1. What is EKS Platform Version?

The EKS Platform Version represents the capabilities of the EKS control plane, such as:

• Kubernetes API server feature flags and configurations.
• Security patches and bug fixes provided by AWS.
• AWS-specific enhancements like IAM roles for service accounts (IRSA), KMS encryption, Fargate improvements, etc..
• Performance optimizations for the EKS control plane.

Each Kubernetes minor version (e.g., 1.27, 1.28) has its own set of EKS platform versions (eks.1, eks.2, etc.).

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2. How is EKS Platform Version Different from Kubernetes Version?

Aspect	EKS Platform Version	Kubernetes Version
Definition	AWS’s versioning for EKS control plane enhancements and patches	Kubernetes upstream version supported by AWS
Purpose	Controls AWS-managed EKS features, security patches, and performance improvements	Determines the Kubernetes API version, features, and workload compatibility
Scope	Only impacts the EKS control plane	Impacts both control plane and worker nodes
Updates	AWS releases new platform versions without changing Kubernetes versions	Must be explicitly upgraded by the user
Example	eks.1, eks.2, eks.3 (for Kubernetes 1.27)	Kubernetes 1.26, 1.27, 1.28

✅ Key takeaway:

• Kubernetes Version = Upstream Kubernetes API version (affects workloads & node compatibility).
• EKS Platform Version = AWS’s optimizations for Kubernetes control plane (does not affect workload compatibility).

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3. Can You Choose the EKS Platform Version When Deploying a Cluster?

❌ No, you CANNOT manually choose the EKS Platform Version.

• When you create an EKS cluster, AWS automatically assigns the latest platform version for that Kubernetes version.
• However, you can check the assigned platform version after deployment: aws eks describe-cluster --name my-cluster --query "cluster.platformVersion" --output text

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4. List of Available EKS Platform Versions

AWS does not provide a direct CLI command to list all platform versions. However, you can check available platform versions for each Kubernetes version in the official AWS documentation:

📌 Amazon EKS Platform Versions

Each Kubernetes minor version has its own platform versions (eks.1, eks.2, etc.), and platform versions are not shared across Kubernetes versions.

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5. Comparison of EKS Platform Versions

Each EKS Platform Version brings different enhancements. Here’s a comparison for Kubernetes 1.27 as an example:

EKS Platform Version	Features & Enhancements
eks.1	Initial release of Kubernetes 1.27 in EKS
eks.2	Security patches for the control plane
eks.3	IAM Role for Service Accounts (IRSA) improvements
eks.4	Enhanced Fargate compatibility & logging improvements

To get a detailed list of changes per platform version, visit:
📌 Amazon EKS Platform Versions

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6. How to Check Your EKS Platform Version

Run the following AWS CLI command:

aws eks describe-cluster --name my-cluster --query "cluster.platformVersion" --output text
Code language: JavaScript (javascript)

✅ Example output:

eks.3
Code language: CSS (css)

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7. How to Upgrade the EKS Platform Version?

AWS automatically upgrades platform versions when upgrading EKS Kubernetes versions.

To upgrade:

aws eks update-cluster-version --name my-cluster --kubernetes-version 1.28
Code language: CSS (css)

⚠️ Note: AWS does not support manually upgrading platform versions within the same Kubernetes version.

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8. Summary

Question	Answer
What is EKS Platform Version?	AWS’s versioning for EKS control plane capabilities, security patches, and optimizations.
How is it different from Kubernetes Version?	Kubernetes Version affects workloads and API compatibility, while EKS Platform Version affects AWS-managed control plane settings.
Can you choose a specific platform version?	❌ No, AWS assigns the latest platform version automatically.
Where to find available platform versions?	📌 AWS EKS Documentation
How to check your platform version?	Run aws eks describe-cluster --name my-cluster --query "cluster.platformVersion"
How to upgrade platform versions?	Upgrade the EKS Kubernetes version, AWS automatically applies the latest platform version.

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What is Bundled in an EKS Platform Version?

Each EKS Platform Version is a bundle of AWS-managed control plane enhancements, including:

1. Kubernetes Control Plane Configuration
2. Security Patches & Fixes
3. AWS-Specific Feature Enhancements
4. Performance & Stability Improvements
5. Networking & IAM Updates
6. Bug Fixes & Deprecations

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1️⃣ Kubernetes Control Plane Configuration

• Determines which Kubernetes API server flags are enabled.
• Introduces new features supported by AWS for that Kubernetes version.
• Enables default settings for control plane components (e.g., API server, controller manager, etc.).

Example:

• eks.1 might enable an experimental feature like alpha.kubernetes.io/instance-type but disable it in eks.2 if found unstable.

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2️⃣ Security Patches & Fixes

• AWS applies critical security patches for Kubernetes vulnerabilities.
• Addresses CVE (Common Vulnerabilities and Exposures) affecting the control plane.
• Ensures IAM Role for Service Accounts (IRSA) and OIDC provider security updates.

Example:

• A Kubernetes API server vulnerability might be patched in EKS 1.27 eks.3, but not in eks.1.

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3️⃣ AWS-Specific Feature Enhancements

• New AWS service integrations such as:
  • AWS Fargate improvements for serverless Kubernetes.
  • Enhanced Amazon VPC CNI (Container Networking Interface).
  • KMS Encryption improvements for Kubernetes secrets.
  • Better IAM Role for Service Accounts (IRSA) handling.
• Enables default add-ons like kube-proxy, CoreDNS, and Amazon VPC CNI.

Example:

• eks.3 might introduce multi-architecture support for ARM64 nodes, improving cost optimization for workloads.

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4️⃣ Performance & Stability Improvements

• Enhancements in API Server request handling and controller performance.
• Improvements in control plane auto-scaling & resource utilization.
• Reduces latency in Kubernetes API calls.

Example:

• eks.2 might introduce faster node registration compared to eks.1.

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5️⃣ Networking & IAM Updates

• Improves VPC CNI plugin for better networking performance.
• Updates IAM permissions for managed node groups.
• Enhances load balancer and ALB integration.

Example:

• eks.4 might optimize VPC networking for IPv6 support.

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6️⃣ Bug Fixes & Deprecations

• Fixes bugs in previous EKS platform versions.
• Deprecates unsupported Kubernetes APIs.
• Ensures backward compatibility with older platform versions.

Example:

• eks.5 might remove an old PodSecurityPolicy (PSP) API deprecated in Kubernetes 1.25.

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Key Takeaways

✔ EKS Platform Version bundles AWS-specific enhancements for security, networking, and performance.
✔ Newer platform versions contain fixes, security patches, and feature upgrades for your control plane.
✔ You CANNOT manually select a platform version—AWS assigns the latest one for your Kubernetes version.
✔ Upgrading the Kubernetes version automatically moves you to the latest platform version.

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