How to Mock a Service Mesh Sidecar Proxy in Python

class SidecarProxy:
    def __init__(self, name):
        self.name = name
        self.routes = {}
        self.services = {}
        self.requests_processed = 0

    def register_service(self, service_name, address, port):
        self.services[service_name] = f"{address}:{port}"

    def add_route(self, path, service_name):
        self.routes[path] = service_name
        print(f"[{self.name}] Added route: {path} -> {service_name}")

    def handle_request(self, path, method="GET"):
        self.requests_processed += 1
        print(f"[{self.name}] Received {method} request for {path}")

        if path not in self.routes:
            print(f"[{self.name}] 404 Not Found")
            return None

        service = self.services[self.routes[path]]
        print(f"[{self.name}] Proxying to {service}")
        return service

    def get_stats(self):
        return {
            "proxy_name": self.name,
            "requests_processed": self.requests_processed,
            "routes_configured": len(self.routes),
            "services_registered": len(self.services)
        }


if __name__ == "__main__":
    proxy = SidecarProxy("envoy-mock")
    proxy.register_service("user-service", "10.0.0.1", 8080)
    proxy.register_service("order-service", "10.0.0.2", 8081)

    proxy.add_route("/api/users", "user-service")
    proxy.add_route("/api/orders", "order-service")

    proxy.handle_request("/api/users")
    proxy.handle_request("/api/orders", "POST")
    proxy.handle_request("/api/unknown")

    print(f"\nProxy stats: {proxy.get_stats()}")