Mastering kubectl: The Ultimate Guide to Kubernetes Command-Line Operations

November 25, 2024

English

Priyansh Khodiyar

In the realm of Kubernetes, the kubectl command-line tool stands as an indispensable ally for developers and operations engineers alike. Whether you're orchestrating a simple application or managing a complex, multi-tiered infrastructure, mastering kubectl is essential for efficient and effective Kubernetes management. This comprehensive guide delves deep into kubectl, exploring its myriad commands, syntax, use cases, and best practices to equip you with everything you need to navigate your Kubernetes clusters with confidence.

Introduction to kubectl
Getting Started with kubectl
- Installation
- Configuration
Basic kubectl Commands
Advanced kubectl Operations
kubectl Plugins and Extensions
- Installing Plugins
- Popular kubectl Plugins
Best Practices for Using kubectl
Common kubectl Errors and Troubleshooting
Use Cases and Practical Examples
Reference Tables
- Common kubectl Commands
- Resource Types and Their Shortcuts
Conclusion

Introduction to `kubectl`

At its core, kubectl is the command-line interface (CLI) for interacting with Kubernetes clusters. It allows users to deploy applications, inspect and manage cluster resources, and view logs, among other tasks. Whether you're provisioning new resources or troubleshooting existing ones, kubectl provides the tools necessary to maintain and operate your Kubernetes environments effectively.

Why kubectl Matters:

Control: Offers granular control over Kubernetes resources.
Efficiency: Streamlines operations through powerful command combinations.
Flexibility: Supports a wide range of tasks, from simple inspections to complex deployments.
Automation: Integrates seamlessly with scripts and automation tools, enhancing workflow efficiency.

Over the years, I've found that becoming proficient with kubectl significantly reduces the time spent managing clusters and allows for more focus on application development and optimization.

Getting Started with `kubectl`

Before diving into the myriad commands and functionalities, it's essential to set up kubectl correctly. This section covers the installation process and configuration steps to ensure you're ready to manage your Kubernetes clusters.

Installation

Prerequisites:

Operating System: kubectl is compatible with macOS, Linux, and Windows.
Kubernetes Cluster: Access to a running Kubernetes cluster (local or remote).

Installation Steps:

Using Package Managers:
- macOS (Homebrew):
```
brew install kubectl
```
- Ubuntu/Debian (apt):
```
sudo apt-get update
sudo apt-get install -y kubectl
```
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- Windows (Chocolatey):
```
choco install kubernetes-cli
```
Download Binary:

Visit the official Kubernetes release page and download the appropriate binary for your operating system. After downloading, move the binary to your PATH.

Verify Installation:

kubectl version --client

Expected Output:

Client Version: version.Info{Major:"1", Minor:"24", GitVersion:"v1.24.0", ...}

Configuration

Once installed, kubectl needs to be configured to communicate with your Kubernetes cluster. This is typically done via the kubeconfig file.

Steps:

Obtain kubeconfig:

If you're using a cloud provider like Google Kubernetes Engine (GKE), Amazon Elastic Kubernetes Service (EKS), or Azure Kubernetes Service (AKS), you can obtain the kubeconfig through their respective CLIs.
- GKE Example:
```
gcloud container clusters get-credentials [CLUSTER_NAME] --zone [ZONE] --project [PROJECT_ID]
```
Set KUBECONFIG Environment Variable (Optional):

If your kubeconfig is not located at the default path (~/.kube/config), set the KUBECONFIG environment variable:
```
export KUBECONFIG=/path/to/your/kubeconfig
```

Verify Configuration:

kubectl cluster-info

Expected Output:

Kubernetes control plane is running at https://<master-ip>
CoreDNS is running at https://<master-ip>/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

Basic `kubectl` Commands

Mastering the basics is crucial before moving on to more advanced operations. This section covers fundamental kubectl commands that form the backbone of Kubernetes management.

Viewing Cluster Information

View Cluster Info:
```
kubectl cluster-info
```
Description: Displays the Kubernetes master and services information.

