enable dynamic backend configuration by default

cmd/nginx/flags.go

@@ -143,7 +143,7 @@ extension for this to succeed.`)
 			`Customized address to set as the load-balancer status of Ingress objects this controller satisfies.
 Requires the update-status parameter.`)
 
-		dynamicConfigurationEnabled = flags.Bool("enable-dynamic-configuration", false,
+		dynamicConfigurationEnabled = flags.Bool("enable-dynamic-configuration", true,
 			`Dynamically refresh backends on topology changes instead of reloading NGINX.
 Feature backed by OpenResty Lua libraries.`)
 

docs/user-guide/cli-arguments.md

@@ -15,7 +15,7 @@ They are set in the container spec of the `nginx-ingress-controller` Deployment
 | --default-server-port int         | Port to use for exposing the default server (catch-all). (default 8181) |
 | --default-ssl-certificate string  | Secret containing a SSL certificate to be used by the default HTTPS server (catch-all). Takes the form "namespace/name". |
 | --election-id string              | Election id to use for Ingress status updates. (default "ingress-controller-leader") |
-| --enable-dynamic-configuration    | Dynamically refresh backends on topology changes instead of reloading NGINX. Feature backed by OpenResty Lua libraries. |
+| --enable-dynamic-configuration    | Dynamically refresh backends on topology changes instead of reloading NGINX. Feature backed by OpenResty Lua libraries. (enabled by default) |
 | --enable-ssl-chain-completion     | Autocomplete SSL certificate chains with missing intermediate CA certificates. A valid certificate chain is required to enable OCSP stapling. Certificates uploaded to Kubernetes must have the "Authority Information Access" X.509 v3 extension for this to succeed. (default true) |
 | --enable-ssl-passthrough          | Enable SSL Passthrough. |
 | --force-namespace-isolation       | Force namespace isolation. Prevents Ingress objects from referencing Secrets and ConfigMaps located in a different namespace than their own. May be used together with watch-namespace. |

docs/user-guide/nginx-configuration/configmap.md

@@ -92,7 +92,7 @@ The following table shows a configuration option's name, type, and the default v
 |[worker-processes](#worker-processes)|string|`<Number of CPUs>`|
 |[worker-cpu-affinity](#worker-cpu-affinity)|string|""|
 |[worker-shutdown-timeout](#worker-shutdown-timeout)|string|"10s"|
-|[load-balance](#load-balance)|string|"least_conn"|
+|[load-balance](#load-balance)|string|"round_robin"|
 |[variables-hash-bucket-size](#variables-hash-bucket-size)|int|128|
 |[variables-hash-max-size](#variables-hash-max-size)|int|2048|
 |[upstream-keepalive-connections](#upstream-keepalive-connections)|int|32|
@@ -520,11 +520,11 @@ Sets the algorithm to use for load balancing.
 The value can either be:
 
 - round_robin: to use the default round robin loadbalancer
-- least_conn: to use the least connected method
+- least_conn: to use the least connected method (_note_ that this is available only in non-dynamic mode: `--enable-dynamic-configuration=false`)
-- ip_hash: to use a hash of the server for routing.
+- ip_hash: to use a hash of the server for routing (_note_ that this is available only in non-dynamic mode: `--enable-dynamic-configuration=false`, but alternatively you can consider using `nginx.ingress.kubernetes.io/upstream-hash-by`)
-- ewma: to use the peak ewma method for routing (only available with `enable-dynamic-configuration` flag) 
+- ewma: to use the Peak EWMA method for routing ([implementation](https://github.com/kubernetes/ingress-nginx/blob/master/rootfs/etc/nginx/lua/balancer/ewma.lua))
 
-The default is least_conn.
+The default is `round_robin`.
 
 _References:_
 [http://nginx.org/en/docs/http/load_balancing.html](http://nginx.org/en/docs/http/load_balancing.html)

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 ""
 	}