Kubernetes and EKS Upgrade Strategy: Best Practices with Kapstan

Upgrading your Kubernetes clusters is a critical part of maintaining a secure, performant, and future-proof cloud-native infrastructure. Whether you’re self-managing Kubernetes or relying on managed services like Amazon EKS (Elastic Kubernetes Service), upgrades are not optional—they're necessary. At Kapstan, we help teams navigate Kubernetes and EKS upgrade challenges with a streamlined, automation-driven approach that minimizes downtime and mitigates risk.

In this blog, we’ll explore why upgrades matter, common pitfalls to avoid, and how Kapstan supports clients in adopting a reliable and scalable upgrade strategy.

Why You Should Upgrade Kubernetes (and EKS)

Kubernetes releases a new minor version roughly every 3–4 months. Each version brings performance enhancements, bug fixes, API deprecations, and security updates. Skipping versions can result in:

• Security vulnerabilities: Outdated clusters often miss critical patches.

• API incompatibilities: Deprecated APIs may break your workloads.

• Loss of support: Kubernetes only supports the last three minor versions.

• Blocked EKS upgrades: EKS relies on upstream Kubernetes support cycles.

By keeping up with Kubernetes upgrades, you ensure your infrastructure remains secure, compatible, and optimized for performance.

EKS Upgrade Challenges

Amazon EKS simplifies cluster management, but upgrades still involve complexity. Key challenges include:

• Node group version mismatches: Upgrading the control plane does not auto-upgrade worker nodes.

• Version skew risks: Ensuring that kubelets, kubectl, and the control plane remain compatible during the transition.

• Application disruptions: Downtime or performance degradation can occur if workloads aren't properly drained or tested.

Kapstan helps organizations orchestrate seamless EKS upgrades through automation and validation pipelines tailored to your workload and release cycles.

Kapstan’s Approach to Kubernetes and EKS Upgrades

At Kapstan, we treat upgrades as a lifecycle process, not a one-time event. Here's how we do it:

1. Inventory and Assessment

We begin by auditing your current Kubernetes cluster:

• Version check across control plane, node groups, and kubectl.

• Detect deprecated APIs via tools like pluto or kubent.

• Review cluster autoscaler, CNI plugins, and custom controllers for compatibility.

2. Upgrade Plan Design

We develop a detailed upgrade path:

• Define source and target versions.

• Select supported intermediate hops if required.

• Identify components (e.g., CoreDNS, kube-proxy, Calico) that need upgrading.

3. Pre-Upgrade Validation

Before touching production, we simulate the upgrade:

• Mirror your environment using Kapstan-managed staging clusters.

• Run conformance tests and chaos testing.

• Validate CI/CD pipelines and Helm chart compatibility.

4. Zero-Downtime Execution

During the upgrade:

• Control plane upgrade is triggered via EKS Console or CLI.

• Node groups are drained, upgraded, and rolled out using blue-green or canary strategies.

• Logs, metrics, and health checks are continuously monitored.

5. Post-Upgrade Checks

• Validate workloads and service endpoints.

• Rollback strategies are prepared in case of regressions.

• Update documentation and kubeconfig files.

With Kapstan, even complex EKS upgrades can be executed confidently and predictably.

Tools We Use

Kapstan leverages open-source and cloud-native tools to ensure a robust upgrade process:

• eksctl for cluster and node group upgrades.

• Kustomize/Helm for workload configuration management.

• Pluto/kubent for deprecated API scanning.

• Kyverno or OPA Gatekeeper for policy enforcement pre/post-upgrade.

• ArgoCD for GitOps-based rollout control.

Best Practices for Kubernetes & EKS Upgrades

Here are a few principles we follow and recommend:

• Don’t skip versions: Move one minor version at a time to reduce surprises.

• Upgrade dev/staging first: Always test your workloads in non-prod environments.

• Automate where possible: Use Infrastructure as Code and GitOps to minimize human error.

• Use managed node groups: They simplify lifecycle management compared to self-managed instances.

• Monitor everything: Set up detailed observability to catch regressions early.

Future-Proof Your Infrastructure with Kapstan

As Kubernetes evolves rapidly, keeping pace requires more than just running a few commands. You need a partner who understands the intricacies of cluster lifecycle management—especially in a cloud-native, EKS-powered world.

Kapstan offers Kubernetes consulting, platform engineering, and DevOps automation that helps teams design upgrade-safe systems from day one. Whether you're on EKS or any other managed Kubernetes service, we can take ownership of your upgrade pipeline and help you scale with confidence.