Add load balancing method to transport server config

cmd/nginx-ingress/main.go

@@ -605,7 +605,7 @@ func main() {
 		templateExecutorV2, *nginxPlus, isWildcardEnabled, plusCollector, *enablePrometheusMetrics, latencyCollector, *enableLatencyMetrics)
 	controllerNamespace := os.Getenv("POD_NAMESPACE")
 
-	transportServerValidator := cr_validation.NewTransportServerValidator(*enableTLSPassthrough, *enableSnippets)
+	transportServerValidator := cr_validation.NewTransportServerValidator(*enableTLSPassthrough, *enableSnippets, *nginxPlus)
 	virtualServerValidator := cr_validation.NewVirtualServerValidator(*nginxPlus)
 
 	lbcInput := k8s.NewLoadBalancerControllerInput{

deployments/common/crds-v1beta1/k8s.nginx.org_transportservers.yaml

@@ -0,0 +1,147 @@
+apiVersion: apiextensions.k8s.io/v1beta1
+kind: CustomResourceDefinition
+metadata:
+  annotations:
+    controller-gen.kubebuilder.io/version: v0.5.0
+  creationTimestamp: null
+  name: transportservers.k8s.nginx.org
+spec:
+  additionalPrinterColumns:
+    - JSONPath: .status.state
+      description: Current state of the TransportServer. If the resource has a valid status, it means it has been validated and accepted by the Ingress Controller.
+      name: State
+      type: string
+    - JSONPath: .status.reason
+      name: Reason
+      type: string
+    - JSONPath: .metadata.creationTimestamp
+      name: Age
+      type: date
+  group: k8s.nginx.org
+  names:
+    kind: TransportServer
+    listKind: TransportServerList
+    plural: transportservers
+    shortNames:
+      - ts
+    singular: transportserver
+  preserveUnknownFields: false
+  scope: Namespaced
+  subresources:
+    status: {}
+  validation:
+    openAPIV3Schema:
+      description: TransportServer defines the TransportServer resource.
+      type: object
+      properties:
+        apiVersion:
+          description: 'APIVersion defines the versioned schema of this representation of an object. Servers should convert recognized schemas to the latest internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources'
+          type: string
+        kind:
+          description: 'Kind is a string value representing the REST resource this object represents. Servers may infer this from the endpoint the client submits requests to. Cannot be updated. In CamelCase. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds'
+          type: string
+        metadata:
+          type: object
+        spec:
+          description: TransportServerSpec is the spec of the TransportServer resource.
+          type: object
+          properties:
+            action:
+              description: Action defines an action.
+              type: object
+              properties:
+                pass:
+                  type: string
+            host:
+              type: string
+            ingressClassName:
+              type: string
+            listener:
+              description: TransportServerListener defines a listener for a TransportServer.
+              type: object
+              properties:
+                name:
+                  type: string
+                protocol:
+                  type: string
+            serverSnippets:
+              type: string
+            sessionParameters:
+              description: SessionParameters defines session parameters.
+              type: object
+              properties:
+                timeout:
+                  type: string
+            upstreamParameters:
+              description: UpstreamParameters defines parameters for an upstream.
+              type: object
+              properties:
+                connectTimeout:
+                  type: string
+                nextUpstream:
+                  type: boolean
+                nextUpstreamTimeout:
+                  type: string
+                nextUpstreamTries:
+                  type: integer
+                udpRequests:
+                  type: integer
+                udpResponses:
+                  type: integer
+            upstreams:
+              type: array
+              items:
+                description: Upstream defines an upstream.
+                type: object
+                properties:
+                  failTimeout:
+                    type: string
+                  healthCheck:
+                    description: HealthCheck defines the parameters for active Upstream HealthChecks.
+                    type: object
+                    properties:
+                      enable:
+                        type: boolean
+                      fails:
+                        type: integer
+                      interval:
+                        type: string
+                      jitter:
+                        type: string
+                      passes:
+                        type: integer
+                      port:
+                        type: integer
+                      timeout:
+                        type: string
+                  loadBalancingMethod:
+                    type: string
+                  maxFails:
+                    type: integer
+                  name:
+                    type: string
+                  port:
+                    type: integer
+                  service:
+                    type: string
+        status:
+          description: TransportServerStatus defines the status for the TransportServer resource.
+          type: object
+          properties:
+            message:
+              type: string
+            reason:
+              type: string
+            state:
+              type: string
+  version: v1alpha1
+  versions:
+    - name: v1alpha1
+      served: true
+      storage: true
+status:
+  acceptedNames:
+    kind: ""
+    plural: ""
+  conditions: []
+  storedVersions: []

