What is defined in the Envoy configuration file?

The Envoy configuration file is crucial as it dictates the behavior of the proxy itself, including how traffic is routed, the various settings that control its operation, and how it interacts with other microservices. This encompasses defining clusters, listeners, routes, and any specific filters that may be applied to the traffic flowing through the proxy. By detailing these parameters, the configuration file enables Envoy to manage requests and responses efficiently, ensuring that network traffic is handled according to the specified rules and requirements of your infrastructure.

In contrast, while health checks for external services are important to ensure the reliability of those services, they are typically managed through configurations that may not necessarily be part of the primary Envoy configuration file. Additionally, user identity and authorization attributes are generally dealt with through separate identity management solutions, rather than directly in the proxy's configuration. Finally, logging patterns and metrics, while essential for monitoring and debugging, are typically configured in a different context and serve different purposes than defining the core routing and operational behaviors of the proxy.