View Nodes:

kubectl get nodes

Description: Lists all nodes in the cluster along with their status, roles, age, and version.

Sample Output:

NAME            STATUS   ROLES    AGE     VERSION
node-1          Ready    master   10d     v1.24.0
node-2          Ready    <none>   10d     v1.24.0
node-3          Ready    <none>   10d     v1.24.0

Managing Pods

List All Pods:
```
kubectl get pods
```
Description: Retrieves a list of all pods in the current namespace.
List Pods Across All Namespaces:
```
kubectl get pods --all-namespaces
```
Description: Displays pods from every namespace, providing a comprehensive view.
Describe a Pod:
```
kubectl describe pod [POD_NAME]
```
Description: Provides detailed information about a specific pod, including events, containers, and resource usage.
Delete a Pod:
```
kubectl delete pod [POD_NAME]
```
Description: Removes a specified pod from the cluster.

Managing Deployments

List Deployments:
```
kubectl get deployments
```
Description: Displays all deployments in the current namespace, showing replicas, availability, and strategy.

Create a Deployment:

kubectl create deployment [DEPLOYMENT_NAME] --image=[IMAGE_NAME]

Example:

kubectl create deployment nginx-deployment --image=nginx:1.14.2

Update a Deployment:

kubectl set image deployment/[DEPLOYMENT_NAME] [CONTAINER_NAME]=[NEW_IMAGE]

Example:

kubectl set image deployment/nginx-deployment nginx=nginx:1.16.0

Delete a Deployment:
```
kubectl delete deployment [DEPLOYMENT_NAME]
```
Description: Removes a specified deployment and its associated pods.

Managing Services

List Services:
```
kubectl get services
```
Description: Lists all services in the current namespace, showing type, cluster IP, external IP, ports, and age.

Create a Service:

kubectl expose deployment [DEPLOYMENT_NAME] --type=[SERVICE_TYPE] --port=[PORT_NUMBER]

Example:

kubectl expose deployment nginx-deployment --type=LoadBalancer --port=80

Delete a Service:
```
kubectl delete service [SERVICE_NAME]
```
Description: Removes a specified service from the cluster.

Advanced `kubectl` Operations

With a firm grasp of the basics, it's time to explore more sophisticated kubectl operations that empower you to manage Kubernetes clusters with greater precision and efficiency.

Using `kubectl` with YAML Manifests

YAML manifests provide a declarative way to define Kubernetes resources. Managing these manifests with kubectl allows for version-controlled deployments and easy replication across environments.

Apply a YAML Manifest:

kubectl apply -f [FILE_NAME].yaml

Example:

kubectl apply -f deployment.yaml

Create Resources from a Directory:

kubectl apply -f [DIRECTORY_PATH]/

Example:

kubectl apply -f ./k8s-configs/

Delete Resources from a YAML Manifest:

kubectl delete -f [FILE_NAME].yaml

Example:

kubectl delete -f deployment.yaml

Labeling and Selecting Resources

Labels are key-value pairs attached to Kubernetes objects, facilitating organization and selection.

Add a Label to a Resource:

kubectl label [RESOURCE_TYPE] [RESOURCE_NAME] [KEY]=[VALUE]

Example:

kubectl label pod my-pod environment=production

List Resources with a Specific Label:

kubectl get [RESOURCE_TYPE] -l [KEY]=[VALUE]

Example:

kubectl get pods -l environment=production

Remove a Label from a Resource:

kubectl label [RESOURCE_TYPE] [RESOURCE_NAME] [KEY]-

Example:

kubectl label pod my-pod environment-

Scaling Applications

Scaling is a fundamental aspect of Kubernetes, allowing applications to handle varying loads seamlessly.

