如何在rails中链接单个私有S3文件以进行下载

Question

I want to provide a link for users to download a non-public file from Amazon S3 in my rails app. This is not a user-uploaded file, just a single file that I've uploaded that anyone who's logged in should be able to download.

I'm getting lost in S3 documentation/parameters/syntax. Like hours lost. Here's the Amazon url to the non-public file: https://s3-us-west-1.amazonaws.com/physicianneedtool/static/Historical_Payer_Profile.xlsx . The S3_BUCKET, S3_KEY, S3_SECRET_KEY and S3_REGION variables already work with my carrierwave setup in the app, so I know they're good.

My current non-working code:

s3 = Aws::S3::Resource.new(region: ENV["S3_REGION"], 
                           access_key_id: ENV["S3_KEY"], 
                           secret_access_key: ENV["S3_SECRET_KEY"])

@file_url = s3.bucket(ENV["S3_BUCKET"])
              .object('Historical_Payer_Profile.xlsx')
              .get(response_target: 'static/Historical_Payer_Profile.xlsx')

The error I get is Aws::S3::Errors::NoSuchKey. In rails console, I found that s3.bucket(ENV["S3_BUCKET"]).object('Historical_Payer_Profile.xlsx') returns a seemingly valid S3 object, so it looks like the error is caused by the .get call at the end. What am I doing wrong there? The path specified for response_target is the exact path I get from the copy path button in the S3 console.

Answer 1

You can use Aws::S3::Presigner , it allows you to create presigned URLs to share/download private files, and you can make this url expire after some time.

presigner = Aws::S3::Presigner.new
presigner.presigned_url(
  :get_object,
  bucket: ENV['S3_BUCKET'],
  key: ENV['S3_KEY'],
  expires_in: 1.day.to_i
).to_s