Kubernetes has matured significantly over the last decade, evolving from a niche project into the standard for modern infrastructure. While the CNCF ecosystem addresses many gaps, specific scenarios require tailored solutions. This article focuses on a critical intersection: deploying lightweight Kubernetes with K3s on on-premise hardware, specifically Proxmox, while utilizing k0rdent for declarative multi-cluster management. If you have struggled with manual VM creation or Bash scripts that become obsolete, this approach offers a declarative, repeatable, and clean alternative. We will walk through curating a use case for provisioning by writing custom Helm charts and utilizing k0rdent's Bring Your Own Template (BYOT) approach.
Addressing the Pain of Manual Provisioning
Running Kubernetes on on-premise infrastructure often leads to operational friction. Traditional workflows rely on manual VM creation and Bash scripts that only the original author understands. Clusters may function initially but quickly become untouchable as dependencies drift or configurations harden. We sought a solution that was declarative and repeatable without sacrificing the flexibility required for an on-prem setup. The combination of k0rdent, Proxmox, and K3s provides the necessary foundation. Instead of building images every time, we leverage existing VM templates to streamline the process. This shift from imperative scripts to declarative definitions ensures that the infrastructure layer is consistent and auditable.
Architecting the Custom k0rdent Template
To achieve the desired state management, we curated a specific use case for provisioning. The core of this architecture involves writing our own Helm charts to define the K3s cluster requirements. We then integrated these charts into k0rdent using its Bring Your Own Template (BYOT) approach. This method allows us to bypass the need for theoretical posturing and instead implement exactly how our cluster gets created in production. The template acts as a blueprint, ensuring that every provisioned cluster adheres to the defined standards. This is particularly relevant for professionals preparing for Kubernetes certifications, as it demonstrates advanced understanding of GitOps workflows and infrastructure as code.
Managing the Full Cluster Lifecycle
The ultimate goal is to enable end-users to host their infrastructure layer on-premise while we handle the complexity of building and maintaining it. By using k0rdent, we manage the full cluster lifecycle, from initial provisioning to ongoing updates. The system handles the orchestration of the K3s control plane and worker nodes automatically. This reduces the cognitive load on the engineering team, allowing them to focus on application deployment rather than infrastructure maintenance. The declarative nature of the template ensures that the desired state is always reflected in the actual state of the infrastructure, minimizing drift and human error.
What This Means For You
Implementing a custom k0rdent template transforms how you approach on-premise Kubernetes deployments. You gain the ability to provision clusters rapidly using existing VM templates, eliminating the need for repetitive image building. The workflow becomes standardized, making it easier to onboard new team members or scale operations across multiple sites. For DevOps professionals and AI engineers, this pattern provides a robust foundation for managing hybrid environments. By adopting this GitOps-first methodology, you ensure that your infrastructure remains resilient and manageable, even as the underlying hardware or software requirements evolve.