Scale a Deployment:

kubectl scale deployment [DEPLOYMENT_NAME] --replicas=[NUMBER_OF_REPLICAS]

Example:

kubectl scale deployment nginx-deployment --replicas=5

Autoscale a Deployment:

kubectl autoscale deployment [DEPLOYMENT_NAME] --min=[MIN_REPLICAS] --max=[MAX_REPLICAS] --cpu-percent=[CPU_THRESHOLD]

Example:

kubectl autoscale deployment nginx-deployment --min=2 --max=10 --cpu-percent=80

Rolling Updates and Rollbacks

Maintaining application uptime during updates is critical. Kubernetes facilitates rolling updates and easy rollbacks to ensure seamless transitions.

Perform a Rolling Update:

kubectl set image deployment/[DEPLOYMENT_NAME] [CONTAINER_NAME]=[NEW_IMAGE]

Example:

kubectl set image deployment/nginx-deployment nginx=nginx:1.16.0

View Rollout Status:

kubectl rollout status deployment/[DEPLOYMENT_NAME]

Example:

kubectl rollout status deployment/nginx-deployment

Rollback to a Previous Revision:

kubectl rollout undo deployment/[DEPLOYMENT_NAME]

Example:

kubectl rollout undo deployment/nginx-deployment

Accessing Logs and Debugging

Understanding what's happening inside your pods is essential for troubleshooting and optimization.

View Logs of a Pod:

kubectl logs [POD_NAME]

Example:

kubectl logs my-pod

View Logs of a Specific Container:

kubectl logs [POD_NAME] -c [CONTAINER_NAME]

Example:

kubectl logs my-pod -c nginx

Stream Logs in Real-Time:

kubectl logs -f [POD_NAME]

Example:

kubectl logs -f my-pod

Execute a Command Inside a Pod:

kubectl exec -it [POD_NAME] -- [COMMAND]

Example:

kubectl exec -it my-pod -- /bin/bash

`kubectl` Plugins and Extensions

Enhancing kubectl with plugins can significantly boost your productivity and extend its capabilities beyond default offerings.

Installing Plugins

kubectl supports a plugin architecture, allowing you to add custom commands. Plugins are simply executable files that follow the naming convention kubectl-<plugin-name>.

Steps to Install a Plugin:

Download or Create the Plugin:

Obtain the plugin executable or develop your own based on your needs.

Move the Plugin to Your PATH:

mv kubectl-myplugin /usr/local/bin/kubectl-myplugin
chmod +x /usr/local/bin/kubectl-myplugin

Verify Installation:
```
kubectl myplugin
```

Popular `kubectl` Plugins

kubectl-plugins: A collection of useful plugins for various tasks.
kubectl-tree: Visualizes the resource hierarchy in a tree format.

Installation Example:
```
kubectl krew install tree
```
Usage:
```
kubectl tree deployment/nginx-deployment
```
kubectl-neat: Cleans up the output by removing unnecessary fields.

Installation Example:
```
kubectl krew install neat
```
Usage:
```
kubectl get pods -o yaml | kubectl neat
```

Note: krew is a plugin manager for kubectl that simplifies the installation and management of plugins. You can install krew by following the official installation guide.

Best Practices for Using `kubectl`

Adhering to best practices ensures that your use of kubectl is both efficient and secure, minimizing errors and enhancing productivity.

Efficient Command Usage

Use Aliases:

Simplify frequently used commands by creating aliases. For example:
```
alias k='kubectl'
alias kgp='kubectl get pods'
alias kdp='kubectl describe pod'
```
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UTF-8
Leverage Auto-Completion:

Enable shell auto-completion to speed up command entry and reduce errors.

Bash Example:
```
source <(kubectl completion bash)
echo "source <(kubectl completion bash)" >> ~/.bashrc
```
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UTF-8
Use Output Formats:

Tailor command outputs to your needs using formats like JSON, YAML, or custom columns.

Example:
```
kubectl get pods -o wide
kubectl get deployments -o json
kubectl get services -o yaml
```
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Automation and Scripting

Integrate kubectl commands into scripts to automate repetitive tasks, ensuring consistency and saving time.

