Support NativeLB option in GatewayAPI provider

Co-authored-by: Kevin Pollet <pollet.kevin@gmail.com>

pkg/provider/kubernetes/gateway/annotations_test.go

@@ -0,0 +1,89 @@
+package gateway
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_parseServiceConfig(t *testing.T) {
+	testCases := []struct {
+		desc        string
+		annotations map[string]string
+		expected    ServiceConfig
+	}{
+		{
+			desc: "service annotations",
+			annotations: map[string]string{
+				"ingress.kubernetes.io/foo":   "bar",
+				"traefik.io/foo":              "bar",
+				"traefik.io/service.nativelb": "true",
+			},
+			expected: ServiceConfig{
+				Service: Service{
+					NativeLB: true,
+				},
+			},
+		},
+		{
+			desc:        "empty map",
+			annotations: map[string]string{},
+			expected:    ServiceConfig{},
+		},
+		{
+			desc:        "nil map",
+			annotations: nil,
+			expected:    ServiceConfig{},
+		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			cfg, err := parseServiceAnnotations(test.annotations)
+			require.NoError(t, err)
+
+			assert.Equal(t, test.expected, cfg)
+		})
+	}
+}
+
+func Test_convertAnnotations(t *testing.T) {
+	testCases := []struct {
+		desc        string
+		annotations map[string]string
+		expected    map[string]string
+	}{
+		{
+			desc: "service annotations",
+			annotations: map[string]string{
+				"traefik.io/service.nativelb": "true",
+			},
+			expected: map[string]string{
+				"traefik.service.nativelb": "true",
+			},
+		},
+		{
+			desc:        "empty map",
+			annotations: map[string]string{},
+			expected:    nil,
+		},
+		{
+			desc:        "nil map",
+			annotations: nil,
+			expected:    nil,
+		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			labels := convertAnnotations(test.annotations)
+
+			assert.Equal(t, test.expected, labels)
+		})
+	}
+}