Fix crash when parsing large configuration files (#969)

Signed-off-by: Kimmo Lehto <[email protected]>

Author: kke

pkg/manifest/reader.go

@@ -3,6 +3,7 @@ package manifest
 import (
 	"bufio"
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -12,6 +13,7 @@ import (
 	"time"
 
 	"gopkg.in/yaml.v2"
+	yamlutil "k8s.io/apimachinery/pkg/util/yaml"
 )
 
 // ResourceDefinition represents a single Kubernetes resource definition.
@@ -64,27 +66,6 @@ func (rd *ResourceDefinition) Unmarshal(obj any) error {
 	return nil
 }
 
-func yamlDocumentSplit(data []byte, atEOF bool) (advance int, token []byte, err error) {
-	if atEOF && len(data) == 0 {
-		return 0, nil, nil
-	}
-
-	// Look for the document separator
-	sepIndex := bytes.Index(data, []byte("\n---"))
-	if sepIndex >= 0 {
-		// Return everything up to the separator
-		return sepIndex + len("\n---"), data[:sepIndex], nil
-	}
-
-	// If at EOF, return the remaining data
-	if atEOF {
-		return len(data), data, nil
-	}
-
-	// Request more data
-	return 0, nil, nil
-}
-
 // Reader reads Kubernetes resource definitions from input streams.
 type Reader struct {
 	IgnoreErrors bool
@@ -100,14 +81,18 @@ func name(r io.Reader) string {
 
 // Parse parses Kubernetes resource definitions from the provided input stream. They are then available via the Resources() or GetResources(apiVersion, kind) methods.
 func (r *Reader) Parse(input io.Reader) error {
-	scanner := bufio.NewScanner(input)
-	scanner.Split(yamlDocumentSplit)
+	yamlReader := yamlutil.NewYAMLReader(bufio.NewReader(input))
 
-	for scanner.Scan() {
-		rawChunk := scanner.Bytes()
+	for {
+		rawChunk, err := yamlReader.Read()
+		if err != nil {
+			if errors.Is(err, io.EOF) {
+				break
+			}
+			return fmt.Errorf("error reading input: %w", err)
+		}
 
-		// Skip empty chunks
-		if len(rawChunk) == 0 {
+		if len(bytes.TrimSpace(rawChunk)) == 0 {
 			continue
 		}
 
@@ -131,10 +116,6 @@ func (r *Reader) Parse(input io.Reader) error {
 		r.manifests = append(r.manifests, rd)
 	}
 
-	if err := scanner.Err(); err != nil {
-		return fmt.Errorf("error reading input: %w", err)
-	}
-
 	return nil
 }
 

pkg/manifest/reader_test.go

@@ -1,6 +1,7 @@
 package manifest_test
 
 import (
+	"fmt"
 	"strings"
 	"testing"
 
@@ -149,3 +150,33 @@ metadata:
 	require.NoError(t, err, "GetResources should not return an error for Services")
 	assert.Len(t, services, 1, "Expected 1 Service to be returned")
 }
+
+func TestReader_ParseHandlesLargeManifest(t *testing.T) {
+	largeData := strings.Repeat("x", 70*1024)
+	manifestStr := fmt.Sprintf(`apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: big-config
+data:
+  payload: "%s"
+`, largeData)
+
+	r := &manifest.Reader{}
+	require.NoError(t, r.Parse(strings.NewReader(manifestStr)))
+	require.Equal(t, 1, r.Len(), "Expected a single manifest to be parsed")
+
+	resource := r.Resources()[0]
+	require.Equal(t, "ConfigMap", resource.Kind)
+	require.Equal(t, "v1", resource.APIVersion)
+	require.Equal(t, strings.TrimSpace(manifestStr), strings.TrimSpace(string(resource.Raw)))
+
+	var parsed struct {
+		APIVersion string            `yaml:"apiVersion"`
+		Kind       string            `yaml:"kind"`
+		Metadata   map[string]string `yaml:"metadata"`
+		Data       map[string]string `yaml:"data"`
+	}
+	require.NoError(t, resource.Unmarshal(&parsed))
+	require.Contains(t, parsed.Data, "payload")
+	require.Len(t, parsed.Data["payload"], len(largeData))
+}