EnvoyFilter

An EnvoyFilter is a configuration tool used in Istio, a service mesh platform, that allows you to customize how network traffic is handled within a distributed application. It enables precise modifications to Envoy proxy behaviors—such as altering request or response data, adding headers, or changing routing logic—by inserting custom code at specific points. This flexibility helps developers tailor traffic management, security, or observability features without disrupting the overall system, ensuring better control and integration in complex microservice environments.