allow thumbnail.png to not exist

main.go

@@ -217,15 +217,17 @@ func main() {
 	}
 
 	// scan for thumbnail
+	var thumbnail *yt.Thumbnail
 	thumbnailPath, thumbnailSizeBytes, err := scanner.ScanThumbnail(directory)
 	if err != nil {
 		log.Fatalf("Failed to fetch thumbnail: %v", err)
 		os.Exit(1)
-	}
+	} else {
-	thumbnail := &yt.Thumbnail{
+		thumbnail = &yt.Thumbnail{
 			Filepath: thumbnailPath,
 			SizeBytes: thumbnailSizeBytes,
 		}
+	}
 
 	// build video template for upload
 	video, err := yt.BuildVideo(metadata)

scanner/scanner.go

@@ -2,6 +2,7 @@ package scanner
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"os"
 	"path"
@@ -65,6 +66,9 @@ func ScanThumbnail(directory string) (string, int64, error) {
 	thumbnailPath := path.Join(directory, "thumbnail.png")
 	stat, err := os.Stat(thumbnailPath)
 	if err != nil {
+		if os.IsNotExist(err) {
+			return "", 0, err
+		}
 		return "", 0, err
 	}
 	if stat.IsDir() {

youtube/youtube.go

@@ -285,14 +285,15 @@ func UploadVideo(
 		return nil, err
 	}
 
+	if thumbnail != nil {
 		// upload thumbnail
 
 		thumbnailService := youtube.NewThumbnailsService(service)
 		thumbnailSetCall := thumbnailService.Set(ytVideo.Id)
 		thumbnailFile, err := os.Open(thumbnail.Filepath)
 		if err != nil {
-		log.Fatalf("Failed to open thumbnail: %v\n", err)
+			log.Printf("Failed to open thumbnail: %v\n", err)
-		return nil, err
+			return ytVideo, err
 		}
 		thumbnailSetCall.Media(thumbnailFile)
 
@@ -307,6 +308,7 @@ func UploadVideo(
 		if err != nil {
 			log.Printf("Failed to upload thumbnail: %v\n", err)
 		}
+	}
 
 	return ytVideo, err
 }