utils.py

#!/usr/bin/env python3


# developed by Gabi Zapodeanu, TSA, GPO, Cisco Systems


# the utils module includes common utilized utility functions

import json
import os
import os.path
import re  # needed for regular expressions matching
import select
import socket  # needed for IPv4 validation
import sys
import urllib3
import subprocess  # needed for the ping function

from urllib3.exceptions import InsecureRequestWarning

urllib3.disable_warnings(InsecureRequestWarning)  # Disable insecure https warnings


def pprint(json_data):
    """
    Pretty print JSON formatted data
    :param json_data:
    :return:
    """

    print(json.dumps(json_data, indent=4, separators=(' , ', ' : ')))


def get_input_ip():
    """
    This function will ask the user to input the IP address. The format of the IP address is not validated
    The function will return the IP address
    :return: the IP address
    """

    ip_address = input('Input the IP address to be validated, (or q to exit) ?  ')
    return ip_address


def get_input_mac():
    """
    This function will ask the user to input the IP address. The format of the IP address is not validated
    The function will return the IP address
    :return: the IP address
    """

    mac_address = input('Input the MAC address to be validated, (or q to exit) ?  ')
    return mac_address


def get_input_timeout(message, wait_time):
    """
    This function will ask the user to input the value requested in the {message}, in the time specified {time}
    :param message: message to provide the user information on what is required
    :param wait_time: time limit for the user input
    :return: user input as string
    """

    print(message + ' in ' + str(wait_time) + ' seconds')
    i, o, e = select.select([sys.stdin], [], [], wait_time)
    if i:
        input_value = sys.stdin.readline().strip()
        print('User input: ', input_value)
    else:
        input_value = None
        print('No user input in ', wait_time, ' seconds')
    return input_value


def validate_ipv4_address(ip_address):
    """
    This function will validate if the provided string is a valid IPv4 address
    :param ip_address: string with the IPv4 address
    :return: true/false
    """
    try:
        socket.inet_aton(ip_address)
        return True
    except:
        return False


def identify_ipv4_address(configuration):
    """
    This function will return a list of all IPv4 addresses found in the string {configuration}.
    It will return only the IPv4 addresses found in the {ip address a.b.c.d command}
    :param configuration: string with the configuration
    :return: list of IPv4 addresses
    """
    ipv4_list = []
    pattern = re.compile('^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$')
    split_lines = configuration.split('\n')  # split configuration file in individual commands'
    for line in split_lines:
        if 'ip address' in line:  # check if command includes the string 'ip address'
            split_config = line.split(' ')  # split the command in words
            try:
                split_config.remove('')  # remove the first ' ' if existing in the command
            except:
                pass
            line_begins = split_config[0:3]  # select the three items in the list
            for word in line_begins:
                check_ip = pattern.match(word)  # match each word with the pattern from regex
                if check_ip:
                    if validate_ipv4_address(word):  # validate if the octets are valid IP addresses
                        ipv4_list.append(word)
    return ipv4_list


def ping_return(hostname):
    """
    Use the ping utility to attempt to reach the host. We send 5 packets
    ('-c 5') and wait 250 milliseconds ('-W 250') for a response. The function
    returns the return code from the ping utility.
    It will also save the output to the file {ping_hostname}
    :param hostname: hostname or the IPv4 address of the device to ping
    """
    ret_code = subprocess.call(['ping', '-c', '5', '-W', '250', hostname], stdout=open('ping_' + hostname, 'w'))
    if ret_code == 0:
        return_code = 'Success'
    elif ret_code == 2:
        return_code = 'Failed'
    else:
        return_code = 'Unknown'
    return return_code