Using S3 Presigned-URL for upload a file that will then have public-read access

Question

I am using Ruby on Rails and AWS gem. I can get pre-signed URL for upload and download. But when I get the URL there is no file, and so setting acl to \'public-read\' on the

Answer 1

You have two options:

• Set the ACL on the object to 'public-read' when you PUT the object. This allows you to use the public url without a signature to GET the object.
• Let the ACL on the object default to private and provide pre-signed GET urls for users. These expire, so you have to generate new URLs as needed. A pre-signed URL allows someone to send GET request to the object without credentials themselves.

Upload a public object and generate a public url:

require 'aws-sdk'

s3 = Aws::S3::Resource.new
s3.bucket('bucket-name').object('key').upload_file('/path/to/file', acl:'public-read')
s3.public_url
#=> "https://bucket-name.s3.amazonaws.com/key"

Upload a private object and generate a GET url that is good for 1-hour:

s3 = Aws::S3::Resource.new
s3.bucket('bucket-name').object('key').upload_file('/path/to/file')
s3.presigned_url(:get, expires_in: 3600)
#=> "https://bucket-name.s3.amazonaws.com/key?X-Amz-Algorithm=AWS4-HMAC-SHA256&..."