deployments/common/crds/k8s.nginx.org_transportservers.yaml

@@ -113,6 +113,8 @@ spec:
                             type: integer
                           timeout:
                             type: string
+                      loadBalancingMethod:
+                        type: string
                       maxFails:
                         type: integer
                       name:

deployments/helm-chart/crds/k8s.nginx.org_transportservers.yaml

@@ -113,6 +113,8 @@ spec:
                             type: integer
                           timeout:
                             type: string
+                      loadBalancingMethod:
+                        type: string
                       maxFails:
                         type: integer
                       name:

docs-web/configuration/transportserver-resource.md

@@ -169,6 +169,7 @@ service: secure-app
 port: 8443
 maxFails: 3
 failTimeout: 30s
+loadBalancingMethod: least_conn
 ```
 
 ```eval_rst
@@ -203,6 +204,10 @@ failTimeout: 30s
      - The health check configuration for the Upstream. See the `health_check <https://nginx.org/en/docs/stream/ngx_stream_upstream_hc_module.html#health_check>`_ directive. Note: this feature is supported only in NGINX Plus.
      - `healthcheck <#upstream-healthcheck>`_
      - No
+   * - ``loadBalancingMethod``
+     - The method used to load balance the upstream servers. By default, connections are distributed between the servers using a weighted round-robin balancing method. See the `upstream <http://nginx.org/en/docs/stream/ngx_stream_upstream_module.html#upstream>`_ section for available methods and their details.
+     - ``string``
+     - No
 
 ```
 

internal/configs/parsing_helpers.go

@@ -154,12 +154,12 @@ func validateHashLBMethod(method string) (string, error) {
 	keyWords := strings.Split(method, " ")
 
 	if keyWords[0] == "hash" {
-		if len(keyWords) == 2 || len(keyWords) == 3 && keyWords[2] == "consistent" {
+		if len(keyWords) == 2 || (len(keyWords) == 3 && keyWords[2] == "consistent") {
 			return method, nil
 		}
 	}
 
-	return "", fmt.Errorf("Invalid load balancing method: %q", method)
+	return "", fmt.Errorf("invalid load balancing method: %q", method)
 }
 
 // ParseBool ensures that the string value is a valid bool

internal/configs/transportserver.go

@@ -190,7 +190,21 @@ func generateStreamUpstream(upstream *conf_v1alpha1.Upstream, upstreamNamer *ups
 	}
 
 	return version2.StreamUpstream{
-		Name:    name,
-		Servers: upsServers,
+		Name:                name,
+		Servers:             upsServers,
+		LoadBalancingMethod: generateLoadBalancingMethod(upstream.LoadBalancingMethod),
 	}
 }
+
+func generateLoadBalancingMethod(method string) string {
+	if method == "" {
+		// By default, if unspecified, Nginx uses the 'round_robin' load balancing method.
+		// We override this default which suits the Ingress Controller better.
+		return "random two least_conn"
+	}
+	if method == "round_robin" {
+		// By default, Nginx uses round robin. We select this method by not specifying any method.
+		return ""
+	}
+	return method
+}

internal/configs/transportserver_test.go

@@ -112,6 +112,7 @@ func TestGenerateTransportServerConfigForTCPSnippets(t *testing.T) {
 					ResourceNamespace: "default",
 					Service:           "tcp-app-svc",
 				},