Example: Automated Deployment Script

#!/bin/bash

DEPLOYMENT_NAME="nginx-deployment"
IMAGE_VERSION="1.16.0"

echo "Updating deployment $DEPLOYMENT_NAME to image nginx:$IMAGE_VERSION"
kubectl set image deployment/$DEPLOYMENT_NAME nginx=nginx:$IMAGE_VERSION
kubectl rollout status deployment/$DEPLOYMENT_NAME

Tips:

Error Handling: Incorporate checks to handle failures gracefully.

kubectl set image deployment/$DEPLOYMENT_NAME nginx=nginx:$IMAGE_VERSION || { echo "Update failed"; exit 1; }

Parameterization: Use variables for flexibility and reusability.

Security Considerations

Ensuring the security of your Kubernetes clusters and kubectl operations is paramount.

Protect kubeconfig: Your kubeconfig file contains sensitive information. Ensure it's secured with appropriate file permissions.
```
chmod 600 ~/.kube/config
```
Use RBAC Effectively: Implement Role-Based Access Control to restrict permissions based on user roles and responsibilities.
Audit and Monitor: Regularly audit kubectl usage and monitor for suspicious activities using tools like Kubernetes Audit Logs.

Common `kubectl` Errors and Troubleshooting

Encountering errors while using kubectl is common, especially when dealing with complex Kubernetes environments. Understanding these errors and their solutions is crucial for maintaining smooth operations.

Authentication and Authorization Issues

Error: You must be logged in to the server (Unauthorized)

Cause: Incorrect or missing credentials in the kubeconfig file.

Solution:
- Verify the kubeconfig file path and content.
- Ensure that the user has the necessary permissions.
- Refresh or update credentials if expired.
Error: Error from server (Forbidden): <resource> is forbidden

Cause: Insufficient RBAC permissions for the user.

Solution:
- Check the current user's roles and permissions.
- Update RBAC policies to grant necessary access.

Resource Not Found

Error: Error from server (NotFound): pods "<POD_NAME>" not found

Cause: The specified pod does not exist in the current namespace.

Solution:
- Verify the pod name and namespace.
- Use kubectl get pods --all-namespaces to search across namespaces.

Timeouts and Connectivity Problems

Error: The connection to the server <URL> was refused - did you specify the right host or port?

Cause: Network issues or incorrect API server URL.

Solution:
- Check network connectivity to the Kubernetes API server.
- Validate the API server URL in the kubeconfig file.
Error: Timed out waiting for the condition

Cause: Deployment or resource creation is taking longer than expected.

Solution:
- Investigate the status of the resource using kubectl describe.
- Check for resource constraints or pod scheduling issues.

Use Cases and Practical Examples

Understanding practical applications of kubectl commands enhances your ability to manage Kubernetes clusters effectively. Here are several real-world scenarios showcasing how to utilize kubectl in various situations.

Deploying an Application

Scenario: Deploy a simple Nginx web server to your Kubernetes cluster.

Steps:

Create a Deployment:

kubectl create deployment nginx-deployment --image=nginx:1.14.2

Expose the Deployment as a Service:

kubectl expose deployment nginx-deployment --type=LoadBalancer --port=80

Verify the Deployment and Service:
```
kubectl get deployments
kubectl get services
```
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Outcome: A running Nginx application accessible via the assigned external IP.

Updating an Application

Scenario: Update the Nginx deployment to a newer version without downtime.

Steps:

Set the New Image Version:

kubectl set image deployment/nginx-deployment nginx=nginx:1.16.0

Monitor the Rollout Status:

kubectl rollout status deployment/nginx-deployment

Outcome: The Nginx application updates to version 1.16.0 seamlessly, maintaining availability.

Scaling a Deployment

Scenario: Scale the Nginx deployment to handle increased traffic.

Steps:

Scale the Deployment:

kubectl scale deployment/nginx-deployment --replicas=5

Verify the Scaling:
```
kubectl get deployments
```

Outcome: The Nginx deployment scales to 5 replicas, distributing the load across multiple pods.

Monitoring Resource Usage

Scenario: Monitor CPU and memory usage of pods in the default namespace.

