Introduction
Moving Kubernetes workloads off self-managed clusters, virtual machines, or bare-metal infrastructure is rarely a clean lift. Teams worry about breaking applications, losing data, loosening security controls, or stalling delivery pipelines mid-migration.
Amazon EKS takes the Kubernetes control plane off your plate. But that's only part of the job. CNCF's 2025 survey found cultural change (47%), training gaps (36%), and security (36%) remain top container challenges for organisations.
Those findings show migration success depends on people and process, not just infrastructure.
Migrating to EKS is an architecture and operations exercise, not a simple relocation. This guide compares Kubernetes and EKS responsibilities, walks through readiness assessment, outlines a phased migration process, and covers what to validate after cutover.
Key Takeaways
- EKS removes control-plane management effort but leaves worker capacity, networking, IAM, and data with your team
- Discovery and compatibility testing must happen before any production workload moves
- Stateless services migrate far more easily than stateful apps with persistent storage or strict latency needs
- A documented rollback plan, observability, and security controls are non-negotiable before cutover
- Cost governance should start on day one, not after the first unexpected AWS bill
What Changes When Kubernetes Moves to EKS?
Amazon EKS manages the Kubernetes control plane: AWS runs at least two API server instances and three etcd instances spread across three Availability Zones, and it handles their patching, scaling, and replacement. That's where AWS's job ends.
Everything else (worker nodes, add-ons, application configuration, networking, and data protection) stays with your organisation. The exact split, though, depends on which compute option you choose.
Responsibility Shifts by Compute Choice
| Compute option | What AWS handles | What you still manage |
|---|---|---|
| Managed node groups | Builds patched, EKS-optimised AMIs | Deploying patches; node scaling decisions |
| Self-managed EC2 nodes | Nothing beyond the control plane | Full node lifecycle and maintenance |
| EKS Fargate | No instance management at all | No DaemonSets or EBS volumes supported |
| EKS Auto Mode | Compute, networking, load balancing, storage | Workload-level configuration only |
Core AWS Components You'll Touch
A typical EKS architecture pulls together several AWS services your team didn't need to think about on bare metal or self-managed clusters:
- VPC and subnets spanning multiple Availability Zones
- Managed or self-managed node groups (or Fargate profiles)
- AWS Load Balancer Controller connecting Ingress to ALBs/NLBs
- Elastic Container Registry for image storage
- IAM roles for service accounts or EKS Pod Identity for workload permissions
- EBS and EFS CSI drivers for persistent volumes
- CloudWatch for control-plane logs and Container Insights for metrics
Your existing manifests, Helm charts, operators, admission policies, ingress rules, and storage classes all need a compatibility pass. A storage class tied to a specific on-premises driver, for instance, won't resolve on EKS without rework.
EKS isn't an automatic modernisation win. Simple, stateless services can often keep their existing deployment pattern with minor tweaks. Workloads that depend on cloud-provider-specific scaling, resilience, or observability features, however, usually need redesigning to take advantage of what AWS actually offers.
How to Plan a Kubernetes-to-EKS Migration
Planning starts with an honest inventory, not a migration date on a calendar.
Build Your Discovery Inventory
Document everything before you touch production:
- Clusters, namespaces, and workloads currently running
- Container images and Kubernetes versions in use
- Operators, custom controllers, and admission webhooks
- Service dependencies, ingress routes, and external integrations
- Secrets, ConfigMaps, and persistent volumes
- Databases, batch jobs, and scheduled tasks
Classify Workloads Before You Move Them
Not every service carries the same migration risk. Score each workload against:
- Criticality to the business
- Statefulness and data volume
- Compliance or regulatory obligations
- Traffic variability and latency sensitivity
- Recovery time and recovery point objectives
- Overall migration complexity
Check Compatibility Early
Review deprecated Kubernetes APIs, environment-specific features, custom controllers, storage drivers, and networking assumptions baked into your current setup. A cluster running older manifests might reference APIs that no longer exist in newer Kubernetes versions. Fix those references before migration, not after.
Then plan the AWS foundation: account structure, Region and AZ strategy, VPC design, IAM roles for workloads, node architecture, and connectivity back to anything staying outside AWS.
Define success criteria upfront before you run a single pilot:
- Correctness, latency, and throughput
- Availability and security posture
- Acceptable AWS spend
Start with a low-risk but representative workload, then move progressively to more critical services. Build a checklist your team must clear before any production cutover gets approved.
A Step-by-Step Kubernetes-to-EKS Migration Process
Once planning is done, the actual migration follows a fairly consistent sequence.
Build and secure the EKS landing zone. Stand up the AWS account structure, VPC, subnets, routing, IAM, logging, encryption, and node capacity. Choose managed node groups, self-managed nodes, or Fargate by workload profile (Fargate will not work with DaemonSets or EBS-backed volumes). Validate the design against current AWS and EKS documentation, since add-ons and Kubernetes versions change often.
Prepare application artefacts. Update container images, scan them for vulnerabilities, push approved versions to your registry, and validate Helm charts or manifests. Strip out any hard-coded infrastructure assumptions from the old environment.
Recreate platform dependencies. Configure namespaces, service accounts, IAM permissions, secrets, ConfigMaps, storage classes, ingress, certificates, autoscaling policies, and observability agents inside the new cluster.
Migrate data carefully. Choose replication, backup-and-restore, export/import, or application-level synchronisation based on your database and storage. Define downtime, consistency, retention, and rollback conditions in writing. Run a documented backup and restore test before any production traffic shift; this step gets skipped far too often, and it is the one that saves you during an incident.
