Retirement: Flatcar Container Linux for AKS (preview)

Azure Kubernetes Service support for Flatcar Container Linux for AKS (preview) will be retired on June 8, 2026, transition to a supported alternative by that date.

From now to June 7, 2026, you can continue to use Flatcar Container Linux for AKS (preview) without disruption. Starting on June 8, 2026, AKS will no longer support Flatcar Container Linux for AKS (preview). You will no longer be able to create new node pools. AKS will not produce new node images and will no longer provide security patches for existing node pools. AKS will remove Flatcar Container Linux for AKS (preview) node images and existing code on September 8, 2026, meaning that scaling and remediation operations will fail.

Required Action:

• Use Ubuntu if you're looking for a portable, general purpose OS with cross-cloud support.
• Use Azure Linux if you're looking for a general purpose OS that is Microsoft-created and optimized for Azure.

Learn more.