new_contents: # -*- coding: utf-8 -*-\
  '''
      unit.config_test
      ~~~~~~~~~~~~~~~~
  
      Configuration related unit testing
  
      :codeauthor: :email:`Pedro Algarvio (pedro@algarvio.me)`
      :copyright: © 2013 by the SaltStack Team, see AUTHORS for more details.
      :license: Apache 2.0, see LICENSE for more details.
  '''
  
  # Import python libs
  import os
  import shutil
  import tempfile
  
  # Import salt libs
  import salt.utils
  import salt.version
  
  # Import salt testing libs
  from salttesting import TestCase
  from salttesting.helpers import ensure_in_syspath
  ensure_in_syspath('../')
  
  # Import salt cloud libs
  from saltcloud import config as cloudconfig
  
  
  class CloudConfigTestCase(TestCase):
  
      def test_load_cloud_config_from_environ_var(self):
          if salt.version.__version_info__ < (0, 16, 0):
              self.skipTest(
                  'This test will always fail in salt >= 0.16.0 is not available'
              )
  
          original_environ = os.environ.copy()
  
          tempdir = tempfile.mkdtemp()
          try:
              env_root_dir = os.path.join(tempdir, 'foo', 'env')
              os.makedirs(env_root_dir)
              env_fpath = os.path.join(env_root_dir, 'config-env')
  
              salt.utils.fopen(env_fpath, 'w').write(
                  'root_dir: {0}\n'
                  'log_file: {1}\n'.format(env_root_dir, env_fpath)
              )
  
              os.environ['SALT_CLOUD_CONFIG'] = env_fpath
              # Should load from env variable, not the default configuration file
              config = cloudconfig.cloud_config('/etc/salt/cloud')
              self.assertEqual(config['log_file'], env_fpath)
              os.environ.clear()
              os.environ.update(original_environ)
  
              root_dir = os.path.join(tempdir, 'foo', 'bar')
              os.makedirs(root_dir)
              fpath = os.path.join(root_dir, 'config')
              salt.utils.fopen(fpath, 'w').write(
                  'root_dir: {0}\n'
                  'log_file: {1}\n'.format(root_dir, fpath)
              )
              # Let's set the environment variable, yet, since the configuration
              # file path is not the default one, ie, the user has passed an
              # alternative configuration file form the CLI parser, the
              # environment variable will be ignored.
              os.environ['SALT_CLOUD_CONFIG'] = env_fpath
              config = cloudconfig.cloud_config(fpath)
              self.assertEqual(config['log_file'], fpath)
              os.environ.clear()
              os.environ.update(original_environ)
  
          finally:
              if os.path.isdir(tempdir):
                  shutil.rmtree(tempdir)
  
  
  if __name__ == '__main__':
      from salttesting.parser import run_testcase
      run_testcase(CloudConfigTestCase)
  
subject: Add a test case to test loading config from an environment variable.