We Keep Coding

How to Handel exception during Mysql connection

I m trying to connect to a mysql database. if server is not responding, my application crashes. I am using try, except but looks like two exceptions are raising and "try: except" could not handle it. can some one figure it out where is the problem. below is my code:-
def check_server(server_address):
con = mysql.connector.connect(host='{}'.format(server_address),
database='domicile_reports',
user='xyz',
password='xyz')
try:
if con.is_connected():
print('{} Connected'.format(server_address))
con.close()
except Exception as e:
print("Can not connect to db. {} Occured".format(e))
check_server('25.13.253.67')
Error displayed on terminal:-
Traceback (most recent call last):
File "C:\Users\Hamid Shah\AppData\Roaming\Python\Python310\site-packages\mysql\connector
network.py", line 574, in open_connection
self.sock.connect(sockaddr)
TimeoutError: [WinError 10060] A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "f:\Docs\OneDrive\Python Projects\CFC App\splash_screen_gui.py", line 151, in
obj = splashscreen()
File "f:\Docs\OneDrive\Python Projects\CFC App\splash_screen_gui.py", line 51, in init
self.check_server(self.server_2)
File "f:\Docs\OneDrive\Python Projects\CFC App\splash_screen_gui.py", line 80, in check_server
con = mysql.connector.connect(host='{}'.format(server_address),
File "C:\Users\Hamid Shah\AppData\Roaming\Python\Python310\site-packages\mysql\connector_init_.py", line 273, in connect
return MySQLConnection(*args, **kwargs)
File "C:\Users\Hamid Shah\AppData\Roaming\Python\Python310\site-packages\mysql\connector\connection.py", line 116, in init
self.connect(**kwargs)
File "C:\Users\Hamid Shah\AppData\Roaming\Python\Python310\site-packages\mysql\connector\abstracts.py", line 1052, in connect
self._open_connection()
File "C:\Users\Hamid Shah\AppData\Roaming\Python\Python310\site-packages\mysql\connector\connection.py", line 494, in _open_connection
self._socket.open_connection()
File "C:\Users\Hamid Shah\AppData\Roaming\Python\Python310\site-packages\mysql\connector\network.py", line 576, in open_connection
raise errors.InterfaceError(
mysql.connector.errors.InterfaceError: 2003: Can't connect to MySQL server on '25.13.253.67:3306' (10060 A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to
respond)

You need to put the connect() call inside the try: except block. You can also use a context manager to properly close the connection, example:
import mysql.connector
from mysql.connector.errors import Error
def check_server(server_address):
try:
with mysql.connector.connect(
host=server_address,
database="domicile_reports",
user="xyz",
password="xyz",
) as cnx:
print(f"{server_address} Connected")
except Error as err:
print(f"Can not connect to db. {err} Occured")
check_server("25.13.253.67")

SSL Handshake issue with asyncio motor driver Mongodb Python

I am trying to connect Mongodb using AWS lambda but results SSL handshake error. I am using motor and Python 3.8 . There is successful connection to database most of time. When I look AWS cloud watchlogs , I found a error connecting to database in some logs.
This is code for connecting database.
from fastapi import FastAPI
from motor.motor_asyncio import AsyncIOMotorClient
from .mongodb import db
import certifi
from app.utility.config import MONGODB_URL
async def connect_to_mongo(app: FastAPI) -> None
db.client = AsyncIOMotorClient(str(MONGODB_URL),tls = True, tlsCAFile= certifi.where(),
maxPoolSize=MAX_CONNECTIONS_COUNT,
minPoolSize=MIN_CONNECTIONS_COUNT,
waitQueueMultiple = MAX_DB_THREADS_WAIT_COUNT,
waitQueueTimeoutMS = MAX_DB_THREAD_QUEUE_TIMEOUT_COUNT )
async def close_mongo_connection(app: FastAPI) -> None:
db.client.close()
Traceback
File "/var/task/pymongo/pool.py", line 1040, in _configured_socket
sock = ssl_context.wrap_socket(sock, server_hostname=host)
File "/var/lang/lib/python3.8/ssl.py", line 500, in wrap_socket
return self.sslsocket_class._create(
File "/var/lang/lib/python3.8/ssl.py", line 1040, in _create
self.do_handshake()
File "/var/lang/lib/python3.8/ssl.py", line 1309, in do_handshake
self._sslobj.do_handshake()
socket.timeout: _ssl.c:1114: The handshake operation timed out
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/var/task/pymongo/mongo_client.py", line 1869, in _process_periodic_tasks
self._topology.update_pool(self.__all_credentials)
File "/var/task/pymongo/topology.py", line 456, in update_pool
server.pool.remove_stale_sockets(generation, all_credentials)
File "/var/task/pymongo/pool.py", line 1252, in remove_stale_sockets
sock_info = self.connect(all_credentials)
File "/var/task/pymongo/pool.py", line 1280, in connect
sock = _configured_socket(self.address, self.opts)
File "/var/task/pymongo/pool.py", line 1053, in _configured_socket
_raise_connection_failure(address, exc, "SSL handshake failed: ")
File "/var/task/pymongo/pool.py", line 238, in _raise_connection_failure
raise NetworkTimeout(msg)
pymongo.errors.NetworkTimeout: SSL handshake failed: cluster0-***-******mongodb.net:******: _ssl.c:1114: The handshake operation timed out

