docs: def ensure_secret():
      """Check if secret key to encryot sessions exists,
      generate it otherwise."""
      home_dir = os.environ['HOME']
      file_name = home_dir + "/.ipcamweb"
      if os.path.exists(file_name):
          with open(file_name, "r") as s_file:
              secret = s_file.readline()
      else:
          secret = os.urandom(24)
          with open(file_name, "w") as s_file:
              secret = s_file.write(secret+"\n")
      return secret