update upstream settings policy API

Author: salonichf5

apis/v1alpha1/upstreamsettingspolicy_types.go

@@ -51,6 +51,12 @@ type UpstreamSettingsPolicySpec struct {
 	// +optional
 	KeepAlive *UpstreamKeepAlive `json:"keepAlive,omitempty"`
 
+	// LoadBalancingMethod specifies the load balancing algorithm to be used for the upstream.
+	//
+	// +optional
+	// +kubebuilder:default:=random two least_conn
+	LoadBalancingMethod *LoadBalancingType `json:"loadBalancingMethod,omitempty"`
+
 	// TargetRefs identifies API object(s) to apply the policy to.
 	// Objects must be in the same namespace as the policy.
 	// Support: Service
@@ -98,3 +104,22 @@ type UpstreamKeepAlive struct {
 	// +optional
 	Timeout *Duration `json:"timeout,omitempty"`
 }
+
+// LoadBalancingType defines the supported load balancing methods.
+//
+// +kubebuilder:validation:Enum=ip_hash;random two least_conn
+type LoadBalancingType string
+
+const (
+	// LoadBalancingTypeIPHash enables IP hash-based load balancing,
+	// ensuring requests from the same client IP are routed to the same upstream server.
+	// NGINX directive: https://nginx.org/en/docs/http/ngx_http_upstream_module.html#ip_hash
+	LoadBalancingTypeIPHash LoadBalancingType = "ip_hash"
+
+	// LoadBalancingTypeRandomTwoLeastConnection enables a variation of least-connections
+	// balancing that randomly selects two servers and forwards traffic to the one with
+	// fewer active connections.
+	// NGINX directive least_conn: https://nginx.org/en/docs/http/ngx_http_upstream_module.html#least_conn
+	// NGINX directive random: https://nginx.org/en/docs/http/ngx_http_upstream_module.html#random
+	LoadBalancingTypeRandomTwoLeastConnection LoadBalancingType = "random two least_conn"
+)

apis/v1alpha1/zz_generated.deepcopy.go

@@ -85,6 +85,14 @@ spec:
                     pattern: ^[0-9]{1,4}(ms|s|m|h)?$
                     type: string
                 type: object
+              loadBalancingMethod:
+                default: random two least_conn
+                description: LoadBalancingMethod specifies the load balancing algorithm
+                  to be used for the upstream.
+                enum:
+                - ip_hash
+                - random two least_conn
+                type: string
               targetRefs:
                 description: |-
                   TargetRefs identifies API object(s) to apply the policy to.

config/crd/bases/gateway.nginx.org_upstreamsettingspolicies.yaml

@@ -9595,6 +9595,14 @@ spec:
                     pattern: ^[0-9]{1,4}(ms|s|m|h)?$
                     type: string
                 type: object
+              loadBalancingMethod:
+                default: random two least_conn
+                description: LoadBalancingMethod specifies the load balancing algorithm
+                  to be used for the upstream.
+                enum:
+                - ip_hash
+                - random two least_conn
+                type: string
               targetRefs:
                 description: |-
                   TargetRefs identifies API object(s) to apply the policy to.

deploy/crds.yaml

@@ -372,3 +372,64 @@ func TestUpstreamSettingsPolicyTargetRefNameUniqueness(t *testing.T) {
 		})
 	}
 }
+
+func TestUpstreamSettingsPolicy_LoadBalancingMethodTypes(t *testing.T) {
+	t.Parallel()
+	k8sClient := getKubernetesClient(t)
+
+	convertLBType := func(s ngfAPIv1alpha1.LoadBalancingType) *ngfAPIv1alpha1.LoadBalancingType {
+		return &s
+	}
+
+	tests := []struct {
+		spec       ngfAPIv1alpha1.UpstreamSettingsPolicySpec
+		name       string
+		wantErrors []string
+	}{
+		{
+			name: "Valid LoadBalancingType 'random two least_conn' is allowed",
+			spec: ngfAPIv1alpha1.UpstreamSettingsPolicySpec{
+				LoadBalancingMethod: convertLBType(ngfAPIv1alpha1.LoadBalancingTypeRandomTwoLeastConnection),
+			},
+		},
+		{
+			name: "Valid LoadBalancingType 'ip_hash' is allowed",
+			spec: ngfAPIv1alpha1.UpstreamSettingsPolicySpec{
+				LoadBalancingMethod: convertLBType(ngfAPIv1alpha1.LoadBalancingTypeIPHash),
+			},
+		},
+		{
+			name: "Invalid LoadBalancingType 'invalid_type' is not allowed",
+			wantErrors: []string{
+				"spec.loadBalancingMethod: Unsupported value: " +
+					"\"invalid_type\": supported values: \"ip_hash\", \"random two least_conn\"",
+			},
+			spec: ngfAPIv1alpha1.UpstreamSettingsPolicySpec{
+				LoadBalancingMethod: convertLBType("invalid_type"),
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			tt.spec.TargetRefs = []gatewayv1.LocalPolicyTargetReference{
+				{
+					Kind:  serviceKind,
+					Group: coreGroup,
+					Name:  gatewayv1.ObjectName(uniqueResourceName(testTargetRefName)),
+				},
+			}
+
+			upstreamSettingsPolicy := &ngfAPIv1alpha1.UpstreamSettingsPolicy{
+				ObjectMeta: controllerruntime.ObjectMeta{
+					Name:      uniqueResourceName(testResourceName),
+					Namespace: defaultNamespace,
+				},
+				Spec: tt.spec,
+			}
+			validateCrd(t, tt.wantErrors, upstreamSettingsPolicy, k8sClient)
+		})
+	}
+}