Kustomize vs k3s: What are the differences?

Introduction Kustomize and k3s are two popular tools utilized in the realm of Kubernetes. While both tools have similarities, there are significant differences that set them apart. In this markdown code, we will explore and highlight six key differences between Kustomize and k3s.

1. Deployment Approach: Kustomize primarily focuses on the management and customization of Kubernetes resource configurations. It allows users to modify and manage YAML files for efficient deployment and update of applications. On the other hand, k3s is a lightweight Kubernetes distribution that simplifies the deployment and management of Kubernetes clusters, incorporating numerous components required for running Kubernetes.

2. Resource Management: Kustomize works by leveraging base and overlay configurations. The base configuration defines the common resources that are shared among different deployments, while the overlay configuration specifies the modifications made for specific environments or use cases. In contrast, k3s provides a simplified way of managing resources by abstracting away the complexity of dealing with individual YAML files, allowing users to interact with Kubernetes resources more directly.

3. Installation Requirements: Kustomize is a standalone tool that can be used with any Kubernetes installation, including k3s. It requires minimal setup and can be integrated into existing workflows seamlessly. Conversely, k3s is a complete Kubernetes distribution that can be installed and utilized directly without the need for additional Kubernetes components. This lightweight nature of k3s makes it particularly suitable for constrained and resource-constrained environments.

4. Footprint and Performance: Kustomize operates at the resource configuration level and does not impact the runtime performance of Kubernetes clusters. It allows for efficient management of resources without introducing any additional overhead. In contrast, k3s is designed to be a significantly lightweight Kubernetes distribution, utilizing fewer resources and having a smaller footprint compared to the standard Kubernetes setup. This lightweight nature translates to improved performance and faster boot times.

5. Cluster Provisioning: While Kustomize mainly focuses on resource configuration and management, it does not offer built-in cluster provisioning capabilities. Users need to have a pre-existing Kubernetes cluster in order to utilize Kustomize effectively. On the other hand, k3s simplifies the cluster provisioning process by automatically setting up a fully functional Kubernetes cluster with minimal effort. This feature makes k3s an ideal solution for developers and users looking for a quick and hassle-free way to set up Kubernetes environments.

6. Community and Adoption: Kustomize is an official subproject of the Kubernetes ecosystem, supported and maintained by the Kubernetes community. It has gained significant traction and is widely adopted among Kubernetes users. Conversely, k3s, although a popular tool, is not an official Kubernetes project. It is developed and maintained by Rancher Labs, an independent organization specializing in container management platforms.

In summary, Kustomize focuses on resource customization and management at the configuration level and requires an existing Kubernetes cluster, while k3s simplifies the deployment and management of Kubernetes clusters, providing a lightweight and resource-efficient solution with built-in cluster provisioning capabilities.