From 1dbbfa0638218597c37c805b5c2705db48d765da Mon Sep 17 00:00:00 2001
From: Joe Betz <jpbetz@google.com>
Date: Fri, 6 Dec 2024 21:00:25 -0500
Subject: [PATCH] Ignore unknown k8s:validation comments tags

---
 pkg/generators/markers.go      | 42 +++++++++++++++++++++++++++++++---
 pkg/generators/markers_test.go | 22 +++++++++++++++++-
 pkg/generators/openapi_test.go |  3 ++-
 3 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/pkg/generators/markers.go b/pkg/generators/markers.go
index c4dd67d3b..00627e9e6 100644
--- a/pkg/generators/markers.go
+++ b/pkg/generators/markers.go
@@ -20,9 +20,11 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"reflect"
 	"regexp"
 	"strconv"
 	"strings"
+	"sync"
 
 	"k8s.io/gengo/v2/types"
 	openapi "k8s.io/kube-openapi/pkg/common"
@@ -61,6 +63,26 @@ func (c *CELTag) Validate() error {
 	return nil
 }
 
+func isKnownTagCommentKey(key string) bool {
+	commentTag, _, _ := strings.Cut(key, ":")
+	_, ok := tagKeys()[commentTag]
+	return ok
+}
+
+var tagKeys = sync.OnceValue(func() map[string]struct{} {
+	result := map[string]struct{}{}
+	t := reflect.TypeOf(commentTags{})
+	for i := 0; i < t.NumField(); i++ {
+		field := t.Field(i)
+		if jsonTag := field.Tag.Get("json"); jsonTag != "" {
+			if key, _, _ := strings.Cut(jsonTag, ","); key != "" {
+				result[key] = struct{}{}
+			}
+		}
+	}
+	return result
+})
+
 // commentTags represents the parsed comment tags for a given type. These types are then used to generate schema validations.
 // These only include the newer prefixed tags. The older tags are still supported,
 // but are not included in this struct. Comment Tags are transformed into a
@@ -385,13 +407,24 @@ func memberWithJSONName(t *types.Type, key string) *types.Member {
 	return nil
 }
 
+type ParseCommentTagsOptions struct {
+	IgnoreUnknown bool
+}
+
 // Parses the given comments into a CommentTags type. Validates the parsed comment tags, and returns the result.
 // Accepts an optional type to validate against, and a prefix to filter out markers not related to validation.
 // Accepts a prefix to filter out markers not related to validation.
 // Returns any errors encountered while parsing or validating the comment tags.
-func ParseCommentTags(t *types.Type, comments []string, prefix string) (*spec.Schema, error) {
+func ParseCommentTags(t *types.Type, comments []string, prefix string, opts ...ParseCommentTagsOptions) (*spec.Schema, error) {
+	options := ParseCommentTagsOptions{}
+	if len(opts) > 0 {
+		options = opts[0]
+		if len(opts) > 1 {
+			return nil, fmt.Errorf("only one option is allowed")
+		}
+	}
 
-	markers, err := parseMarkers(comments, prefix)
+	markers, err := parseMarkers(comments, prefix, options.IgnoreUnknown)
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse marker comments: %w", err)
 	}
@@ -597,7 +630,7 @@ func extractCommentTags(marker string, lines []string) (map[string]string, error
 // Accepts a prefix to filter out markers not related to validation.
 // The prefix is removed from the key in the returned map.
 // Empty keys and invalid values will return errors, refs are currently unsupported and will be skipped.
-func parseMarkers(markerComments []string, prefix string) (map[string]any, error) {
+func parseMarkers(markerComments []string, prefix string, ignoreUnknown bool) (map[string]any, error) {
 	markers, err := extractCommentTags(prefix, markerComments)
 	if err != nil {
 		return nil, err
@@ -606,6 +639,9 @@ func parseMarkers(markerComments []string, prefix string) (map[string]any, error
 	// Parse the values as JSON
 	result := map[string]any{}
 	for key, value := range markers {
+		if ignoreUnknown && !isKnownTagCommentKey(key) {
+			continue
+		}
 		var unmarshalled interface{}
 
 		if len(key) == 0 {
diff --git a/pkg/generators/markers_test.go b/pkg/generators/markers_test.go
index 28f6e551a..49d1ca329 100644
--- a/pkg/generators/markers_test.go
+++ b/pkg/generators/markers_test.go
@@ -19,6 +19,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
+
 	"k8s.io/gengo/v2/types"
 	"k8s.io/kube-openapi/pkg/generators"
 	"k8s.io/kube-openapi/pkg/validation/spec"
@@ -626,6 +627,7 @@ func TestCommentTags_Validate(t *testing.T) {
 		comments     []string
 		t            *types.Type
 		errorMessage string
+		options      generators.ParseCommentTagsOptions
 	}{
 		{
 			name: "invalid minimum type",
@@ -960,11 +962,29 @@ func TestCommentTags_Validate(t *testing.T) {
 			},
 			errorMessage: `failed to validate property "name": pattern can only be used on string types`,
 		},
+		{
+			name: "ignore unknown field with unparsable value",
+			comments: []string{
+				`+k8s:validation:xyz=a=b`, // a=b is not a valid value
+			},
+			t: &types.Type{
+				Kind: types.Struct,
+				Name: types.Name{Name: "struct"},
+				Members: []types.Member{
+					{
+						Name: "name",
+						Type: types.String,
+						Tags: `json:"name"`,
+					},
+				},
+			},
+			options: generators.ParseCommentTagsOptions{IgnoreUnknown: true},
+		},
 	}
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-			_, err := generators.ParseCommentTags(tc.t, tc.comments, "+k8s:validation:")
+			_, err := generators.ParseCommentTags(tc.t, tc.comments, "+k8s:validation:", tc.options)
 			if tc.errorMessage != "" {
 				require.Error(t, err)
 				require.Equal(t, "invalid marker comments: "+tc.errorMessage, err.Error())
diff --git a/pkg/generators/openapi_test.go b/pkg/generators/openapi_test.go
index e53292129..55be4c557 100644
--- a/pkg/generators/openapi_test.go
+++ b/pkg/generators/openapi_test.go
@@ -27,6 +27,7 @@ import (
 	"github.com/google/go-cmp/cmp"
 	"golang.org/x/tools/go/packages"
 	"golang.org/x/tools/go/packages/packagestest"
+
 	"k8s.io/gengo/v2/generator"
 	"k8s.io/gengo/v2/namer"
 	"k8s.io/gengo/v2/parser"
@@ -2386,7 +2387,7 @@ func TestMarkerComments(t *testing.T) {
 			// +k8s:validation:pattern="^foo$[0-9]+"
 			StringValue string
 
-			// +k8s:validation:maxitems=10
+			// +k8s:validation:maxItems=10
 			// +k8s:validation:minItems=1
 			// +k8s:validation:uniqueItems
 			ArrayValue []string