Validate and cut over. Run functional, integration, security, performance, and failover tests. Shift traffic gradually using weighted DNS routing or a staged release rather than an all-at-once switch. Monitor key signals throughout.
Decommission responsibly. Keep required backups and audit records, remove unused infrastructure and credentials, update your diagrams and runbooks, and only retire the legacy cluster once the agreed rollback window has passed.
This mirrors how Cygnet One structures its own Secure Migration phase for enterprise clients, combining automated rehosting with parallel rollout and rollback plans governed from day zero rather than bolted on afterwards.
Secure and Operate Workloads After Migration
Cutover isn't the finish line. EKS runs on a shared-responsibility model, and most of the operational burden lands on you.
Security and Identity
- Enforce least-privilege IAM and use EKS Pod Identity or IRSA for workload access to AWS services
- Apply Kubernetes RBAC with minimal RoleBindings; avoid wildcard permissions
- Use network policies for pod-to-pod traffic control (not enabled by default on EKS)
- Favour private API endpoints, encrypt data at rest and in transit, and manage secrets through a dedicated service
- Scan or sign images before they reach the cluster, and keep a regular node-patching cadence
Observability and Reliability
Build a baseline using control-plane logs, application logs, metrics, traces, and audit events. Then set alerts and dashboards against clear service-level indicators.
When something breaks, you need to quickly tell whether it's an application bug, a node failure, a Kubernetes scheduling issue, or an AWS-side event.
For reliability, lean on multi-AZ placement, pod disruption budgets, readiness and liveness probes, autoscaling, and periodic disaster-recovery drills. Test your upgrade path on non-production clusters before touching anything live.
Day-Two Operations and Cost Governance
Ongoing work includes Kubernetes version upgrades, node replacement, add-on lifecycle management (EKS doesn't auto-update add-ons after a cluster upgrade), incident response, access reviews, and drift detection.
Cost control deserves equal attention. AWS's EKS pricing page lists standard support at $0.10 per cluster-hour, rising to $0.60 per cluster-hour once a Kubernetes version enters extended support, a detail that's easy to miss until the invoice arrives. Pair this awareness with:
- Realistic resource requests and limits
- Regular rightsizing and autoscaling reviews
- Idle-resource detection and consistent tagging
- Account-level budgets and workload ownership
Cygnet One's AWS cloud engineering practice builds this governance in from the start: CloudWatch dashboards, FinOps-based resource monitoring, and SOC 2-aligned operations sit alongside the migration work itself. If your team is weighing a broader cloud or digital transformation effort alongside the EKS move, that's a conversation worth having with Cygnet One directly.
Choose the Right Migration Approach and Avoid Common Pitfalls
There's no single correct way to move to EKS. The right approach depends on how much risk, time, and technical debt you're willing to carry.
| Approach | Speed | Risk | Long-term fit |
|---|---|---|---|
| Rehost (lift-and-shift) | Fastest | Lower initial risk, carries technical debt forward | Good for time-pressured moves |
| Rebuild cluster, redeploy apps | Moderate | Medium: new foundation, same app logic | Cleaner long-term operations |
| Modernise during migration | Slowest | Higher upfront effort | Best long-term scalability and cost efficiency |
Common Failure Points
- Treating EKS as fully managed Kubernetes and skipping worker-node planning
- Skipping dependency discovery before migration begins
- Moving storage without a tested recovery process
- Underestimating IAM and networking differences between environments
- Decommissioning the source environment before the rollback window closes
Crossuite, an AWS customer running manually managed on-premises Kubernetes, lifted its workloads to EKS using Terraform and GitLab CI/CD. Crossuite's case study reports 30% lower overall costs and 99.9% uptime after the move — a useful data point, though every environment's starting conditions differ.
Pick your migration pattern (phased, blue-green, parallel-cluster, or workload-by-workload) based on application criticality, data complexity, and how much rollback flexibility you need.
After go-live, run a short post-migration review covering actual performance, AWS spend, incident patterns, developer experience, and security findings. That review usually surfaces the next round of modernisation opportunities too.
Frequently Asked Questions
What are the key differences between hybrid cloud and public cloud?
Hybrid cloud combines private or on-premises infrastructure with public-cloud services, while public cloud runs workloads entirely on a provider's shared infrastructure. For Kubernetes workloads, this distinction determines whether EKS runs alongside your existing clusters or replaces them entirely.
What is Amazon EKS, and how is it different from self-managed Kubernetes?
EKS manages the Kubernetes control plane (API servers, etcd, and their availability) on your behalf. Your organisation still manages workload configuration, worker capacity, networking, IAM, data, and day-to-day operations.
Can every Kubernetes application be migrated to EKS?
Most standard workloads can be adapted, but compatibility checks are essential for storage drivers, networking assumptions, custom operators, cloud-provider integrations, deprecated APIs, and compliance constraints. Some applications need redesign work before they're ready.
How should persistent data be migrated from Kubernetes to EKS?
Options include backup-and-restore, replication, or application-level synchronisation, chosen based on your database and storage technology. Always test consistency and recovery before changing production traffic, and plan for acceptable downtime upfront.
How long does a Kubernetes-to-EKS migration take?
Timing depends on workload count and complexity, data volume, integrations, compliance requirements, and your chosen migration strategy. It's best to estimate duration after discovery rather than committing to a fixed timeline beforehand.
Who is responsible for security after moving Kubernetes to EKS?
AWS secures the control plane; your organisation owns IAM, Kubernetes RBAC, workload security, image management, network controls, secrets management, patching, monitoring, and compliance evidence under the shared-responsibility model.
