simplified_openvpn_helper.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# pylint: disable=R0904

"""File that contains SimplifiedOpenvpnHelper class."""

import os
import socket
import inspect
import hashlib
from requests import get


class SimplifiedOpenvpnHelper:
    """Class that contains shareable helper methods."""

    @staticmethod
    def current_method():
        """Returns name of the current method."""
        return inspect.stack()[1][3]

    @staticmethod
    def read_file_as_value(filename, verbose=False):
        """Reads contents of the file and returns it."""
        if not os.path.isfile(filename):
            if verbose:
                print("> File that you tried to read as value doesn't exist.")
            return None

        value = None
        with open(filename) as content:
            value = content.read().rstrip()
        return value

    @staticmethod
    def create_directory(value, mode=0o700):
        """Creates new directory on filesystem."""
        if not os.path.exists(value):
            os.makedirs(value, mode)

    @staticmethod
    def sanitize_path(path):
        """Makes sure that path are ending with forward slash."""
        if os.path.isfile(path):
            if path.endswith('/'):
                path = path.rstrip('/')
        elif os.path.isdir(path):
            if not path.endswith('/'):
                path = path + '/'

        return path

    @staticmethod
    def is_valid_ipv4(ipv4):
        """Check if IP is valid IPv4 address."""
        if isinstance(ipv4, str) and len(ipv4.strip()) > 6:
            return True
        return False

    @staticmethod
    def is_valid_hostname(hostname):
        """Checks if specified hostname matches rules and returns boolean."""
        if len(hostname) > 255 or len(hostname) < 1:
            return False
        return True

    @staticmethod
    def fetch_hostname_by_system():
        """Fetches Fully Qualified Domain Name from system."""
        return socket.getfqdn()

    @staticmethod
    def fetch_hostname_by_reverse_dns(ipv4=None):
        """Tries to fetch hostname by reverse DNS lookup and returns it if possible."""
        if ipv4 is None:
            ipv4 = SimplifiedOpenvpnHelper.fetch_external_ipv4()
        if ipv4:
            return socket.gethostbyaddr(ipv4)
        return None

    @staticmethod
    def fetch_external_ipv4():
        """Fetches and returns external IPv4 address."""
        ipv4 = get('http://api.ipify.org').text
        if ipv4:
            return ipv4.strip()
        return None

    @staticmethod
    def generate_share_hash(slug, sovpn_share_salt=''):
        """Calculates and return SOVPN share hash for specified slug."""
        feed = (sovpn_share_salt + slug).encode('utf-8')
        share_hash = hashlib.sha1(feed).hexdigest()
        return share_hash