubectl create, kubectl delete, and kubectl describe.

How to practice Kubernetes commands?
You can practice Kubernetes commands by setting up a local cluster using tools like Minikube or Kind (Kubernetes in Docker). These environments allow you to experiment with kubectl commands without affecting a live production environment.

What is the command to get all running pods?
To list all running pods across all namespaces, you can use:

kubectl get pods --all-namespaces --field-selector=status.phase=Running

Which command is used to list all the Kubernetes objects?
To list all Kubernetes objects within a specific namespace, use:

kubectl get all -n <namespace-name>

To list all objects in all namespaces, add the --all-namespaces flag:

kubectl get all --all-namespaces

Can I Use Docker Without Kubernetes?
Yes, you can use Docker independently of Kubernetes. Docker is a platform for developing, shipping, and running applications inside containers, while Kubernetes is a container orchestration tool that helps manage and scale containerized applications.

Who Are These Kubectl Cheat Sheet Commands For?
These kubectl commands are for developers, system administrators, and DevOps professionals who work with Kubernetes to manage containerized applications, whether in development, testing, or production environments.

Do You Want a Career in DevOps?
If you're interested in automation, infrastructure management, and bridging development and operations, pursuing a career in DevOps can be rewarding. Proficiency in tools like kubectl and understanding Kubernetes can significantly enhance your qualifications.

What is a StatefulSet?
A StatefulSet is a Kubernetes workload API object designed for managing stateful applications. It provides guarantees about the ordering and uniqueness of pod deployment, making it suitable for applications requiring stable identities, persistent storage, and ordered deployments.

What is a Kubernetes Manifest File?
A Kubernetes manifest file is a YAML file that defines the desired state of a Kubernetes object, such as a pod, deployment, or service. It specifies configurations, including resource specifications, labels, and containers.

What are DaemonSets?
A DaemonSet ensures that a copy of a specific pod runs on all or a subset of nodes in a Kubernetes cluster. They are typically used for background tasks like logging and monitoring, ensuring that necessary services are always running on all designated nodes.

How can I create a deployment in Kubernetes using kubectl?
To create a deployment, use the following command:

kubectl create deployment <deployment_name> --image=<container_image>

What is the kubectl command to describe a specific node in a Kubernetes cluster?
To get detailed information about a specific node, use:

kubectl describe node <node_name>

What is the kubectl command to scale deployment in Kubernetes?
To scale a deployment to a desired number of replicas, use:

kubectl scale deployment <deployment_name> --replicas=<desired_number>

What is the difference between a Deployment and a StatefulSet in Kubernetes?
A Deployment is used for stateless applications, where pods are interchangeable, while a StatefulSet is used for stateful applications that require stable network identities and persistent storage. StatefulSets maintain the order and uniqueness of pods, while Deployments do not.

What is the purpose of a Service Account in Kubernetes?
A Service Account provides an identity for processes that run in a Pod. It is used to grant permissions and manage access to the Kubernetes API and other resources, enhancing security within your cluster.

What is a ConfigMap in Kubernetes?
A ConfigMap is a key-value store used to manage configuration data separately from application code. You can use ConfigMaps to store non-confidential data that your applications need at runtime.

What does the kubectl config use-context command do?
This command sets the current context in your kubeconfig file, which specifies the cluster, user, and namespace to be used in your kubectl commands.