If s3fs cannot read file, it is possible that ACL has issue. One method is make object public.

Step-by-step guide

We use ncml-lambda as bucket name. The following is Python lambda code.

  1. s3 = boto3.resource('s3')

  2. s3.meta.client.upload_file(tmpname, 'ncml-lambda', oname)

  3. object_acl = s3.ObjectAcl('ncml-lambda', oname)

  4. result = object_acl.put(ACL='public-read')


This is not recommended if security matters.