// ECHO_IMAGE is the image to use when deploying echo services.
	// nolint: golint, revive, stylecheck
	ECHO_IMAGE Variable = "ECHO_IMAGE"

	// GRPC_ECHO_IMAGE is the image to use for a separate gRPC-only container in echo Pods.
	// nolint: golint, revive, stylecheck
	GRPC_ECHO_IMAGE Variable = "GRPC_ECHO_IMAGE"

	// KUBECONFIG is the list of Kubernetes configuration files. If configuration files are specified on
	// the command-line, that takes precedence.

		s.Image.PullPolicy = env.PULL_POLICY.ValueOrDefault("Always")
	}

	if s.EchoImage == "" {
		s.EchoImage = env.ECHO_IMAGE.ValueOrDefault("")
	}

	if s.CustomGRPCEchoImage == "" {
		s.CustomGRPCEchoImage = env.GRPC_ECHO_IMAGE.ValueOrDefault("")
	}

	if s.HelmRepo == "" {
		s.HelmRepo = "https://istio-release.storage.googleapis.com/charts"
	}

	if err = validate(s); err != nil {
		return nil, err
	}

	return s, nil
}