Question

I’m sending the file file.txt from my Rails controller using send_file, and then delete the folder containing it.

send_file("#{Rails.root}/public/folder/file.txt")
FileUtils.remove_dir "#{Rails.root}/public/folder", true

When I did this, file.txt was sent and deleted. However, folder was not deleted. But if I remove the send_file line, then folder will be deleted.

How do I make it delete folder?

EDIT: Interestingly, I found that inside folder there is a hidden file called .__afs2B0C, probably preventing the deletion. I have no idea how this file is created! The file stays for only around 15 minutes before disappearing.

EDIT2: I’ve tried inspecting the content of the temp file with vi, but it’s unreadable gibberish. When I removed only the send_file line, the folder was correctly deleted. When I removed only the FileUtils.remove_dir line, the folder contains no temp file.

Answer 1

Are you sure the send_file is not still sending the file when you are removing the dir, it may be asynchronous if it uses X-SendFile? That would cause an error when trying to remove the dir.

So you should probably be queuing this delete action, or doing it with a sweeper later, rather than trying to do it straight after sending the file to streaming.

I’m not completely clear on which file you are sending, so it would be useful to include an actual example of file path, and file type, and how it is created in your question.

Possible help with debugging:

Log in and monitor the folder while you perform the following actions:

• Write out a very large file (> 60MB say), and check there is no invisible file created during your file creation process – I’m not clear on which file you are actually sending
• Set up a large file transfer on a slow connection, and watch for the creation and possibly growing of this file (it might be related to compressing the file served on the fly for example).

Given that sendfile may still be sending (for large files) via the web server (x-send-file is now default) when you try to delete, I’d try looking into delayed solutions.

Possible solutions:

• Use send_data rather than send_file (if files are small)
• Schedule the deletion of the folder for later with something like delayed_job
• Set up a sweeper which removes the folders at the end of each day