fix(pdfengines): read metadata better webhook error - fixes #1148

pkg/modules/pdfengines/routes.go

@@ -500,6 +500,11 @@ func readMetadataRoute(engine gotenberg.PdfEngine) api.Route {
 
 			err = c.JSON(http.StatusOK, res)
 			if err != nil {
+				if strings.Contains(err.Error(), "request method or response status code does not allow body") {
+					// High probability that the user is using the webhook
+					// feature. It does not make sense for this route.
+					return api.ErrNoOutputFile
+				}
 				return fmt.Errorf("return JSON response: %w", err)
 			}
 

pkg/modules/webhook/middleware.go

@@ -184,11 +184,21 @@ func webhookMiddleware(w *Webhook) api.Middleware {
 						// Call the next middleware in the chain.
 						err := next(c)
 						if err != nil {
+							if errors.Is(err, api.ErrNoOutputFile) {
+								errNoOutputFile := fmt.Errorf("%w - the webhook middleware cannot handle the result of this route", err)
+								handleAsyncError(api.WrapError(
+									errNoOutputFile,
+									api.NewSentinelHttpError(
+										http.StatusBadRequest,
+										"The webhook middleware can only work with multipart/form-data routes that results in output files",
+									),
+								))
+								return
+							}
 							// The process failed for whatever reason. Let's send the
 							// details to the webhook.
 							ctx.Log().Error(err.Error())
 							handleAsyncError(err)
-
 							return
 						}
 
@@ -197,7 +207,6 @@ func webhookMiddleware(w *Webhook) api.Middleware {
 						if err != nil {
 							ctx.Log().Error(fmt.Sprintf("build output file: %s", err))
 							handleAsyncError(err)
-
 							return
 						}
 
@@ -205,7 +214,6 @@ func webhookMiddleware(w *Webhook) api.Middleware {
 						if err != nil {
 							ctx.Log().Error(fmt.Sprintf("open output file: %s", err))
 							handleAsyncError(err)
-
 							return
 						}
 
@@ -221,7 +229,6 @@ func webhookMiddleware(w *Webhook) api.Middleware {
 						if err != nil {
 							ctx.Log().Error(fmt.Sprintf("read header of output file: %s", err))
 							handleAsyncError(err)
-
 							return
 						}
 
@@ -229,7 +236,6 @@ func webhookMiddleware(w *Webhook) api.Middleware {
 						if err != nil {
 							ctx.Log().Error(fmt.Sprintf("get stat from output file: %s", err))
 							handleAsyncError(err)
-
 							return
 						}
 
@@ -237,7 +243,6 @@ func webhookMiddleware(w *Webhook) api.Middleware {
 						if err != nil {
 							ctx.Log().Error(fmt.Sprintf("reset output file reader: %s", err))
 							handleAsyncError(err)
-
 							return
 						}