FileTransferMixin

FileTransferMixin is a module that you can include in a library. It will support various mechanisms long-term, but for now is focused on SFTP and FTP servers.

It provides the following methods for now:

• sftp_send(key, remote_location, local_file_path)
• sftp_fetch(key, remote_path, local_path)
• sftp_move(key, original_remote_path, new_remote_path)
• sftp_block(key)
• ftp_send(key, remote_location, local_file_path)
• ftp_fetch(key, remote_path, local_path)
• ftp_move(key, original_remote_path, new_remote_path)
• ftp_block(key)

It expects an ENV variable named FILE_TRANSFER_MIXIN_CONFIG_PATH to be set. It expects a yml configuration file in FILE_TRANSFER_MIXIN_CONFIG_PATH that looks like the following:

:development:
  :sftp:
    :some_key:
      :server: 127.0.0.1
      :username: user
      :password: pass
  :ftp:
    :some_key:
      :server: 127.0.0.1
      :username: user
      :password: pass

:test: {}

:production: {}

Then in a class, you would deal with it thusly:

class SomeClass
  include FileTransferMixin

  # Some method that uploads a file via sftp
  def some_method
    sftp_send(:some_key, remote_path, local_path)
  end

  # Some method that fetches a file via sftp
  def fetch_method
    sftp_fetch(:some_key, remote_path, local_path)
  end

  # Some method that moves a file via sftp
  def move_method
    sftp_move(:some_key, original_remote_path, new_remote_path)
  end

  # Some method that otherwise uses Net::SFTP commands but still uses our config block
  def sftp_detailed_method
    sftp_block(:some_key) do |sftp|
      sftp.rename!('foo', 'bar')
    end
  end

  # Some method that uploads a file via ftp
  def some_method
    ftp_send(:some_key, remote_path, local_path)
  end

  # Some method that fetches a file via ftp
  def fetch_method
    ftp_fetch(:some_key, remote_path, local_path)
  end

  # Some method that moves a file via ftp
  def move_method
    ftp_move(:some_key, original_remote_path, new_remote_path)
  end

  # Some method that otherwise uses Net::FTP commands but still uses our config block
  def ftp_detailed_method
    ftp_block(:some_key) do |ftp|
      puts "foo's last modification time: #{ftp.mtime('foo')}"
    end
  end
end

Motivation

We have quite a few libraries that interact with remote SFTP and FTP servers, and inevitably they share massive swathes of code that should be unnecessary. This intends to be a mixin to make the easy things extremely easy.