Merge pull request #42 from chez-shanpu/no-best-path-no-change

When there is no best path, it sends nothing to control plane

cmd/appagent/app/run.go

@@ -48,11 +48,15 @@ var runCmd = &cobra.Command{
 				fmt.Printf("[ERROR] %v", err)
 				os.Exit(1)
 			}
-
-			err = appagent.SendSRInfoToControlPlane(list, tls, cpCertFilePath, cpAddr, appName, srcAddr, dstAddr)
-			if err != nil {
-				fmt.Printf("[ERROR] %v", err)
-				os.Exit(1)
+			//If there is the best path, it sends that path to control plane
+			if list != nil {
+				err = appagent.SendSRInfoToControlPlane(list, tls, cpCertFilePath, cpAddr, appName, srcAddr, dstAddr)
+				if err != nil {
+					fmt.Printf("[ERROR] %v", err)
+					os.Exit(1)
+				}
+			} else {
+				fmt.Println("[INFO] No list was sent.")
 			}
 			time.Sleep(time.Duration(interval) * time.Millisecond)
 		}

pkg/appagent/appagent.go

@@ -101,6 +101,11 @@ func MakeSIDList(graph *dijkstra.Graph, depSids []string, dstSid string) (*[]str
 	if err != nil {
 		return nil, fmt.Errorf("failed to searching shortest path: %v", err)
 	}
+	// if there is no best path, it returns nil
+	if best.Distance >= infCost {
+		fmt.Printf("[INFO] There is no best path. cost: %v \n", best.Distance)
+		return nil, nil
+	}
 
 	var sids []string
 	for _, verIndex := range best.Path {