From bc26d9f0de3cb82604ffad36e5aca34a343187e2 Mon Sep 17 00:00:00 2001
From: Ludovic Fernandez <ldez@users.noreply.github.com>
Date: Tue, 22 May 2018 09:20:03 +0200
Subject: [PATCH] Enhance Load-balancing method validation log.

---
 server/server.go |  2 +-
 types/types.go   | 21 +++++++++++++--------
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/server/server.go b/server/server.go
index 201368be9..b55c1d2b1 100644
--- a/server/server.go
+++ b/server/server.go
@@ -1438,7 +1438,7 @@ func configureBackends(backends map[string]*types.Backend) {
 				}
 			}
 		} else {
-			log.Debugf("Validation of load balancer method for backend %s failed: %s. Using default method wrr.", backendName, err)
+			log.Debugf("Backend %s: %v", backendName, err)
 
 			var stickiness *types.Stickiness
 			if backend.LoadBalancer != nil {
diff --git a/types/types.go b/types/types.go
index 518d5a365..eed737bee 100644
--- a/types/types.go
+++ b/types/types.go
@@ -211,16 +211,21 @@ var loadBalancerMethodNames = []string{
 
 // NewLoadBalancerMethod create a new LoadBalancerMethod from a given LoadBalancer.
 func NewLoadBalancerMethod(loadBalancer *LoadBalancer) (LoadBalancerMethod, error) {
-	var method string
-	if loadBalancer != nil {
-		method = loadBalancer.Method
-		for i, name := range loadBalancerMethodNames {
-			if strings.EqualFold(name, method) {
-				return LoadBalancerMethod(i), nil
-			}
+	if loadBalancer == nil {
+		return Wrr, errors.New("no load-balancer defined, fallback to 'wrr' method")
+	}
+
+	if len(loadBalancer.Method) == 0 {
+		return Wrr, errors.New("no load-balancing method defined, fallback to 'wrr' method")
+	}
+
+	for i, name := range loadBalancerMethodNames {
+		if strings.EqualFold(name, loadBalancer.Method) {
+			return LoadBalancerMethod(i), nil
 		}
 	}
-	return Wrr, fmt.Errorf("invalid load-balancing method '%s'", method)
+
+	return Wrr, fmt.Errorf("invalid load-balancing method %q, fallback to 'wrr' method", loadBalancer.Method)
 }
 
 // Configurations is for currentConfigurations Map