After doing a big research, I’ve not found any guide to upload images to S3 with private ACL.
I’m experiencing a weird behavior where the backups work but not uploadimg of images.
I narrowed the issue down to a problem with ACL of the bucket (I proved that the problem is the ACL since I’m able to upload file using the sdk without specifing the ACL flag). In some cases the “block access to public” permission are set at account level and not bucket level so deactivating the checkbox in the bucket config won’t work.
I got the same issue, too. Backup upload works but image upload shows “The bucket does not allow ACLs”
And it fixed by modifying one permission in IAM and two settings in bucket
First I changed the guide about IAM permission from “s3:HeadBucket” to “s3:ListBucket” because Amazon said HeadBucket is not a valid permission
Then the most important part, enable ACLs, it’s called Edit Object Ownership in permission tab, with ACLs enabled and set to object writer, everything just fine now