Should I delete uploaded files from the file system on my own?

Question

I have a rails app where the user can upload files. The files get uploaded to an external cloud service by a backgroud jobs. It's vital for my app that the files won't get stored in the file system after they've been uploaded. Not right away, in general -- they must not remain in the file system.

Should I delete them on my own? Or will get deleted automatically?

Also, debugging my app, I noticied this for an attachment params:

[2] pry(#<MyController>)> my_params.tempfile.path
"/var/folders/qr/0v5z71xn7x503ykyv1j6lkp00000gn/T/RackMultipart20181007-10937-3ntmgg.png"

That file gets stored not in "/tmp" but in "/var" and that means that it won't get deleted automatically, right?

Note that I'm not using paperclip for this task.

Answer 1

You are right the files won't get deleted automatically. You have to delete the file explicitly at some point in time.

Answer 2

It depends how you set it up. If you used Tempfile to save it then yes the files will be deleted when the object is garbage collected. If not then it probably won't be deleted.

If the files get stored on an external service it might be worth setting up ActiveStorage which allows you to directly upload to external storage providers without the file ever touching your server.