2. Envoy

Why not use Envoy directly?

• Service Mesh is one of application of Envoy.
• Envoy Proxy is capable of being deployed into many different types of cluster.
• It has a massive and complex terminology of its own.
• Istio simplifies envoy and allow us to use regular K8s yaml (via CRDs) to implement Envoy.

Introduction

• Website - Envoy
• Istio uses an extended version of the Envoy proxy.
  • In Istio: Proxy = sidecar = Envoy
• Envoy is made by lyft.
• Envoy is a high-performance proxy developed in C++ to mediate all inbound and outbound traffic for all services in the service mesh.
• Envoy proxies are the only Istio components that interact with data plane traffic.
  • For example:
    • The metrics of tracing (Jeager, Kiali)
    • circut breaker
• Reverse Proxy in Envoy:
  • request -> Proxy -> target
  • The client knows they have called the proxy.
  • The client thinks the results have come from the proxy.

References

• Envoy