Add docs URL to IP check error

internal/fields/testdata/fields/fields.yml

@@ -11,3 +11,5 @@
     - name: constant
       type: constant_keyword
       value: correct
+    - name: ip_address
+      type: ip

internal/fields/testdata/ip-address-allowed.json

@@ -0,0 +1,5 @@
+{
+  "foo": {
+    "ip_address": "::"
+  }
+}

internal/fields/testdata/ip-address-forbidden.json

@@ -0,0 +1,5 @@
+{
+  "foo": {
+    "ip_address": "98.76.54.32"
+  }
+}

internal/fields/validate.go

@@ -121,7 +121,7 @@ var allowedGeoIPs string
 func initializeAllowedIPsList() map[string]struct{} {
 	m := map[string]struct{}{
 		"0.0.0.0": {}, "255.255.255.255": {},
-		"0:0:0:0:0:0:0:0": {}, "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff": {},
+		"0:0:0:0:0:0:0:0": {}, "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff": {}, "::": {},
 	}
 	for _, ip := range strings.Split(allowedGeoIPs, "\n") {
 		ip = strings.Trim(ip, " \n\t")
@@ -363,7 +363,7 @@ func (v *Validator) parseElementValue(key string, definition FieldDefinition, va
 		}
 
 		if v.enabledAllowedIPCheck && !v.isAllowedIPValue(valStr) {
-			return fmt.Errorf("the IP %q is not one of the allowed test IPs", valStr)
+			return fmt.Errorf("the IP %q is not one of the allowed test IPs (see: https://github.com/elastic/elastic-package/blob/master/internal/fields/_static/allowed_geo_ips.txt)", valStr)
 		}
 	case "float", "long", "double":
 		_, valid = val.(float64)

internal/fields/validate_test.go

@@ -61,7 +61,7 @@ func TestValidate_WithNumericKeywordFields(t *testing.T) {
 	require.Empty(t, errs)
 }
 
-func TestValidate_constant_keyword(t *testing.T) {
+func TestValidate_constantKeyword(t *testing.T) {
 	validator, err := CreateValidatorForDataStream("testdata")
 	require.NoError(t, err)
 	require.NotNil(t, validator)
@@ -75,6 +75,21 @@ func TestValidate_constant_keyword(t *testing.T) {
 	require.Empty(t, errs)
 }
 
+func TestValidate_ipAddress(t *testing.T) {
+	validator, err := CreateValidatorForDataStream("testdata", WithEnabledAllowedIPCheck())
+	require.NoError(t, err)
+	require.NotNil(t, validator)
+
+	e := readSampleEvent(t, "testdata/ip-address-forbidden.json")
+	errs := validator.ValidateDocumentBody(e)
+	require.Len(t, errs, 1)
+	require.Contains(t, errs[0].Error(), `the IP "98.76.54.32" is not one of the allowed test IPs`)
+
+	e = readSampleEvent(t, "testdata/ip-address-allowed.json")
+	errs = validator.ValidateDocumentBody(e)
+	require.Empty(t, errs)
+}
+
 func Test_parseElementValue(t *testing.T) {
 	for _, test := range []struct {
 		key        string