fix(repo): write repositories.yaml atomically using AtomicWriteFile

File.WriteFile used os.WriteFile, which truncates the destination file before writing data. If the write fails (due to quota, full disk, etc.) or the process is interrupted, repositories.yaml is left empty.

Use fileutil.AtomicWriteFile to ensure updates to repositories.yaml are performed atomically via temporary file and rename, matching the behavior of index.go and chartrepo.go.

Signed-off-by: jdymitarai <o10040115@gmail.com>

pkg/repo/v1/repo.go

@@ -17,12 +17,15 @@ limitations under the License.
 package repo
 
 import (
+	"bytes"
 	"fmt"
 	"os"
 	"path/filepath"
 	"time"
 
 	"sigs.k8s.io/yaml"
+
+	"helm.sh/helm/v4/internal/fileutil"
 )
 
 // File represents the repositories.yaml file
@@ -121,5 +124,5 @@ func (r *File) WriteFile(path string, perm os.FileMode) error {
 	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
 		return err
 	}
-	return os.WriteFile(path, data, perm)
+	return fileutil.AtomicWriteFile(path, bytes.NewReader(data), perm)
 }

pkg/repo/v1/repo_test.go

@@ -18,6 +18,7 @@ package repo
 
 import (
 	"os"
+	"path/filepath"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -168,6 +169,7 @@ func TestWriteFile(t *testing.T) {
 
 	file, err := os.CreateTemp(t.TempDir(), "helm-repo")
 	require.NoErrorf(t, err, "failed to create test-file")
+	require.NoError(t, file.Close())
 	defer os.Remove(file.Name())
 	require.NoErrorf(t, sampleRepository.WriteFile(file.Name(), 0o600), "failed to write file")
 
@@ -207,3 +209,32 @@ func TestRemoveRepositoryInvalidEntries(t *testing.T) {
 	assert.Truef(t, sampleRepository.Remove(removeRepository), "expected repository %s not found", removeRepository)
 	assert.Falsef(t, sampleRepository.Has(removeRepository), "repository %s not deleted", removeRepository)
 }
+
+func TestWriteFile_Atomic(t *testing.T) {
+	dir := t.TempDir()
+	filePath := filepath.Join(dir, "repositories.yaml")
+
+	initialRepo := NewFile()
+	initialRepo.Add(&Entry{
+		Name: "initial",
+		URL:  "https://example.com/initial",
+	})
+	require.NoError(t, initialRepo.WriteFile(filePath, 0o644))
+
+	initialData, err := os.ReadFile(filePath)
+	require.NoError(t, err)
+	require.NotEmpty(t, initialData)
+
+	updatedRepo := NewFile()
+	updatedRepo.Add(&Entry{
+		Name: "updated",
+		URL:  "https://example.com/updated",
+	})
+	require.NoError(t, updatedRepo.WriteFile(filePath, 0o644))
+
+	loaded, err := LoadFile(filePath)
+	require.NoError(t, err)
+	assert.False(t, loaded.Has("initial"))
+	assert.True(t, loaded.Has("updated"))
+}
+