The final module

With all of our functions in place, the final module will look like this:

'''
The backend for serving files from an SFTP account.

To enable, add ``sftp`` to the :conf_master:`fileserver_backend` option in the
Master config file.

.. code-block:: yaml

    fileserver_backend:
      - sftp

Each environment is configured as a directory inside the SFTP account. The name
of the directory must match the name of the environment.

.. code-block:: yaml

    sftpfs_host: sftp.example.com
    sftpfs_port: 22
    sftpfs_username: larry
    sftpfs_password: 123pass
    sftpfs_root: /srv/sftp/salt/
'''
import os
import os.path
import logging
import time

try:
    import fcntl
    HAS_FCNTL = True
except ImportError:
    # fcntl is not available on windows
    HAS_FCNTL = False

import salt.fileserver
import salt.utils
import salt.syspaths

try:
    import paramiko
    from paramiko import AuthenticationException
    HAS_LIBS = True
except ImportError:
    HAS_LIBS = False

__virtualname__...