+				LoadBalancingMethod: "random two least_conn",
 			},
 		},
 		Server: version2.StreamServer{
@@ -196,6 +197,7 @@ func TestGenerateTransportServerConfigForTCP(t *testing.T) {
 					ResourceNamespace: "default",
 					Service:           "tcp-app-svc",
 				},
+				LoadBalancingMethod: "random two least_conn",
 			},
 		},
 		Server: version2.StreamServer{
@@ -279,6 +281,7 @@ func TestGenerateTransportServerConfigForTLSPasstrhough(t *testing.T) {
 					ResourceNamespace: "default",
 					Service:           "tcp-app-svc",
 				},
+				LoadBalancingMethod: "random two least_conn",
 			},
 		},
 		Server: version2.StreamServer{
@@ -368,6 +371,7 @@ func TestGenerateTransportServerConfigForUDP(t *testing.T) {
 					ResourceNamespace: "default",
 					Service:           "udp-app-svc",
 				},
+				LoadBalancingMethod: "random two least_conn",
 			},
 		},
 		Server: version2.StreamServer{

internal/configs/version2/nginx-plus.transportserver.tmpl

@@ -2,7 +2,9 @@
 upstream {{ $u.Name }} {
     zone {{ $u.Name }} 256k;
 
-    random two least_conn;
+    {{ if $u.LoadBalancingMethod }}
+    {{ $u.LoadBalancingMethod }};
+    {{ end }}
 
     {{ range $s := $u.Servers }}
     server {{ $s.Address }} max_fails={{ $s.MaxFails }} fail_timeout={{ $s.FailTimeout }};

internal/configs/version2/nginx.transportserver.tmpl

@@ -2,7 +2,9 @@
 upstream {{ $u.Name }} {
     zone {{ $u.Name }} 256k;
 
-    random two least_conn;
+    {{ if $u.LoadBalancingMethod }}
+    {{ $u.LoadBalancingMethod }};
+    {{ end }}
 
     {{ range $s := $u.Servers }}
     server {{ $s.Address }} max_fails={{ $s.MaxFails }} fail_timeout={{ $s.FailTimeout }};

internal/configs/version2/stream.go

@@ -8,9 +8,10 @@ type TransportServerConfig struct {
 
 // StreamUpstream defines a stream upstream.
 type StreamUpstream struct {
-	Name           string
-	Servers        []StreamUpstreamServer
-	UpstreamLabels UpstreamLabels
+	Name                string
+	Servers             []StreamUpstreamServer
+	UpstreamLabels      UpstreamLabels
+	LoadBalancingMethod string
 }
 
 // StreamUpstreamServer defines a stream upstream server.

internal/k8s/configuration_test.go

@@ -33,7 +33,7 @@ func createTestConfiguration() *Configuration {
 			80:  true,
 			443: true,
 		}),
-		validation.NewTransportServerValidator(isTLSPassthroughEnabled, snippetsEnabled),
+		validation.NewTransportServerValidator(isTLSPassthroughEnabled, snippetsEnabled, isPlus),
 		isTLSPassthroughEnabled,
 	)
 }

pkg/apis/configuration/v1alpha1/types.go

@@ -84,12 +84,13 @@ type TransportServerListener struct {
 
 // Upstream defines an upstream.
 type Upstream struct {
-	Name        string       `json:"name"`
-	Service     string       `json:"service"`
-	Port        int          `json:"port"`
-	FailTimeout string       `json:"failTimeout"`
-	MaxFails    *int         `json:"maxFails"`
-	HealthCheck *HealthCheck `json:"healthCheck"`
+	Name                string       `json:"name"`
+	Service             string       `json:"service"`
+	Port                int          `json:"port"`
+	FailTimeout         string       `json:"failTimeout"`
+	MaxFails            *int         `json:"maxFails"`
+	HealthCheck         *HealthCheck `json:"healthCheck"`
+	LoadBalancingMethod string       `json:"loadBalancingMethod"`
 }
 
 // HealthCheck defines the parameters for active Upstream HealthChecks.