ssh_connection.py

import paramiko
import datetime
import os.path
import time
import sys
import re

#Checking username/password file
#Prompting user for input - USERNAME/PASSWORD FILE
user_file = input("\n# Enter username/password file path and name (e.g. D:\MyApps\filename.txt): ")

#Verifying the validity of the USERNAME/PASSWORD file
if os.path.isfile(user_file) == True:
    print("\n* Username/password file is valid :)\n")
else:
    print("\n* File {} does not exist :( Please check and try again.\n)".format(user_file))
    sys.exit()
    

#Checking commands file
#Prompting user for input - COMMAND FILE
cmd_file = input("\n# Enter command file path and name (e.g. D:\MyApps\filename.txt): ")
if os.path.isfile(cmd_file) == True:
    print("\n* Command file is valid :)\n")
else:
    print("\n* File {} does not exist :( Please check and try again.\n)".format(cmd_file))
    sys.exit()
    

#Open SSHv2 connection to the device
def ssh_connection(ip):
    
    global user_file
    global cmd_file
    
    #Creating SSH CONNECTION
    try:
        #Define SSH parameters
        selected_user_file = open(user_file, 'r')
        
        #Starting from the beginning of the file
        selected_user_file.seek(0)
        
        #Reading the username from the file
        username = selected_user_file.readlines()[0].split(',')[0].rstrip("\n")
        
        #Starting from the beginning of the file
        selected_user_file.seek(0)
        
        #Reading the password from the file
        password = selected_user_file.readlines()[0].split(',')[1].rstrip("\n")
        
        #Logging into the device
        session = paramiko.SSHClient()
        
        #For testing purposes, this allows auto-accepting unknown host keys
        #Do not use in production! The default would be RejectPolicy
        session.set_missing_host_key_policy(paramiko.AutoAddPolicy())
        
        #Connect to the device using username and password
        session.connect(ip.rstrip("\n"), username = username, password = password)
        
        #Start an interactive shell session on the router
        connection = session.invoke_shell()
        
        #Setting terminal length for entire output - disable pagination
        connection.send("enable\n")
        connection.send("terminal length 0\n")
        time.sleep(1)
        
        #Entering global config mode
        connection.send("\n")
        connection.send("configure terminal\n")
        time.sleep(1)
        
        #Open user selected file for reading
        selected_cmd_file = open(cmd_file, 'r')
        
        #Starting from the beginning of the file
        selected_cmd_file.seek(0)
        
        #Writing each line in the file to the device
        for each_line in selected_cmd_file.readlines():
            connection.send(each_line + '\n')
            time.sleep(2)
        
        #Closing the user file
        selected_user_file.close()
        
        
        #Closing the cmd file
        selected_cmd_file.close()
        
        #checking command output for IOS syntax errors
        router_output = connection.recv(65535)
        
        if re.search(b"% Invalid input", router_output):
            print("*There was atleast one IOS syntax error on device {} :(".format(ip))
            
        else:
            print("\nDONE for device {}. Data sent to the file at {}.\n".format(ip, str(datetime.datetime.now())))
            
        #Test for reading command output
        #print(str(router_output) + "\n")
        
        #Searching for the CPU utilization value within the output of "show processes top once"
        cpu = re.search(b"%Cpu\(s\):(\s)+(.+?)(\s)+us,", router_output)
        
        #Extracting the second group, which matches the actual value of the CPU utilization and decoding the bytes object to produce a string (encoded to the popular UTF-8 format)w
        utilization = cpu.group(2).decode("utf-8")
        
        #Printing the CPU utilization value to the screen
        #print(utilization)
        
        #Opening the CPU utilization text file and appending the results
        with open(".\\cpu.txt", "a") as f:
            #f.write("{}, {}\n".format(str(datetime.datetime.now()), utilization))
            f.write(utilization + "\n")
        
        #Closing the connection
        session.close()
    
    except paramiko.AuthenticationException:
        print("* Invalid username or password : ( \n* Please check the username/password file used or the device configuration.")
        print("* Closing program... Bye!")