Steps:

View Resource Usage:

kubectl top pods

Sample Output:

NAME                      CPU(cores)   MEMORY(bytes)
nginx-deployment-abcde    10m          50Mi
nginx-deployment-fghij    15m          60Mi

Outcome: Real-time insights into resource consumption, enabling informed scaling decisions.

Debugging a Failing Pod

Scenario: Investigate why a pod is not running correctly.

Steps:

Describe the Pod:
```
kubectl describe pod [POD_NAME]
```
View Pod Logs:
```
kubectl logs [POD_NAME]
```

Execute a Shell in the Pod:

kubectl exec -it [POD_NAME] -- /bin/bash

Outcome: Detailed information and access to the pod's environment facilitate effective troubleshooting.

Reference Tables

Common `kubectl` Commands

Command	Description	Example
`kubectl get pods`	List all pods in the current namespace	`kubectl get pods`
`kubectl describe pod [POD_NAME]`	Detailed information about a specific pod	`kubectl describe pod my-pod`
`kubectl logs [POD_NAME]`	Retrieve logs from a pod	`kubectl logs my-pod`
`kubectl exec -it [POD_NAME] -- /bin/bash`	Open a shell inside a running pod	`kubectl exec -it my-pod -- /bin/bash`
`kubectl create deployment [NAME] --image=[IMAGE]`	Create a new deployment	`kubectl create deployment nginx --image=nginx:1.14.2`
`kubectl expose deployment [NAME] --type=[TYPE] --port=[PORT]`	Expose a deployment as a service	`kubectl expose deployment nginx --type=LoadBalancer --port=80`
`kubectl set image deployment/[DEPLOYMENT_NAME] [CONTAINER_NAME]=[NEW_IMAGE]`	Update container image in a deployment	`kubectl set image deployment/nginx nginx=nginx:1.16.0`
`kubectl scale deployment/[DEPLOYMENT_NAME] --replicas=[NUMBER]`	Scale a deployment	`kubectl scale deployment/nginx --replicas=5`
`kubectl rollout status deployment/[DEPLOYMENT_NAME]`	Monitor rollout status	`kubectl rollout status deployment/nginx`
`kubectl delete [RESOURCE_TYPE] [RESOURCE_NAME]`	Delete a specific resource	`kubectl delete pod my-pod`
`kubectl apply -f [FILE].yaml`	Apply a YAML configuration	`kubectl apply -f deployment.yaml`
`kubectl delete -f [FILE].yaml`	Delete resources defined in a YAML file	`kubectl delete -f deployment.yaml`

Resource Types and Their Shortcuts

Resource Type	Full Command	Shortcut
Pod	`kubectl get pods`	`kubectl get po`
Deployment	`kubectl get deployments`	`kubectl get deploy`
Service	`kubectl get services`	`kubectl get svc`
ReplicaSet	`kubectl get replicasets`	`kubectl get rs`
Namespace	`kubectl get namespaces`	`kubectl get ns`
ConfigMap	`kubectl get configmaps`	`kubectl get cm`
Secret	`kubectl get secrets`	`kubectl get sec`
Node	`kubectl get nodes`	`kubectl get no`
PersistentVolume	`kubectl get persistentvolumes`	`kubectl get pv`
PersistentVolumeClaim	`kubectl get persistentvolumeclaims`	`kubectl get pvc`
Ingress	`kubectl get ingress`	`kubectl get ing`

Best Practices for Secure GitOps Workflows

While kubectl is a powerful tool, ensuring its secure and efficient usage is paramount. Implementing best practices not only enhances security but also streamlines operations, reducing the likelihood of errors and downtime.

Efficient Command Usage

Use Aliases: Simplify frequently used commands by creating aliases.

Example:
```
alias k='kubectl'
alias kgp='kubectl get pods'
alias kdp='kubectl describe pod'
```
Terminal
Lines: 3
UTF-8
Leverage Auto-Completion: Enable shell auto-completion to speed up command entry and minimize typos.

