Kubernetes with K9s

Introduction

In this comprehensive guide, we'll explore K9s, a terminal-based user interface that simplifies the management of Kubernetes resources. Whether you're a developer, operator, or DevOps professional, this tutorial will equip you with the knowledge and skills to leverage K9s to enhance your Kubernetes workflow.

Skills Graph

Introduction to K9s and Kubernetes

Kubernetes is a powerful open-source container orchestration platform that has become the de facto standard for managing and scaling containerized applications. K9s, short for "Kubernetes in 9 seconds," is a terminal-based user interface that provides a seamless and efficient way to interact with Kubernetes clusters.

K9s is designed to simplify the management of Kubernetes resources, making it easier for developers, operators, and DevOps teams to navigate and manage their Kubernetes environments. It provides a comprehensive set of features that allow users to view, interact with, and troubleshoot their Kubernetes resources directly from the command line.

In this tutorial, we will explore the key features and capabilities of K9s, and how it can be used to enhance your Kubernetes workflow. We will cover the installation and configuration of K9s, as well as the various ways you can navigate and manage your Kubernetes resources using this powerful tool.

By the end of this tutorial, you will have a solid understanding of how K9s can streamline your Kubernetes management tasks, allowing you to work more efficiently and effectively with your Kubernetes-based applications.

Installing and Configuring K9s

Installing K9s

K9s can be installed on various operating systems, including Linux, macOS, and Windows. In this tutorial, we will focus on the installation process for a Linux-based system.

To install K9s on a Linux system, you can use the following steps:

1. Download the latest K9s binary from the official GitHub repository: https://github.com/derailed/k9s/releases
2. Extract the downloaded file using the following command:

   tar -xzvf k9s_Linux_x86_64.tar.gz

3. Move the extracted k9s binary to a directory in your system's PATH, such as /usr/local/bin:

   sudo mv k9s /usr/local/bin/

4. Make the k9s binary executable:

   sudo chmod +x /usr/local/bin/k9s

Now that you have K9s installed, let's move on to configuring it.

Configuring K9s

K9s can be configured using a YAML configuration file located at ~/.k9s/config.yml. This file allows you to customize various aspects of the K9s user interface, such as the color scheme, keyboard shortcuts, and default resource views.

Here's an example configuration file:

k9s:
  refreshRate: 2
  maxConnections: 20
  view:
    logs:
      colorMode: light
      timestamps: true
    yaml:
      colorMode: dark
    ctx:
      colorMode: dark
  currentContext: default

In this example, we've set the following configurations:

• refreshRate: The interval (in seconds) at which K9s refreshes the Kubernetes resource information.
• maxConnections: The maximum number of concurrent connections K9s can make to the Kubernetes API server.
• view.logs.colorMode: The color mode for the log view.
• view.logs.timestamps: Whether to display timestamps in the log view.
• view.yaml.colorMode: The color mode for the YAML view.
• view.ctx.colorMode: The color mode for the context view.
• currentContext: The default Kubernetes context to use when launching K9s.

You can customize these settings to suit your preferences and workflow.

Navigating the K9s User Interface

Once you have K9s installed and configured, you can launch it from the command line by simply running the k9s command. This will open the K9s user interface, which is divided into several key components:

Overview

The K9s user interface consists of the following main components:

1. Cluster Information: Displays the current Kubernetes cluster context and namespace.
2. Resource View: Displays the list of Kubernetes resources, such as Pods, Deployments, Services, etc.
3. Resource Details: Provides detailed information about the selected Kubernetes resource.
4. Command Palette: Allows you to quickly execute various Kubernetes commands and actions.
5. Status Bar: Displays the current status of the Kubernetes cluster and provides access to additional features.

Keyboard Shortcuts

K9s provides a wide range of keyboard shortcuts to help you navigate and interact with the user interface more efficiently. Some of the commonly used shortcuts include:

You can customize these shortcuts by modifying the ~/.k9s/config.yml file.

Navigating Resource Views

K9s provides a comprehensive set of resource views, allowing you to easily navigate and manage your Kubernetes resources. You can switch between these views using the keyboard shortcuts or by using the command palette.

Some of the available resource views include:

• Pods
• Deployments
• Services
• Namespaces
• Nodes
• Persistent Volumes
• ConfigMaps
• Secrets

Within each resource view, you can use various commands and actions to interact with the resources, such as scaling, deleting, or describing them.

By mastering the K9s user interface and its keyboard shortcuts, you can significantly improve your productivity when working with Kubernetes.

Managing Kubernetes Resources with K9s

K9s provides a powerful set of features that allow you to effectively manage your Kubernetes resources. In this section, we'll explore some of the key capabilities of K9s in managing Kubernetes resources.

Viewing and Inspecting Resources

One of the primary functions of K9s is to provide a comprehensive view of your Kubernetes resources. You can navigate through the various resource views, such as Pods, Deployments, Services, and more, to inspect the current state of your applications.

For each resource, you can view detailed information, such as the resource's name, namespace, status, and any associated metadata. You can also use the <enter> key to open a detailed view of the selected resource, which includes YAML configuration, logs, and other relevant information.

Interacting with Resources

K9s allows you to perform various actions on your Kubernetes resources, such as scaling, deleting, and describing them. You can use the command palette or keyboard shortcuts to execute these actions.

For example, to scale a Deployment, you can:

1. Navigate to the Deployments view using the <ctrl+p> and <ctrl+n> shortcuts.
2. Select the Deployment you want to scale.
3. Press <ctrl+s> to open the scale dialog.
4. Enter the desired number of replicas and press <enter> to apply the change.

