stream 'multipart form data' to S3 bucket

stream-to-S3.go

func MultipartUploadHandler(c *gin.Context) {
	multipart, err := c.Request.MultipartReader()
	if err != nil {
		log.Fatalln("Failed to create MultipartReader", err)
	}

	for {
		mimePart, err := multipart.NextPart()
		if err == io.EOF {
			break
		}
		if err != nil {
			log.Printf("Error reading multipart section: %v", err)
			break
		}
		disposition, params, err := mime.ParseMediaType(mimePart.Header.Get("Content-Disposition"))
		if err != nil {
			log.Printf("Invalid Content-Disposition: %v", err)
			break
		}

		// S3 Upload Manager
		uploader := s3manager.NewUploader(session.New(&aws.Config{Region: aws.String("us-west-2")}))
		result, err := uploader.Upload(&s3manager.UploadInput{
			Body:   mimePart,
			Bucket: aws.String("yourbucket"),
			Key:    aws.String(params["filename"]),
			ContentType: aws.String(mimePart.Header.Get("Content-Type")),
			ACL: aws.String("public-read"),
		})
		if err != nil {
			log.Fatalln("Failed to upload to S3", err)
		}
		
		c.JSON(http.StatusOK, gin.H{
			"location": result.Location,
		})
	}
}