Discovery empty response bug fix (#2) (#65)

Author: andreacv98

pkg/rear-controller/gateway/client.go

@@ -180,7 +180,13 @@ func (g *Gateway) DiscoverFlavours(ctx context.Context, selector *nodecorev1alph
 			klog.Errorf("Error when searching Flavour: %s", err)
 			return nil, err
 		}
-		flavoursCR = append(flavoursCR, flavour)
+		// Check if the flavour is nil
+		if flavour == nil {
+			klog.Infof("No Flavours found for provider %s", provider)
+		} else {
+			klog.Infof("Flavour found for provider %s", provider)
+			flavoursCR = append(flavoursCR, flavour)
+		}
 	}
 
 	klog.Infof("Found %d flavours", len(flavoursCR))

pkg/rear-controller/gateway/provider.go

@@ -53,26 +53,30 @@ func (g *Gateway) getFlavours(w http.ResponseWriter, _ *http.Request) {
 
 	klog.Infof("Found %d Flavours in the cluster", len(flavours))
 
+	availableFlavours := make([]nodecorev1alpha1.Flavour, 0)
+
 	// Filtering only the available flavours
 	for i := range flavours {
 		if !flavours[i].Spec.OptionalFields.Availability {
-			flavours = append(flavours[:i], flavours[i+1:]...)
+			availableFlavours = append(availableFlavours, flavours[i])
 		}
 	}
 
-	klog.Infof("Available Flavours: %d", len(flavours))
-	if len(flavours) == 0 {
+	klog.Infof("Available Flavours: %d", len(availableFlavours))
+	if len(availableFlavours) == 0 {
 		klog.Infof("No available Flavours found")
-		http.Error(w, "No Flavours found", http.StatusNotFound)
+		// Return content for empty list
+		emptyList := make([]*nodecorev1alpha1.Flavour, 0)
+		encodeResponseStatusCode(w, emptyList, http.StatusNoContent)
 		return
 	}
 
 	// Select the flavour with the max CPU
 	max := resource.MustParse("0")
 	index := 0
-	for i := range flavours {
-		if flavours[i].Spec.Characteristics.Cpu.Cmp(max) == 1 {
-			max = flavours[i].Spec.Characteristics.Cpu
+	for i := range availableFlavours {
+		if availableFlavours[i].Spec.Characteristics.Cpu.Cmp(max) == 1 {
+			max = availableFlavours[i].Spec.Characteristics.Cpu
 			index = i
 		}
 	}
@@ -118,17 +122,21 @@ func (g *Gateway) getFlavoursBySelector(w http.ResponseWriter, r *http.Request)
 
 	klog.Infof("Found %d Flavours in the cluster", len(flavours))
 
+	availableFlavours := make([]nodecorev1alpha1.Flavour, 0)
+
 	// Filtering only the available flavours
 	for i := range flavours {
-		if !flavours[i].Spec.OptionalFields.Availability {
-			flavours = append(flavours[:i], flavours[i+1:]...)
+		if flavours[i].Spec.OptionalFields.Availability {
+			availableFlavours = append(availableFlavours, flavours[i])
 		}
 	}
 
-	klog.Infof("Available Flavours: %d", len(flavours))
-	if len(flavours) == 0 {
+	klog.Infof("Available Flavours: %d", len(availableFlavours))
+	if len(availableFlavours) == 0 {
 		klog.Infof("No available Flavours found")
-		http.Error(w, "No Flavours found", http.StatusNotFound)
+		// Return content for empty list
+		emptyList := make([]*nodecorev1alpha1.Flavour, 0)
+		encodeResponseStatusCode(w, emptyList, http.StatusNoContent)
 		return
 	}
 
@@ -140,7 +148,7 @@ func (g *Gateway) getFlavoursBySelector(w http.ResponseWriter, r *http.Request)
 	}
 
 	klog.Infof("Filtering Flavours by selector...")
-	flavoursSelected, err := common.FilterFlavoursBySelector(flavours, selector)
+	flavoursSelected, err := common.FilterFlavoursBySelector(availableFlavours, selector)
 	if err != nil {
 		http.Error(w, "Error getting the Flavours by selector", http.StatusInternalServerError)
 		return
@@ -150,7 +158,9 @@ func (g *Gateway) getFlavoursBySelector(w http.ResponseWriter, r *http.Request)
 
 	if len(flavoursSelected) == 0 {
 		klog.Infof("No matching Flavours found")
-		http.Error(w, "No Flavours found", http.StatusNotFound)
+		// Return content for empty list
+		emptyList := make([]*nodecorev1alpha1.Flavour, 0)
+		encodeResponse(w, emptyList)
 		return
 	}
 
@@ -159,8 +169,8 @@ func (g *Gateway) getFlavoursBySelector(w http.ResponseWriter, r *http.Request)
 	index := 0
 
 	for i := range flavoursSelected {
-		if flavours[i].Spec.Characteristics.Cpu.Cmp(max) == 1 {
-			max = flavours[i].Spec.Characteristics.Cpu
+		if flavoursSelected[i].Spec.Characteristics.Cpu.Cmp(max) == 1 {
+			max = flavoursSelected[i].Spec.Characteristics.Cpu
 			index = i
 		}
 	}

pkg/rear-controller/gateway/services.go

@@ -47,8 +47,13 @@ func searchFlavourWithSelector(ctx context.Context, selector *models.Selector, a
 
 	defer resp.Body.Close()
 
-	// Check if the response status code is 200 (OK)
-	if resp.StatusCode != http.StatusOK {
+	switch resp.StatusCode {
+	case http.StatusOK:
+		klog.Infof("Received OK response status code: %d", resp.StatusCode)
+	case http.StatusNoContent:
+		klog.Infof("Received No Content response status code: %d", resp.StatusCode)
+		return nil, nil
+	default:
 		return nil, fmt.Errorf("received non-OK response status code: %d", resp.StatusCode)
 	}
 
@@ -74,7 +79,12 @@ func searchFlavour(ctx context.Context, addr string) (*nodecorev1alpha1.Flavour,
 	defer resp.Body.Close()
 
 	// Check if the response status code is 200 (OK)
-	if resp.StatusCode != http.StatusOK {
+	switch resp.StatusCode {
+	case http.StatusOK:
+		break
+	case http.StatusNoContent:
+		return nil, nil
+	default:
 		return nil, fmt.Errorf("received non-OK response status code: %d", resp.StatusCode)
 	}
 

pkg/rear-controller/gateway/utils.go

@@ -69,12 +69,16 @@ func handleError(w http.ResponseWriter, err error, statusCode int) {
 
 // encodeResponse encodes the response as JSON and writes it to the response writer.
 func encodeResponse(w http.ResponseWriter, data interface{}) {
+	encodeResponseStatusCode(w, data, http.StatusOK)
+}
+
+func encodeResponseStatusCode(w http.ResponseWriter, data interface{}, statusCode int) {
 	resp, err := json.Marshal(data)
 	if err != nil {
 		handleError(w, err, http.StatusInternalServerError)
 	}
 
 	w.Header().Set("Content-Type", "application/json")
-	w.WriteHeader(http.StatusOK)
+	w.WriteHeader(statusCode)
 	_, _ = w.Write(resp)
 }