Envoy
Envoy is an open-source, high-performance Layer 7 proxy designed for cloud-native applications, providing service discovery, load balancing, observability, and resilience features at the network edge and between services.
Definition
Envoy is an open-source, high-performance Layer 7 proxy designed for cloud-native applications, providing service discovery, load balancing, observability, and resilience features at the network edge and between services.
Overview
Envoy was originally built at Lyft to manage communication between microservices, and was later donated to the Cloud Native Computing Foundation (CNCF), where it became a graduated project now widely adopted as foundational infrastructure across the cloud-native ecosystem. Written in C++ for performance, Envoy typically runs as a sidecar proxy alongside application containers, or as an edge and API gateway, handling traffic routing, retries, circuit breaking, TLS termination, and detailed telemetry — metrics, logs, and distributed traces — without requiring changes to application code. Envoy is the data-plane proxy underlying service meshes like Istio, and it integrates with observability tooling such as OpenTelemetry. It's commonly deployed in Kubernetes environments alongside gRPC-based microservices, either as an API gateway or as a sidecar handling traffic for individual services, and is frequently discussed alongside service-discovery tools like Consul.
Key Features
- High-performance C++ proxy built for cloud-native traffic patterns
- Sidecar deployment model alongside application containers
- Advanced load balancing, retries, timeouts, and circuit breaking
- Rich observability — metrics, structured logs, and distributed tracing out of the box
- Dynamic service discovery and configuration via APIs
- TLS termination and mutual TLS (mTLS) support
- Data-plane foundation for service meshes like Istio
- CNCF graduated project with broad cloud-native ecosystem adoption