With k8s correctly handle disabled auto-scale up case (#495)

server/k8s.go

@@ -277,17 +277,14 @@ func (w *K8sWatcher) buildDetails(service *core.Service, externalServiceName str
 	rs := &routableService{
 		externalServiceName: externalServiceName,
 		containerEndpoint:   endpoint,
-		autoScaleUp: func(ctx context.Context) (string, error) {
-			if err := wakerFunc(ctx); err != nil {
-				return "", err
-			}
-			return endpoint, nil
-		},
+		autoScaleUp:         buildWakerFromSleeper(endpoint, wakerFunc),
 		autoScaleDown:       w.buildScaleFunction(service, 1, 0),
 	}
 	return rs
 }
 
+// buildScaleFunction generates a SleeperFunc to scale StatefulSets based on specified criteria and service annotations.
+// Will return nil if the service should not be auto-scaled due config or annotation.
 func (w *K8sWatcher) buildScaleFunction(service *core.Service, from int32, to int32) SleeperFunc {
 	// Currently, annotations can only be used to opt-out of auto-scaling.
 	// However, this logic is prepared also for opt-in, as it returns a `SleeperFunc` when flags are false but annotations are set to `enabled`.

server/routes.go

@@ -15,6 +15,18 @@ type WakerFunc func(ctx context.Context) (string, error)
 // SleeperFunc is a function that puts a server to sleep.
 type SleeperFunc func(ctx context.Context) error
 
+func buildWakerFromSleeper(endpoint string, sleeper SleeperFunc) WakerFunc {
+	if sleeper == nil {
+		return nil
+	}
+	return func(ctx context.Context) (string, error) {
+		if err := sleeper(ctx); err != nil {
+			return "", err
+		}
+		return endpoint, nil
+	}
+}
+
 var tcpShieldPattern = regexp.MustCompile("///.*")
 
 // RouteFinder implementations find new routes in the system that can be tracked by a RoutesHandler