feat(libreoffice): retry on core dumped (#930)

pkg/modules/libreoffice/api/api.go

@@ -28,6 +28,11 @@ var (
 	// ErrMalformedPageRanges happens if the page ranges option cannot be
 	// interpreted by LibreOffice.
 	ErrMalformedPageRanges = errors.New("page ranges are malformed")
+
+	// ErrCoreDumped happens randomly; sometime a conversion will work as
+	// expected, and some other time the same conversion will fail.
+	// See https://github.com/gotenberg/gotenberg/issues/639.
+	ErrCoreDumped = errors.New("core dumped")
 )
 
 // Api is a module which provides a [Uno] to interact with LibreOffice.
@@ -365,9 +370,20 @@ func (a *Api) LibreOffice() (Uno, error) {
 
 // Pdf converts a document to PDF.
 func (a *Api) Pdf(ctx context.Context, logger *zap.Logger, inputPath, outputPath string, options Options) error {
-	return a.supervisor.Run(ctx, logger, func() error {
+	err := a.supervisor.Run(ctx, logger, func() error {
 		return a.libreOffice.pdf(ctx, logger, inputPath, outputPath, options)
 	})
+
+	if err == nil {
+		return nil
+	}
+
+	// See https://github.com/gotenberg/gotenberg/issues/639.
+	if errors.Is(err, ErrCoreDumped) {
+		return a.Pdf(ctx, logger, inputPath, outputPath, options)
+	}
+
+	return fmt.Errorf("supervisor run task: %w", err)
 }
 
 // Extensions returns the file extensions available for conversions.

pkg/modules/libreoffice/api/api_test.go

@@ -433,6 +433,13 @@ func TestApi_Pdf(t *testing.T) {
 			}},
 			expectError: true,
 		},
+		{
+			scenario: "ErrCoreDumped",
+			libreOffice: &libreOfficeMock{pdfMock: func(ctx context.Context, logger *zap.Logger, input, outputPath string, options Options) error {
+				return ErrCoreDumped
+			}},
+			expectError: false,
+		},
 	} {
 		t.Run(tc.scenario, func(t *testing.T) {
 			a := new(Api)

pkg/modules/libreoffice/api/libreoffice.go

@@ -8,6 +8,7 @@ import (
 	"net"
 	"os"
 	"path/filepath"
+	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -348,6 +349,12 @@ func (p *libreOfficeProcess) pdf(ctx context.Context, logger *zap.Logger, inputP
 		return ErrMalformedPageRanges
 	}
 
+	// We may want to retry in case of a core dumped event.
+	// See https://github.com/gotenberg/gotenberg/issues/639.
+	if strings.Contains(err.Error(), "core dumped") {
+		return ErrCoreDumped
+	}
+
 	// Possible errors:
 	// 1. LibreOffice failed for some reason.
 	// 2. Context done.

pkg/modules/libreoffice/api/mocks.go

@@ -2,6 +2,7 @@ package api
 
 import (
 	"context"
+	"errors"
 
 	"go.uber.org/zap"
 
@@ -33,12 +34,21 @@ func (provider *ProviderMock) LibreOffice() (Uno, error) {
 
 // libreOfficeMock is a mock for the [libreOffice] interface.
 type libreOfficeMock struct {
+	errCoreDumpedCount int
+
 	gotenberg.ProcessMock
 	pdfMock func(ctx context.Context, logger *zap.Logger, inputPath, outputPath string, options Options) error
 }
 
 func (b *libreOfficeMock) pdf(ctx context.Context, logger *zap.Logger, inputPath, outputPath string, options Options) error {
-	return b.pdfMock(ctx, logger, inputPath, outputPath, options)
+	err := b.pdfMock(ctx, logger, inputPath, outputPath, options)
+	if errors.Is(err, ErrCoreDumped) {
+		b.errCoreDumpedCount += 1
+	}
+	if b.errCoreDumpedCount > 1 {
+		return nil
+	}
+	return err
 }
 
 // Interface guards.

pkg/modules/libreoffice/api/mocks_test.go

@@ -42,14 +42,53 @@ func TestProviderMock(t *testing.T) {
 }
 
 func TestLibreOfficeMock(t *testing.T) {
-	mock := &libreOfficeMock{
-		pdfMock: func(ctx context.Context, logger *zap.Logger, inputPath, outputPath string, options Options) error {
-			return nil
+	for _, tc := range []struct {
+		scenario    string
+		mock        *libreOfficeMock
+		expectError bool
+	}{
+		{
+			scenario: "success",
+			mock: &libreOfficeMock{
+				pdfMock: func(ctx context.Context, logger *zap.Logger, input, outputPath string, options Options) error {
+					return nil
+				},
+			},
+			expectError: false,
 		},
-	}
+		{
+			scenario: "ErrCoreDumped (first call)",
+			mock: &libreOfficeMock{
+				pdfMock: func(ctx context.Context, logger *zap.Logger, input, outputPath string, options Options) error {
+					return ErrCoreDumped
+				},
+			},
+			expectError: true,
+		},
+		{
+			scenario: "ErrCoreDumped (second call)",
+			mock: func() *libreOfficeMock {
+				m := &libreOfficeMock{
+					pdfMock: func(ctx context.Context, logger *zap.Logger, input, outputPath string, options Options) error {
+						return ErrCoreDumped
+					},
+				}
+				m.pdf(context.Background(), zap.NewNop(), "", "", Options{})
+				return m
+			}(),
+			expectError: false,
+		},
+	} {
+		t.Run(tc.scenario, func(t *testing.T) {
+			err := tc.mock.pdf(context.Background(), zap.NewNop(), "", "", Options{})
 
-	err := mock.pdf(context.Background(), zap.NewNop(), "", "", Options{})
-	if err != nil {
-		t.Errorf("expected no error from libreOfficeMock.pdf, but got: %v", err)
+			if !tc.expectError && err != nil {
+				t.Fatalf("expected no error from libreOfficeMock.pdf but got: %v", err)
+			}
+
+			if tc.expectError && err == nil {
+				t.Fatal("expected error from libreOfficeMock.pdf but got none")
+			}
+		})
 	}
 }