common/helpers: make validation work for SubnetMap

common/helpers/validator.go

@@ -5,6 +5,7 @@ package helpers
 
 import (
 	"net"
+	"reflect"
 	"strconv"
 
 	"github.com/go-playground/validator/v10"
@@ -13,6 +14,20 @@ import (
 // Validate is a validator instance to be used everywhere.
 var Validate *validator.Validate
 
+// RegisterSubnetMapValidation register a new SubnetMap[] type for
+// validation. As validator requires an explicit type, we cannot just
+// register all subnetmaps.
+func RegisterSubnetMapValidation[V any]() {
+	var zero SubnetMap[V]
+	validatorFunc := func(field reflect.Value) interface{} {
+		if subnetMap, ok := field.Interface().(SubnetMap[V]); ok {
+			return subnetMap.ToMap()
+		}
+		return nil
+	}
+	Validate.RegisterCustomTypeFunc(validatorFunc, zero)
+}
+
 // isListen validates a <dns>:<port> combination for fields typically used for listening address
 func isListen(fl validator.FieldLevel) bool {
 	val := fl.Field().String()
@@ -35,4 +50,5 @@ func isListen(fl validator.FieldLevel) bool {
 func init() {
 	Validate = validator.New()
 	Validate.RegisterValidation("listen", isListen)
+	RegisterSubnetMapValidation[string]()
 }

common/helpers/validator_test.go

@@ -37,3 +37,52 @@ func TestListenValidator(t *testing.T) {
 		}
 	}
 }
+
+func TestSubnetMapValidator(t *testing.T) {
+	type SomeStruct struct {
+		Blip *helpers.SubnetMap[string] `validate:"min=2,dive,min=3"`
+	}
+
+	cases := []struct {
+		Description string
+		Value       interface{}
+		Error       bool
+	}{
+		{
+			Description: "Valid SomeStruct",
+			Value: SomeStruct{
+				Blip: helpers.MustNewSubnetMap(map[string]string{
+					"2001:db8::/64":   "hello",
+					"2001:db8:1::/64": "bye",
+				}),
+			},
+		}, {
+			Description: "Missing one key",
+			Value: SomeStruct{
+				Blip: helpers.MustNewSubnetMap(map[string]string{
+					"2001:db8::/64": "hello",
+				}),
+			},
+			Error: true,
+		}, {
+			Description: "One value is too short",
+			Value: SomeStruct{
+				Blip: helpers.MustNewSubnetMap(map[string]string{
+					"2001:db8::/64":   "he",
+					"2001:db8:1::/64": "bye",
+				}),
+			},
+			Error: true,
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.Description, func(t *testing.T) {
+			err := helpers.Validate.Struct(tc.Value)
+			if err != nil && !tc.Error {
+				t.Fatalf("Validate() error:\n%+v", err)
+			} else if err == nil && tc.Error {
+				t.Fatal("Validate() did not error")
+			}
+		})
+	}
+}

inlet/snmp/config.go

@@ -191,4 +191,5 @@ func init() {
 	helpers.AddMapstructureUnmarshallerHook(ConfigurationUnmarshallerHook())
 	helpers.AddMapstructureUnmarshallerHook(helpers.SubnetMapUnmarshallerHook[string]())
 	helpers.AddMapstructureUnmarshallerHook(helpers.SubnetMapUnmarshallerHook[SecurityParameters]())
+	helpers.RegisterSubnetMapValidation[SecurityParameters]()
 }