text: # From https://raw.githubusercontent.com/jupyter/docker-stacks/master/base-notebook/jupyter_notebook_config.py
  # Copyright (c) Jupyter Development Team.
  # Distributed under the terms of the Modified BSD License.
  
  from jupyter_core.paths import jupyter_data_dir
  import subprocess
  import os
  import errno
  import stat
  
  c = get_config()
  c.NotebookApp.ip = '0.0.0.0'
  c.NotebookApp.port = 8888
  c.NotebookApp.open_browser = False
  
  # https://github.com/jupyter/notebook/issues/3130
  c.FileContentsManager.delete_to_trash = False
  
  # Generate a self-signed certificate
  if 'GEN_CERT' in os.environ:
      dir_name = jupyter_data_dir()
      pem_file = os.path.join(dir_name, 'notebook.pem')
      try:
          os.makedirs(dir_name)
      except OSError as exc:  # Python >2.5
          if exc.errno == errno.EEXIST and os.path.isdir(dir_name):
              pass
          else:
              raise
  
      # Generate an openssl.cnf file to set the distinguished name
      cnf_file = os.path.join(os.getenv('CONDA_DIR', '/usr/lib'), 'ssl', 'openssl.cnf')
      if not os.path.isfile(cnf_file):
          with open(cnf_file, 'w') as fh:
              fh.write('''\
  [req]
  distinguished_name = req_distinguished_name
  [req_distinguished_name]
  ''')
  
      # Generate a certificate if one doesn't exist on disk
      subprocess.check_call(['openssl', 'req', '-new',
                             '-newkey', 'rsa:2048',
                             '-days', '365',
                             '-nodes', '-x509',
                             '-subj', '/C=XX/ST=XX/L=XX/O=generated/CN=generated',
                             '-keyout', pem_file,
                             '-out', pem_file])
      # Restrict access to the file
      os.chmod(pem_file, stat.S_IRUSR | stat.S_IWUSR)
      c.NotebookApp.certfile = pem_file
  
  # Change default umask for all subprocesses of the notebook server if set in
  # the environment
  if 'NB_UMASK' in os.environ:
      os.umask(int(os.environ['NB_UMASK'], 8))
  