How to use the command 'kind' (with examples)

The kind command is a powerful tool designed to run local Kubernetes clusters using Docker container “nodes.” It was initially created to facilitate testing Kubernetes itself but has since grown to be useful for local development environments and continuous integration workflows. The tool allows developers to quickly spin up and tear down Kubernetes clusters, retrieve information, and export configurations or logs, all on a local machine. This guide will illustrate the use cases of the kind command with practical examples.

Use case 1: Create a local Kubernetes cluster

Code:

kind create cluster --name cluster_name

Motivation:

Creating a local Kubernetes cluster is an essential first step for developers looking to test and develop applications in a Kubernetes environment without requiring a full-fledged cloud setup. This local setup allows developers to verify that their applications can be deployed in Kubernetes and test configurations in an isolated environment, which can be crucial for debugging and iterative development.

Explanation:

• kind: The command to execute the ‘kind’ tool.
• create cluster: Sub-command to initiate the creation of a new Kubernetes cluster.
• --name cluster_name: This flag specifies the unique name for this local cluster. It allows for easy identification and management of multiple clusters, especially in a development environment where you might need distinct clusters for different projects or purposes.

Example Output:

Creating cluster "cluster_name" ...
✓ Ensuring node image (kindest/node:v1.21.1) 🖼  ...
✓ Preparing nodes 📦  ...
✓ Writing configuration 📜  ...
✓ Starting control-plane 🕹️  ...
✓ Installing CNI 🔌  ...
✓ Installing StorageClass 💾  ...
Set kubectl context to "kind-cluster_name"
You can now use your cluster with:

kubectl cluster-info --context kind-cluster_name

Have a nice day! 👋

Use case 2: Delete one or more clusters

Code:

kind delete clusters cluster_name

Motivation:

Upon completing development or testing, it’s essential to delete clusters that are no longer needed. This helps free up system resources and maintain an uncluttered development environment. Moreover, deleting clusters avoids potential conflicts and ensures cleanliness across different development cycles.

Explanation:

• kind: The command to execute the ‘kind’ tool.
• delete clusters: Sub-command indicating the intent to delete one or more local clusters.
• cluster_name: The specific name of the cluster you wish to delete. This allows precise management of clusters, especially when several are deployed simultaneously.

Example Output:

Deleting cluster "cluster_name" ...
✓ Deleting node "kind-control-plane"  ...

Use case 3: Get details about clusters, nodes, or the kubeconfig

Code:

kind get clusters|nodes|kubeconfig

Motivation:

Retrieving information about clusters, nodes, or kubeconfig is vital for monitoring and managing Kubernetes environments effectively. Knowing which clusters are running, what nodes they contain, or having quick access to kubeconfig details helps in auditing and can streamline troubleshooting processes.

Explanation:

• kind: The command to execute the ‘kind’ tool.
• get: Sub-command used to retrieve information.
• clusters|nodes|kubeconfig: Specify what information you’re querying. This flexibility allows users to get an overview or inspect specific parts of their Kubernetes configurations.

Example Output for kind get clusters:

cluster_name_1
cluster_name_2

Example Output for kind get nodes:

kind-control-plane

Example Output for kind get kubeconfig:

apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: ...
    server: https://127.0.0.1:45127
  name: kind-cluster_name

Use case 4: Export the kubeconfig or the logs

Code:

kind export kubeconfig|logs

Motivation:

Exporting the kubeconfig or logs is essential for sharing configurations, analyzing cluster behavior, or retaining logs for historical data and audit trails. Exported configurations can be used in different environments or sharing with team members, while exporting logs can facilitate debugging and performance analysis.

Explanation:

• kind: The command to execute the ‘kind’ tool.
• export: Sub-command to initiate the export process.
• kubeconfig|logs: The specific data you wish to export. Choosing kubeconfig allows you to transfer or back up your configuration, whereas logs provide insights into operational aspects and help identify issues.

Example Output for kind export kubeconfig:

Upon running the command, the kubeconfig is exported and can be found in the default kubeconfig file location (~/.kube/config), seamlessly merging with existing configurations.

Example Output for kind export logs:

Exported logs to:
- /tmp/kind-cluster_name-logs20211028-115840

Each use case above demonstrates the capabilities of kind in creating and managing local Kubernetes clusters, making it a versatile tool for developers working with Kubernetes.