Bash Example:
```
source <(kubectl completion bash)
echo "source <(kubectl completion bash)" >> ~/.bashrc
```
Terminal
Lines: 2
UTF-8
Customize Output Formats: Use -o flag to specify output formats like JSON, YAML, or custom columns.

Example:
```
kubectl get pods -o wide
kubectl get services -o json
kubectl get deployments -o yaml
```
Terminal
Lines: 3
UTF-8

Automation and Scripting

Automate repetitive tasks using shell scripts or automation tools to enhance efficiency and ensure consistency.

Example: Automated Deployment Script

#!/bin/bash

DEPLOYMENT_NAME="nginx-deployment"
IMAGE_VERSION="1.16.0"

echo "Updating deployment $DEPLOYMENT_NAME to image nginx:$IMAGE_VERSION"
kubectl set image deployment/$DEPLOYMENT_NAME nginx=nginx:$IMAGE_VERSION
kubectl rollout status deployment/$DEPLOYMENT_NAME

Tips:

Error Handling: Incorporate checks to handle failures gracefully.

kubectl set image deployment/$DEPLOYMENT_NAME nginx=nginx:$IMAGE_VERSION || { echo "Update failed"; exit 1; }

Parameterization: Use variables for flexibility and reusability.

Security Considerations

Securing your kubectl usage is crucial to protect your Kubernetes clusters and resources.

Protect kubeconfig: Your kubeconfig file contains sensitive information. Ensure it has appropriate file permissions.
```
chmod 600 ~/.kube/config
```
Use RBAC Effectively: Implement Role-Based Access Control to restrict user permissions based on roles and responsibilities.
Audit and Monitor: Regularly audit kubectl usage and monitor for suspicious activities using Kubernetes Audit Logs and monitoring tools like Prometheus and Grafana.

Common `kubectl` Errors and Troubleshooting

Navigating Kubernetes can be challenging, and encountering errors while using kubectl is inevitable. Understanding common errors and their solutions is essential for maintaining a healthy cluster environment.

Authentication and Authorization Issues

Error: You must be logged in to the server (Unauthorized)

Cause: Incorrect or missing credentials in the kubeconfig file.

Solution:
- Verify the kubeconfig file path and content.
- Ensure the user has the necessary permissions.
- Refresh or update credentials if expired.
Error: Error from server (Forbidden): <resource> is forbidden

Cause: Insufficient RBAC permissions for the user.

Solution:
- Check the current user's roles and permissions.
- Update RBAC policies to grant necessary access.

Resource Not Found

Error: Error from server (NotFound): pods "<POD_NAME>" not found

Cause: The specified pod does not exist in the current namespace.

Solution:
- Verify the pod name and namespace.
- Use kubectl get pods --all-namespaces to search across namespaces.

Timeouts and Connectivity Problems

Error: The connection to the server <URL> was refused - did you specify the right host or port?

Cause: Network issues or incorrect API server URL.

Solution:
- Check network connectivity to the Kubernetes API server.
- Validate the API server URL in the kubeconfig file.
Error: Timed out waiting for the condition

Cause: Deployment or resource creation is taking longer than expected.

Solution:
- Investigate the status of the resource using kubectl describe.
- Check for resource constraints or pod scheduling issues.

Use Cases and Practical Examples

Understanding how to apply kubectl commands in real-world scenarios enhances your ability to manage Kubernetes clusters effectively. Below are several practical examples demonstrating the power and versatility of kubectl.

Deploying an Application

Scenario: Deploy a simple Nginx web server to your Kubernetes cluster.

Steps:

Create a Deployment:

kubectl create deployment nginx-deployment --image=nginx:1.14.2

Expose the Deployment as a Service:

kubectl expose deployment nginx-deployment --type=LoadBalancer --port=80

Verify the Deployment and Service:
```
kubectl get deployments
kubectl get services
```
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Outcome: A running Nginx application accessible via the assigned external IP.

Updating an Application

Scenario: Update the Nginx deployment to a newer version without downtime.

