Kubernetes and AWS Networking Debugging

Datadog has developed a robust system for managing multiple AWS accounts securely and efficiently. This system leverages IAM users, groups, and roles to enforce granular access control, requiring MFA for privileged operations and grouping permissions by topic. The approach aims to balance security with usability, allowing for effective management of infrastructure across numerous accounts. This post details a deep dive into debugging a complex incident involving gRPC, Kubernetes, and AWS networking. It highlights how issues that initially appear to be DNS-related can stem from deeper networking problems, including connection tracking, reverse path filtering, and the interaction between different networking layers (Cilium, Kubernetes, AWS). The post emphasizes the importance of comprehensive visibility through tools like ENA metrics and VPC Flow Logs for diagnosing such issues.