S3 images downloading instead of displaying when uploading with Golang - amazon-web-services

Question

I'm trying to upload an image to AWS S3. The images are saving in the bucket but when I click on them (their URL) they download instead of displaying. In the past this has been because the Content Type wasn't set to image/jpeg but I verified this time that it is.
Here's my code:
func UploadImageToS3(file os.File) error {
fi, err := file.Stat() // get FileInfo
if err != nil {
return errors.New("Couldn't get FileInfo")
}
size := fi.Size()
buffer := make([]byte, size)
file.Read(buffer)
tempFileName := "images/picturename.jpg" // key to save under
putObject := &s3.PutObjectInput{
Bucket: aws.String("mybucket"),
Key: aws.String(tempFileName),
ACL: aws.String("public-read"),
Body: bytes.NewReader(buffer),
ContentLength: aws.Int64(int64(size)),
// verified is properly getting image/jpeg
ContentType: aws.String(http.DetectContentType(buffer)),
}
_, err = AwsS3.PutObject(putObject)
if err != nil {
log.Fatal(err.Error())
return err
}
return nil
}
I also tried making my s3.PutObjectInput as
putObject := &s3.PutObjectInput{
Bucket: aws.String("mybucket"),
Key: aws.String(tempFileName),
ACL: aws.String("public-read"),
Body: bytes.NewReader(buffer),
ContentLength: aws.Int64(int64(size)),
ContentType: aws.String(http.DetectContentType(buffer)),
ContentDisposition: aws.String("attachment"),
ServerSideEncryption: aws.String("AES256"),
StorageClass: aws.String("INTELLIGENT_TIERING"),
}
What am I doing wrong here?

Answer 1

Figured it out.
Not totally sure why, but I needed to separate all the values.
var size int64 = fi.Size()
buffer := make([]byte, size)
file.Read(buffer)
fileBytes := bytes.NewReader(buffer)
fileType := http.DetectContentType(buffer)
path := "images/test.jpeg"
params := &s3.PutObjectInput{
Bucket: aws.String("mybucket"),
Key: aws.String(path),
Body: fileBytes,
ContentLength: aws.Int64(size),
ContentType: aws.String(fileType),
}
_, err = AwsS3.PutObject(params)
If anyone knows why this works and the previous code doesn't, please share.