Kubernetes: The Complete Guide for IT Leaders and Architects

It pays off when:

• you're running multiple applications or microservices that scale and deploy independently;
• you want to roll out frequently and automatically;
• you don't want to be tied to a single cloud or hosting provider;
• your development teams want to roll out updates securely on their own using an internal platform;
• you want to consolidate your virtual machines and containers onto a single platform, for example, to move away from VMware.

It usually isn't worth it if:

• you have one or a few simple applications with a stable load;
• you don't have the capacity or budget for management, whether in-house or outsourced;
• A simpler container service will suffice, such as AWS App Runner, Azure Container Apps, or a similar service from a European provider.

A container shares the operating system kernel with other containers and contains only the application and whatever it needs. This makes containers lightweight, quick to start, and easy to scale. A virtual machine (VM) has its own operating system and kernel, which makes it heavier but also more isolated and suitable for software that requires a full operating system.

The third approach: VMs on Kubernetes. With KubeVirt, you can run virtual machines as regular objects on a Kubernetes cluster, alongside your containers. Commercial options include Red Hat OpenShift Virtualization and SUSE Virtualization (based on Harvester). Sidero Labs is adding its own hypervisor to Talos Linux, with general availability scheduled for December 2026. This allows you to manage VMs and containers using the same tools, policies, and GitOps processes, and enables you to phase out your legacy virtualization platform before every application fits into a container.

Rule of thumb: containerize what you’re actively developing, run what’s stable or what a vendor requires as a VM, and bring both onto a single platform if you want to simplify management. If you need containers with the isolation of a VM, consider sandboxed runtimes such as Kata Containers or gVisor.

The core of Kubernetes is the same everywhere: the well-known distributions are certified by the CNCF as compliant. The differences lie in the installation, default settings, management tools, the underlying operating system, support, and the license.

Managed Kubernetes in the public cloud

Enterprise platforms for on-premises and hybrid environments

Lightweight distributions for edge computing and small clusters

Immutable Operating Systems for Kubernetes

Talos Linux from Sidero Labs is an operating system designed solely to run Kubernetes. There is no SSH, no shell, and no package manager: you manage each node via an API secured with mutual TLS, using declarative configuration in line with GitOps. The system is minimal and read-only, with CIS-hardened default settings, SELinux, secure boot, and one-step upgrades for both the operating system and Kubernetes, which can be rolled back. Talos is open source (MPL-2.0). Omni is the accompanying management environment for cluster provisioning, upgrades, and backups, available as SaaS or self-hosted. In September 2026, Sidero Labs was acquired by Yardi Systems, which is allowing it to continue as an independent company.

Talos is a good fit for organizations that want to manage many identical clusters—whether on-premises or at the edge—and minimize their attack surface. It does, however, require a different way of working: troubleshooting is done via the API and tools, without logging in to the server. Similar immutable operating systems include Flatcar Container Linux and AWS Bottlerocket.

Kubernetes-as-a-Service Platforms

Self-installed (vanilla)

With kubeadm, you install upstream Kubernetes without any add-ons. This provides maximum flexibility and no licensing costs, but you have to set everything up yourself and bear the full burden of management. This is only practical for teams with extensive in-house platform expertise.

• Access via central identities (SSO), with roles based on the principle of least privilege (RBAC).
• Network policies: closed by default; allow traffic only when necessary.
• Scan images for vulnerabilities, sign them, and allow them only from trusted registries.
• Enforce policies using Kyverno or OPA Gatekeeper: no root containers, mandatory resource limits, Pod Security Standards.
• Store secrets in a secrets manager, not in code or configuration files.
• Audit logging is enabled and stored centrally.
• The control plane is not publicly accessible.
• A standardized process for upgrades and patches, including those for the nodes' operating systems.

NIS2 and the Cybersecurity Act. The Cybersecurity Act, which implements NIS2, has been in effect in the Netherlands since August 15, 2026. If your organization falls under its scope, you must, among other things, demonstrate that you patch vulnerabilities in a timely manner, control access, detect incidents, and assess your suppliers. For a Kubernetes platform, this means: a well-maintained upgrade process, image scanning, audit logging, and formal agreements with your management partner. Have your legal counsel or compliance officer review how these requirements apply to your organization.

Kubernetes releases a new version approximately every four months. Each version receives about 14 months of upstream support. So expect one to two upgrades per cluster per year, including testing of applications and add-ons. If you delay upgrades, you’ll end up making larger and riskier jumps later on, because you can only move up one version at a time.

Extended support provides some breathing room, but it doesn’t solve the problem: even then, you’ll eventually have to catch up on multiple versions at once. Therefore, automate upgrades as much as possible, test them first on a non-production cluster, and check in advance which APIs are being deprecated.

• Observability: centrally collecting metrics, logs, and traces—for example, using Prometheus, Grafana, and OpenTelemetry, or Elastic or Dynatrace. Without observability, troubleshooting in Kubernetes is a guessing game.
• GitOps: The entire configuration of clusters and applications is stored in Git, and a tool like Argo CD or Flux automatically brings the cluster into that state. Changes become traceable, repeatable, and reversible. With an API-driven OS like Talos, this also applies to the nodes themselves.

1. Infrastructure: nodes, storage, network, and load balancers, plus the control plane for managed services.
2. Licenses and support: for example, OpenShift, Rancher Prime, Talos Enterprise Linux, or extended support from a cloud provider.
3. Management: the engineers who build, upgrade, secure, and monitor the platform 24/7. Often the largest expense.

You can save money primarily by making realistic resource requests, using autoscaling, reducing the number of clusters, and allocating costs by team—for example, with OpenCost. Learn more in the guide on reducing cloud costs.

Cluster sprawl occurs when teams create clusters independently of one another: higher costs, different versions, inconsistent security, and a lack of visibility. Here’s what helps:

• a single platform team that delivers clusters as standard, based on fixed templates and GitOps;
• centralized management of multiple clusters, using Rancher, Omni, Kubermatic, or OpenShift Advanced Cluster Management;
• The rule of thumb is that a new cluster should only be created for a compelling reason (compliance, isolation, location). Otherwise, a namespace is sufficient.

When multiple teams are working on Kubernetes, an internal developer platform is worthwhile: a self-service layer that allows teams without in-depth Kubernetes knowledge to roll out deployments securely, using predefined templates, pipelines, and guardrails. The platform team treats that platform as an internal product, with the development teams as its customers. Learn more in the guide on platform engineering.

To manage production clusters in-house, you’ll need at least two to three experienced platform engineers—and more for 24/7 coverage. They must be proficient in Linux, networking, storage, security, and automation. Relevant certifications include CKA (administration), CKAD (development), and CKS (security). Many organizations manage their applications in-house and outsource the underlying platform. To learn how to make that decision, read the guide on outsourcing IT management.