Similarly, you can delete a resource by selecting it and pressing <ctrl+d>.

Filtering and Searching

K9s provides powerful filtering and searching capabilities to help you quickly find and manage your Kubernetes resources. You can use the search bar at the top of the user interface to search for resources by name, namespace, or other attributes.

Additionally, you can use the <ctrl+f> shortcut to open the filter dialog, which allows you to apply more advanced filters based on resource type, status, and other criteria.

Monitoring and Troubleshooting

K9s also includes features to help you monitor and troubleshoot your Kubernetes applications. You can view the logs of a selected resource by pressing <ctrl+l>, and you can also view events and resource metrics directly within the K9s interface.

By leveraging the various resource management capabilities of K9s, you can streamline your Kubernetes workflow and improve the efficiency of your Kubernetes-based applications.

Advanced K9s Features and Customization

While the core functionality of K9s provides a comprehensive set of tools for managing Kubernetes resources, the tool also offers a range of advanced features and customization options to further enhance your workflow.

Keyboard Macros

K9s supports the creation of custom keyboard macros, which allow you to automate repetitive tasks and streamline your Kubernetes management processes. You can define macros in the ~/.k9s/config.yml file using the macro configuration section.

Here's an example of a macro that scales a Deployment to 3 replicas:

macro:
  scaleToThree:
    description: Scale Deployment to 3 replicas
    binding:
      - <ctrl+s>
      - 3
      - <enter>

In this example, the scaleToThree macro is defined with a description and a binding that simulates the keystrokes to scale a Deployment to 3 replicas.

Custom Resource Views

K9s allows you to create custom resource views, which can be useful for displaying specific Kubernetes resources or aggregating data from multiple resources. You can define these custom views in the ~/.k9s/config.yml file using the views configuration section.

Here's an example of a custom view that displays all Pods with the label app=myapp:

views:
  myapp-pods:
    title: MyApp Pods
    readOnly: true
    shortcuts:
      - /myapp-pods
    commands:
      get:
        args:
          - pods
        flags:
          - --selector=app=myapp

In this example, the myapp-pods view is defined with a title, a read-only flag, a keyboard shortcut, and a custom get command that filters Pods by the app=myapp label.

Plugins and Extensions

K9s supports the use of plugins and extensions, which can further enhance the tool's functionality. These plugins can provide additional features, such as custom resource views, integration with external tools, or even the ability to execute arbitrary Kubernetes commands.

You can find and install K9s plugins from the official K9s plugin repository: https://github.com/derailed/k9s-plugins

By leveraging the advanced features and customization options of K9s, you can tailor the tool to your specific Kubernetes management needs and improve your overall efficiency and productivity.

Troubleshooting and Best Practices

While K9s is designed to simplify the management of Kubernetes resources, there may be times when you encounter issues or need to troubleshoot problems. In this section, we'll cover some common troubleshooting techniques and best practices for using K9s effectively.

Troubleshooting

1. Connectivity Issues: If you're experiencing issues connecting to your Kubernetes cluster, ensure that your kubeconfig file is correctly configured and that you have the necessary permissions to access the cluster.

2. Resource Not Found: If you're unable to find a specific Kubernetes resource in K9s, check the following:

   • Ensure that you're in the correct namespace.
   • Use the search and filtering capabilities to locate the resource.
   • Verify that the resource actually exists in your Kubernetes cluster.

3. Unexpected Behavior: If you encounter unexpected behavior or errors in K9s, try the following:

   • Check the K9s logs for any error messages or clues about the issue.
   • Ensure that you're using the latest version of K9s, as newer versions may include bug fixes or improvements.
   • Try resetting the K9s configuration by deleting the ~/.k9s directory and restarting the tool.

4. Performance Issues: If you're experiencing performance issues, such as slow response times or high resource usage, consider the following:

   • Adjust the refreshRate and maxConnections settings in the ~/.k9s/config.yml file to optimize the tool's performance.
   • Limit the number of resources displayed in each view by using filtering and search capabilities.
   • Avoid opening too many resource details or logs at the same time, as this can impact performance.

Best Practices

1. Keep K9s Up-to-Date: Regularly update to the latest version of K9s to ensure that you have access to the latest features, bug fixes, and security updates.

2. Customize the Configuration: Tailor the K9s configuration to your specific needs by modifying the ~/.k9s/config.yml file. This includes setting custom keyboard shortcuts, color schemes, and default resource views.

3. Leverage Keyboard Shortcuts: Familiarize yourself with the available keyboard shortcuts in K9s to improve your productivity and efficiency when managing Kubernetes resources.

4. Use Filtering and Searching: Take advantage of the powerful filtering and searching capabilities in K9s to quickly locate and manage specific Kubernetes resources.

5. Integrate with Other Tools: Consider integrating K9s with other Kubernetes management tools or your existing DevOps workflows to streamline your overall Kubernetes operations.

6. Monitor Resource Usage: Keep an eye on the resource usage and performance of your Kubernetes cluster, and use K9s to help identify and troubleshoot any issues.

By following these troubleshooting tips and best practices, you can ensure that you get the most out of K9s and effectively manage your Kubernetes environments.

Summary

By the end of this tutorial, you will have a deep understanding of K9s and its capabilities, from installation and configuration to advanced features and customization. You'll learn how to effectively navigate the K9s user interface, manage Kubernetes resources, and troubleshoot common issues, all while following best practices for optimizing your Kubernetes operations with K9s.