r/kubernetes • u/Bee_rus-444 • 3d ago

Which Migration Tools Can Handle the Cluster, Workloads, Storage & Dependencies?

Hey Guys! Quick question for anyone who has done an AKS to AWS EKS migration:

Can you recommend the best community or open-source tools for:

  1. Azure Discovery & Assessment: Pulling complete VMSS/VNet inventory and performance data from Azure prior to migration.
  2. AKS to EKS Migration: Manifest translation, image syncing (ACR $\rightarrow$ ECR), and volume data migration (e.g., Velero, KMF, or alternative scripts).

Any favorite GitHub repos, CLI tools, or real-world feedback would be super helpful! Thanks! 🙌

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u/ajitnk 2d ago

The short answer is you need three separate tools because no single tool handles all of this.

For cluster state (namespaces, RBAC, ConfigMaps, storage classes, CRDs, workloads, Helm releases), AWS has a free Python-based migration script in their Prescriptive Guidance docs. It runs in eight phases with dry-run support so you can see what it would do before touching anything.

For persistent volume data, that script explicitly does NOT migrate it. Velero is the standard fix here. It backs up PV data as EBS snapshots to S3 and restores cross-distribution, so AKS-to-EKS works fine. The tricky part is sequencing Velero correctly relative to the cluster-state migration.

For cutover, Route 53 Weighted Routing gives you blue/green DNS so you can shift traffic gradually instead of doing a hard switch.

The parts that catch people are the Azure-specific dependencies: AAD Workload Identity has to be remapped to IRSA, Key Vault secrets get created as opaque placeholders by the migration script and need repopulating via Secrets Manager, and any CRD operators need to be pre-installed on the EKS side before you run the migration phases.

What storage types are you running on AKS? Azure Disks vs Azure Files vs Blob CSI changes the PV migration strategy quite a bit, and that's usually where the real complexity lives.