Amazon VPC CNI

​

Coverage Matrix

​

Amazon VPC CNI Overview

Amazon VPC CNI (Amazon VPC Container Network Interface plugin) is the default networking plugin for AWS Kubernetes clusters (EKS). It runs on every node and creates Elastic Network Interfaces (ENIs) to assign VPC IP addresses to pods. This direct integration with AWS networking provides high-performance, low-latency pod connectivity on EKS. However, managing and upgrading the VPC CNI can be challenging - misconfigurations or unplanned changes could lead to IP exhaustion or network outages.

​

Chkk Coverage

​

Curated Release Notes

Chkk tracks official VPC CNI release notes and flags updates that matter, such as IP allocation changes or new prerequisites. Instead of combing through upstream change logs, operators see the changes that matter most for running clusters. By focusing on operational impact, these curated notes help you quickly identify shifts in IP management behavior, required configuration updates, or potential upgrade pitfalls.

​

Preflight & Postflight Checks

Upgrading the VPC CNI without proper checks can result in pod networking failures or downtime. Chkk runs preflight checks to ensure your environment meets all requirements before an upgrade. It verifies Kubernetes version compatibility and checks for known prerequisites - for instance, AWS notes that to upgrade to VPC CNI v1.12.0+ you must first be on v1.7.0, so Chkk will warn you if an intermediate upgrade is needed. After the upgrade, postflight checks confirm everything is healthy: Chkk verifies that all nodes are running the new CNI version, pods are receiving IPs normally, and there are no abnormal CNI pod logs or performance regressions.

​

Version Recommendations

Chkk continuously monitors Amazon VPC CNI’s release cycle and support timeline to keep you on a stable, supported version. It tracks which plugin releases are recommended for each Kubernetes version and flags any end-of-life (EOL) or out-of-support versions running in your clusters. You’ll get guidance on safe upgrade targets, ensuring you stay ahead of deprecations and security fixes before support lapses.

​

Upgrade Templates

Chkk provides Upgrade Templates for both in-place updates and blue-green rollout strategies. For an in-place upgrade, Chkk walks you through updating the CNI DaemonSet or EKS add-on step by step while maintaining network availability. For a more blue-green approach, Chkk can assist in setting up a parallel environment to test the new CNI version: for instance, bringing up a new set of nodes (or a staging cluster) with the updated CNI, moving a portion of workloads for validation, and then migrating traffic fully. Each template includes safety checkpoints and rollback instructions, so you can confidently promote the new CNI once it’s verified, or quickly revert if needed.

​

Preverification

By simulating the entire upgrade in an isolated “digital twin,” Chkk detects conflicts—like IP exhaustion or IAM permission gaps—before they hit production. For example, if the new version changes how IP addresses are allocated or introduces stricter requirements for custom networking (ENIConfig) or security group per pod features, those incompatibilities or errors will surface in the simulation. Any anomalies like IP assignment failures, excessive latency, or configuration warnings are flagged early. This means you only proceed with the real upgrade once it’s been proven safe in a replica of your environment.

​

Supported Packages

Whether you install the Amazon VPC CNI via Helm, Kustomize, or raw manifest, Chkk automatically detects your installation method and adapts its plan accordingly. Regardless of your packaging method (self-managed or EKS-managed add-on), Chkk’s checks and recommendations adapt accordingly. It also supports custom images or private registries - ensuring that even if you’re using a forked CNI build or an air-gapped registry, the upgrade workflow and validation checks still function seamlessly for your setup.

​

Common Operational Considerations

• IP Allocation Challenges: Each node has a finite pool of IPs based on how many ENIs it can attach, so running out of available addresses will halt pod scheduling. Adjusting instance sizes, using warm IP targets, or enabling prefix delegation helps avoid IP exhaustion.
• Scaling Considerations: As clusters grow, VPC-level IP space can become a bottleneck if subnets run out of capacity. Monitoring IP usage at scale and tuning the warm IP pool protect against AWS API throttling and networking delays.
• Security Best Practices: Ensure your nodes have the correct IAM roles (e.g., AmazonEKS_CNI_Policy) and consider using NetworkPolicies to enforce zero-trust. Regularly update the CNI for security patches and keep security groups aligned with least-privilege principles.
• Compatibility Issues: VPC CNI is tightly integrated with EKS, so chaining other CNIs or supporting Windows nodes requires matching versions.
• Monitoring & Troubleshooting: Pod IP assignment errors often surface in the aws-node logs or as failed scheduling events. Collecting Prometheus metrics and leveraging CloudWatch alarms allow quick detection of IP exhaustion or ENI attachment failures.

​

Additional Resources

• Amazon VPC CNI Documentation
• Amazon VPC CNI Releases