Steps:

Set the New Image Version:

kubectl set image deployment/nginx-deployment nginx=nginx:1.16.0

Monitor the Rollout Status:

kubectl rollout status deployment/nginx-deployment

Outcome: The Nginx application updates to version 1.16.0 seamlessly, maintaining availability.

Scaling a Deployment

Scenario: Scale the Nginx deployment to handle increased traffic.

Steps:

Scale the Deployment:

kubectl scale deployment/nginx-deployment --replicas=5

Verify the Scaling:
```
kubectl get deployments
```

Outcome: The Nginx deployment scales to 5 replicas, distributing the load across multiple pods.

Monitoring Resource Usage

Scenario: Monitor CPU and memory usage of pods in the default namespace.

Steps:

View Resource Usage:

kubectl top pods

Sample Output:

NAME                      CPU(cores)   MEMORY(bytes)
nginx-deployment-abcde    10m          50Mi
nginx-deployment-fghij    15m          60Mi

Outcome: Real-time insights into resource consumption, enabling informed scaling decisions.

Debugging a Failing Pod

Scenario: Investigate why a pod is not running correctly.

Steps:

Describe the Pod:
```
kubectl describe pod [POD_NAME]
```
View Pod Logs:
```
kubectl logs [POD_NAME]
```

Execute a Shell in the Pod:

kubectl exec -it [POD_NAME] -- /bin/bash

Outcome: Detailed information and access to the pod's environment facilitate effective troubleshooting.

Reference Tables

Common `kubectl` Commands

Command	Description	Example
`kubectl get pods`	List all pods in the current namespace	`kubectl get pods`
`kubectl describe pod [POD_NAME]`	Detailed information about a specific pod	`kubectl describe pod my-pod`
`kubectl logs [POD_NAME]`	Retrieve logs from a pod	`kubectl logs my-pod`
`kubectl exec -it [POD_NAME] -- /bin/bash`	Open a shell inside a running pod	`kubectl exec -it my-pod -- /bin/bash`
`kubectl create deployment [NAME] --image=[IMAGE]`	Create a new deployment	`kubectl create deployment nginx --image=nginx:1.14.2`
`kubectl expose deployment [NAME] --type=[TYPE] --port=[PORT]`	Expose a deployment as a service	`kubectl expose deployment nginx --type=LoadBalancer --port=80`
`kubectl set image deployment/[DEPLOYMENT_NAME] [CONTAINER_NAME]=[NEW_IMAGE]`	Update container image in a deployment	`kubectl set image deployment/nginx nginx=nginx:1.16.0`
`kubectl scale deployment/[DEPLOYMENT_NAME] --replicas=[NUMBER]`	Scale a deployment	`kubectl scale deployment/nginx --replicas=5`
`kubectl rollout status deployment/[DEPLOYMENT_NAME]`	Monitor rollout status	`kubectl rollout status deployment/nginx`
`kubectl delete [RESOURCE_TYPE] [RESOURCE_NAME]`	Delete a specific resource	`kubectl delete pod my-pod`
`kubectl apply -f [FILE].yaml`	Apply a YAML configuration	`kubectl apply -f deployment.yaml`
`kubectl delete -f [FILE].yaml`	Delete resources defined in a YAML file	`kubectl delete -f deployment.yaml`

Resource Types and Their Shortcuts

Resource Type	Full Command	Shortcut
Pod	`kubectl get pods`	`kubectl get po`
Deployment	`kubectl get deployments`	`kubectl get deploy`
Service	`kubectl get services`	`kubectl get svc`
ReplicaSet	`kubectl get replicasets`	`kubectl get rs`
Namespace	`kubectl get namespaces`	`kubectl get ns`
ConfigMap	`kubectl get configmaps`	`kubectl get cm`
Secret	`kubectl get secrets`	`kubectl get sec`
Node	`kubectl get nodes`	`kubectl get no`
PersistentVolume	`kubectl get persistentvolumes`	`kubectl get pv`
PersistentVolumeClaim	`kubectl get persistentvolumeclaims`	`kubectl get pvc`
Ingress	`kubectl get ingress`	`kubectl get ing`

Conclusion

Navigating the complexities of Kubernetes becomes significantly more manageable with a thorough understanding of kubectl. This command-line tool serves as the primary interface for interacting with Kubernetes clusters, offering a vast array of commands that cater to both basic and advanced operational needs. By mastering kubectl, you empower yourself to deploy applications efficiently, manage resources effectively, and troubleshoot issues with precision.

