fix(api): wait for modules readiness before starting server (#752)

pkg/modules/libreoffice/api/api.go

@@ -97,7 +97,7 @@ func (a *Api) Descriptor() gotenberg.ModuleDescriptor {
 
 			fs.Int64("libreoffice-restart-after", 10, "Number of conversions after which LibreOffice will automatically restart. Set to 0 to disable this feature")
 			fs.Bool("libreoffice-auto-start", false, "Automatically launch LibreOffice upon initialization if set to true; otherwise, LibreOffice will start at the time of the first conversion")
-			fs.Duration("libreoffice-start-timeout", time.Duration(10)*time.Second, "Maximum duration to wait for LibreOffice to start or restart")
+			fs.Duration("libreoffice-start-timeout", time.Duration(20)*time.Second, "Maximum duration to wait for LibreOffice to start or restart")
 
 			return fs
 		}(),
@@ -277,6 +277,34 @@ func (a *Api) Checks() ([]health.CheckerOption, error) {
 	}, nil
 }
 
+// Ready returns no error if the module is ready.
+func (a *Api) Ready() error {
+	if !a.autoStart {
+		return nil
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), a.args.startTimeout)
+	defer cancel()
+
+	ticker := time.NewTicker(time.Duration(100) * time.Millisecond)
+
+	for {
+		select {
+		case <-ctx.Done():
+			ticker.Stop()
+			return fmt.Errorf("context done while waiting for LibreOffice to be ready: %w", ctx.Err())
+		case <-ticker.C:
+			ok := a.libreOffice.Healthy(a.logger)
+			if ok {
+				ticker.Stop()
+				return nil
+			}
+
+			continue
+		}
+	}
+}
+
 // LibreOffice returns a [Uno] for interacting with LibreOffice.
 func (a *Api) LibreOffice() (Uno, error) {
 	return a, nil

pkg/modules/libreoffice/api/api_test.go

@@ -364,6 +364,61 @@ func TestApi_Checks(t *testing.T) {
 	}
 }
 
+func TestChromium_Ready(t *testing.T) {
+	for _, tc := range []struct {
+		scenario     string
+		autoStart    bool
+		startTimeout time.Duration
+		libreOffice  libreOffice
+		expectError  bool
+	}{
+		{
+			scenario:     "no auto-start",
+			autoStart:    false,
+			startTimeout: time.Duration(30) * time.Second,
+			libreOffice: &libreOfficeMock{ProcessMock: gotenberg.ProcessMock{HealthyMock: func(logger *zap.Logger) bool {
+				return false
+			}}},
+			expectError: false,
+		},
+		{
+			scenario:     "auto-start: context done",
+			autoStart:    true,
+			startTimeout: time.Duration(200) * time.Millisecond,
+			libreOffice: &libreOfficeMock{ProcessMock: gotenberg.ProcessMock{HealthyMock: func(logger *zap.Logger) bool {
+				return false
+			}}},
+			expectError: true,
+		},
+		{
+			scenario:     "auto-start success",
+			autoStart:    true,
+			startTimeout: time.Duration(30) * time.Second,
+			libreOffice: &libreOfficeMock{ProcessMock: gotenberg.ProcessMock{HealthyMock: func(logger *zap.Logger) bool {
+				return true
+			}}},
+			expectError: false,
+		},
+	} {
+		t.Run(tc.scenario, func(t *testing.T) {
+			a := new(Api)
+			a.autoStart = tc.autoStart
+			a.args = libreOfficeArguments{startTimeout: tc.startTimeout}
+			a.libreOffice = tc.libreOffice
+
+			err := a.Ready()
+
+			if !tc.expectError && err != nil {
+				t.Fatalf("expected no error but got: %v", err)
+			}
+
+			if tc.expectError && err == nil {
+				t.Fatal("expected error but got none")
+			}
+		})
+	}
+}
+
 func TestApi_LibreOffice(t *testing.T) {
 	a := new(Api)
 

pkg/modules/libreoffice/pdfengine/pdfengine.go

@@ -18,7 +18,7 @@ func init() {
 // LibreOfficePdfEngine interacts with the LibreOffice (Universal Network Objects) API
 // and implements the [gotenberg.PdfEngine] interface.
 type LibreOfficePdfEngine struct {
-	unoAPI api.Uno
+	unoApi api.Uno
 }
 
 // Descriptor returns a [LibreOfficePdfEngine]'s module descriptor.
@@ -36,12 +36,12 @@ func (engine *LibreOfficePdfEngine) Provision(ctx *gotenberg.Context) error {
 		return fmt.Errorf("get LibreOffice Uno provider: %w", err)
 	}
 
-	unoAPI, err := provider.(api.Provider).LibreOffice()
+	unoApi, err := provider.(api.Provider).LibreOffice()
 	if err != nil {
 		return fmt.Errorf("get LibreOffice Uno: %w", err)
 	}
 
-	engine.unoAPI = unoAPI
+	engine.unoApi = unoApi
 
 	return nil
 }
@@ -56,7 +56,7 @@ func (engine *LibreOfficePdfEngine) Merge(ctx context.Context, logger *zap.Logge
 // PDF format is requested, it returns a [gotenberg.ErrPdfFormatNotSupported]
 // error.
 func (engine *LibreOfficePdfEngine) Convert(ctx context.Context, logger *zap.Logger, formats gotenberg.PdfFormats, inputPath, outputPath string) error {
-	err := engine.unoAPI.Pdf(ctx, logger, inputPath, outputPath, api.Options{
+	err := engine.unoApi.Pdf(ctx, logger, inputPath, outputPath, api.Options{
 		PdfFormats: formats,
 	})
 

pkg/modules/libreoffice/pdfengine/pdfengine_test.go

@@ -153,7 +153,7 @@ func TestLibreOfficePdfEngine_Convert(t *testing.T) {
 		},
 	} {
 		t.Run(tc.scenario, func(t *testing.T) {
-			engine := &LibreOfficePdfEngine{unoAPI: tc.api}
+			engine := &LibreOfficePdfEngine{unoApi: tc.api}
 			err := engine.Convert(context.Background(), zap.NewNop(), gotenberg.PdfFormats{}, "", "")
 
 			if !tc.expectError && err != nil {