enable dynamic backend configuration by default

internal/ingress/controller/config/config.go

@@ -77,7 +77,7 @@ const (
 	sslSessionCacheSize = "10m"
 
 	// Default setting for load balancer algorithm
-	defaultLoadBalancerAlgorithm = "least_conn"
+	defaultLoadBalancerAlgorithm = ""
 
 	// Parameters for a shared memory zone that will keep states for various keys.
 	// http://nginx.org/en/docs/http/ngx_http_limit_conn_module.html#limit_conn_zone

internal/ingress/controller/template/configmap_test.go

@@ -155,7 +155,7 @@ func TestMergeConfigMapToStruct(t *testing.T) {
 func TestDefaultLoadBalance(t *testing.T) {
 	conf := map[string]string{}
 	to := ReadConfig(conf)
-	if to.LoadBalanceAlgorithm != "least_conn" {
+	if to.LoadBalanceAlgorithm != "" {
 		t.Errorf("default load balance algorithm wrong")
 	}
 }

internal/ingress/controller/template/template.go

@@ -378,7 +378,7 @@ func buildLoadBalancingConfig(b interface{}, fallbackLoadBalancing string) strin
 		return fmt.Sprintf("%s;", backend.LoadBalancing)
 	}
 
-	if fallbackLoadBalancing == "round_robin" {
+	if fallbackLoadBalancing == "round_robin" || fallbackLoadBalancing == "" {
 		return ""
 	}