How do I copy a file onto a separate server using Net::FTP?

I'm building a Rails app which creates a bookmarklet file for each user upon sign-up. I'd like to save that file onto a remote server, so I'm trying Ruby's Net::FTP, based on "Rails upload file to ftp server".

I tried this code:

  require 'net/ftp'

  FileUtils.cp('public/ext/files/script.js', 'public/ext/bookmarklets/'+resource.authentication_token )
  file = File.open('public/ext/bookmarklets/'+resource.authentication_token, 'a') {|f| f.puts("cb_bookmarklet.init('"+resource.username+"', '"+resource.authentication_token+"', '"+resource.id.to_s+"');$('<link>', {href: '//***.com/bookmarklet/cb.css',rel: 'stylesheet',type: 'text/css'}).appendTo('head');});"); return f }
  ftp = Net::FTP.new('www.***.com')
  ftp.passive = true
  ftp.login(user = '***', psswd = '***')
  ftp.storbinary("STOR " + file.original_filename, StringIO.new(file.read), Net::FTP::DEFAULT_BLOCKSIZE)
  ftp.quit()

But I'm getting an error that the file variable is nil. I may be doing several things wrong here. I'm pretty new to Ruby and Rails, so any help is welcome.

Solution

The block form of File.open does not return the file handle (and even if it did, it would be closed at that point). Perhaps change your code to roughly:

require '…'
FileUtils.cp …
File.open('…','a') do |file|
  ftp = …
  ftp.storbinary("STOR #{file.original_filename}", StringIO.new(file.read))
  ftp.quit
end

Alternatively:

require '…'
FileUtils.cp …
filename = '…'
contents = IO.read(filename)
ftp = …
ftp.storbinary("STOR #{filename}", StringIO.new(contents))
ftp.quit