From 7934759ac24479ac420d6f7148eb004ad411c66b Mon Sep 17 00:00:00 2001
From: Murali Reddy <murali.reddy@cloudnativelabs.net>
Date: Sat, 5 Aug 2017 03:32:16 +0530
Subject: [PATCH] Randomize service endpoint addition when configuring
 destination on ipvs service

Fixes #99
---
 app/controllers/network_services_controller.go | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/app/controllers/network_services_controller.go b/app/controllers/network_services_controller.go
index 8765f90e..e1d851a9 100644
--- a/app/controllers/network_services_controller.go
+++ b/app/controllers/network_services_controller.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"io/ioutil"
+	"math/rand"
 	"net"
 	"net/http"
 	"reflect"
@@ -422,6 +423,14 @@ func buildServicesInfo() serviceInfoMap {
 	return serviceMap
 }
 
+func shuffle(endPoints []endpointsInfo) []endpointsInfo {
+	for index1 := range endPoints {
+		index2 := rand.Intn(index1 + 1)
+		endPoints[index1], endPoints[index2] = endPoints[index2], endPoints[index1]
+	}
+	return endPoints
+}
+
 func buildEndpointsInfo() endpointsInfoMap {
 	endpointsMap := make(endpointsInfoMap)
 	for _, ep := range watchers.EndpointsWatcher.List() {
@@ -432,7 +441,7 @@ func buildEndpointsInfo() endpointsInfoMap {
 				for _, addr := range ep_subset.Addresses {
 					endpoints = append(endpoints, endpointsInfo{ip: addr.IP, port: int(port.Port)})
 				}
-				endpointsMap[svcId] = endpoints
+				endpointsMap[svcId] = shuffle(endpoints)
 			}
 		}
 	}
@@ -856,5 +865,7 @@ func NewNetworkServicesController(clientset *kubernetes.Clientset, config *optio
 	watchers.EndpointsWatcher.RegisterHandler(&nsc)
 	watchers.ServiceWatcher.RegisterHandler(&nsc)
 
+	rand.Seed(time.Now().UnixNano())
+
 	return &nsc, nil
 }