Inside Kubernetes Control Plane & Envoy Service Mesh
An evidence-audited, 20-diagram interactive system breakdown tracing API Server admission controllers, etcd watch multiplexing, Kube-Scheduler scoring loops, Controller Manager reconciliation, Envoy xDS dynamic configuration, and mTLS certificate renewal.
Executive Summary
Kubernetes and Envoy form the foundation of modern cloud-native infrastructure. This 20-diagram interactive system breakdown deconstructs the control plane and service mesh data plane execution flow.
1. API Server Admission Controllers & etcd Watch Multiplexing
Incoming resource modification requests pass through API Server Authentication, Authorization, Mutating Webhooks, and Validating Webhook admission controllers before committing to etcd storage.
2. Kube-Scheduler Scoring & Node Affinity Evaluation
The Kube-Scheduler evaluates pod resource specifications against node capacity, running Filter predicates and Priority Scoring loops to select optimal candidate nodes.
3. Controller Manager Reconciliation Loops
The Controller Manager executes continuous control loops comparing observed cluster state against desired YAML specs, issuing delta modification actions to achieve state convergence.
4. Envoy Sidecar Proxy Dynamic xDS Configuration
Envoy sidecars receive real-time dynamic configuration updates from the control plane using xDS APIs (Listener Discovery LDS, Route Discovery RDS, Cluster Discovery CDS, Endpoint Discovery EDS).