Throughout this guide, we've explored essential commands, advanced operations, plugins, best practices, and troubleshooting techniques. Whether you're a Kubernetes novice or a seasoned professional, integrating these practices into your workflow will enhance your ability to manage and scale your Kubernetes environments confidently.

Key Takeaways:

Foundation Matters: Start with mastering basic kubectl commands to build a strong operational foundation.
Leverage YAML Manifests: Adopt a declarative approach using YAML manifests for consistent and repeatable deployments.
Enhance Efficiency: Utilize aliases, auto-completion, and output formatting to streamline your command-line interactions.
Prioritize Security: Implement robust security measures, including secret management, RBAC, and policy enforcement, to protect your clusters.
Embrace Automation: Automate repetitive tasks and integrate kubectl commands into scripts to boost productivity and reduce errors.
Stay Informed: Continuously learn and adapt by exploring advanced commands, plugins, and best practices to stay ahead in the Kubernetes landscape.

As Kubernetes continues to evolve, so does kubectl. Staying updated with the latest enhancements and community-driven plugins ensures that you harness the full potential of this powerful tool, driving operational excellence and fostering a resilient, scalable infrastructure.

Happy Kubernetes journey! May your deployments be smooth, your clusters robust, and your kubectl commands ever accurate.

Written by Priyansh Khodiyar

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Priyansh is the founder of UnYAML and a software engineer with a passion for writing. He has good experience with writing and working around DevOps tools and technologies, APMs, Kubernetes APIs, etc and loves to share his knowledge with others.

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Priyansh Khodiyar

Table of Contents

Introduction to kubectl

Getting Started with kubectl

Installation

Configuration

Basic kubectl Commands

Viewing Cluster Information

Managing Pods

Managing Deployments

Managing Services

Advanced kubectl Operations

Using kubectl with YAML Manifests

Labeling and Selecting Resources

Scaling Applications

Rolling Updates and Rollbacks

Accessing Logs and Debugging

kubectl Plugins and Extensions

Installing Plugins

Popular kubectl Plugins

Best Practices for Using kubectl

Efficient Command Usage

Automation and Scripting

Security Considerations

Common kubectl Errors and Troubleshooting

Authentication and Authorization Issues

Resource Not Found

Timeouts and Connectivity Problems

Use Cases and Practical Examples

Deploying an Application

Updating an Application

Scaling a Deployment

Monitoring Resource Usage

Debugging a Failing Pod

Reference Tables

Common kubectl Commands

Resource Types and Their Shortcuts

Best Practices for Secure GitOps Workflows

Efficient Command Usage

Automation and Scripting

Security Considerations

Common kubectl Errors and Troubleshooting

Authentication and Authorization Issues

Resource Not Found

Timeouts and Connectivity Problems

Use Cases and Practical Examples

Deploying an Application

Updating an Application

Scaling a Deployment

Monitoring Resource Usage

Debugging a Failing Pod

Reference Tables

Common kubectl Commands

Resource Types and Their Shortcuts

Conclusion

Written by Priyansh Khodiyar

Introduction to `kubectl`

Getting Started with `kubectl`

Basic `kubectl` Commands

Advanced `kubectl` Operations

Using `kubectl` with YAML Manifests

`kubectl` Plugins and Extensions

Popular `kubectl` Plugins

Best Practices for Using `kubectl`

Common `kubectl` Errors and Troubleshooting

Common `kubectl` Commands

Common `kubectl` Errors and Troubleshooting

Common `kubectl` Commands