How to handle errors: Pyntc ssh to network device

I am new to network automation, and trying to use pyntc to ssh to the device. I am not sure how to write the code correctly to handle the ssh timeout or authentication error, etc.
My code is as below:
from pyntc import ntc_device as NTC
from pyntc_devices_list import Get_Devices_List
all_devices = Get_Devices_List()
for device in all_devices:
print('Backing up ' + device['name'])
DEVICE = NTC(host=device['ip'], username=device['username'], password=device['password'], device_type='cisco_ios$
try:
DEVICE.open()
except Exception:
print('Error')
continue
back_config = DEVICE.backup_running_config(device['name'] + '.cfg')
DEVICE.close()
I manually turned off this device, and then I found python code was quit:
root#Network-Automation:~/Pyntc# python3 pyntc_error_handling.py
Backing up ESW1
Traceback (most recent call last):
File "/usr/local/lib/python3.5/dist-packages/netmiko/base_connection.py", line 884, in establish_connection
self.remote_conn_pre.connect(**ssh_connect_params)
File "/usr/local/lib/python3.5/dist-packages/paramiko/client.py", line 368, in connect
raise NoValidConnectionsError(errors)
paramiko.ssh_exception.NoValidConnectionsError: [Errno None] Unable to connect to port 22 on 192.168.122.72
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "pyntc_error_handling.py", line 8, in <module>
DEVICE = NTC(host=device['ip'], username=device['username'], password=device['password'], device_type='cisco_ios_ssh')
File "/usr/local/lib/python3.5/dist-packages/pyntc/__init__.py", line 38, in ntc_device
return device_class(*args, **kwargs)
File "/usr/local/lib/python3.5/dist-packages/pyntc/devices/ios_device.py", line 42, in __init__
self.open()
File "/usr/local/lib/python3.5/dist-packages/pyntc/devices/ios_device.py", line 300, in open
verbose=False,
File "/usr/local/lib/python3.5/dist-packages/netmiko/ssh_dispatcher.py", line 246, in ConnectHandler
return ConnectionClass(*args, **kwargs)
File "/usr/local/lib/python3.5/dist-packages/netmiko/base_connection.py", line 317, in __init__
self._open()
File "/usr/local/lib/python3.5/dist-packages/netmiko/base_connection.py", line 322, in _open
self.establish_connection()
File "/usr/local/lib/python3.5/dist-packages/netmiko/base_connection.py", line 890, in establish_connection
raise NetMikoTimeoutException(msg)
netmiko.ssh_exception.NetMikoTimeoutException: Connection to device timed-out: cisco_ios 192.168.122.72:22
Looks like there are more than 1 errors ...

You are doing a minor mistake here, you are expecting an error than trying to same the output. In case of error, the script will through an error. Try it this way.
from pyntc import ntc_device as NTC
from pyntc_devices_list import Get_Devices_List
all_devices = Get_Devices_List()
try:
for device in all_devices:
print('Backing up ' + device['name'])
DEVICE = NTC(host=device['ip'], username=device['username'], password=device['password'], device_type='cisco_ios')
DEVICE.open()
back_config = DEVICE.backup_running_config(device['name'] + '.cfg')
DEVICE.close()
except Exception as Err:
print(Err)

How to check if there is internet connection

I Have to check if my computer is connected to internet (so if i open the broswer i can or i cannot visit an url) , for do this task i tried with some codes:
The first is
import socket
def internet_on():
try:
print("checking internet connection..")
socket.setdefaulttimeout(5)
host = socket.gethostbyname("www.google.com")
s = socket.create_connection((host, 80), 2)
s.close()
print('internet on.')
return True
except Exception as e:
print(e)
print("internet off.")
return False
internet_on()
code that i took from this answer Checking internet connection with Python
After i tried with this:
from urllib.request import urlopen
def internet_on():
try:
urlopen("https://www.instagram.com/", timeout=5)
return True
except Exception as err:
print(str(err))
return False
internet_on()
code that i took from this answer Checking network connection
And this
import socket
REMOTE_SERVER = "www.google.com"
def internet_on(hostname):
try:
# see if we can resolve the host name -- tells us if there is
# a DNS listening
host = socket.gethostbyname(hostname)
# connect to the host -- tells us if the host is actually
# reachable
s = socket.create_connection((host, 80), 2)
return True
except Exception:
return False
internet_on(REMOTE_SERVER)
code that i took from this answer Test if an internet connection is present in python
If the connection is active the codes work fines
but when there is no connection all this codes raise the same errors:
Traceback (most recent call last):
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\urllib3\connection.py", line 159, in _new_conn
(self._dns_host, self.port), self.timeout, **extra_kw)
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\urllib3\util\connection.py", line 57, in create_connection
for res in socket.getaddrinfo(host, port, family, socket.SOCK_STREAM):
File "C:\Program Files\Python37-32\lib\socket.py", line 748, in getaddrinfo
for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno 11001] getaddrinfo failed
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\urllib3\connectionpool.py", line 600, in urlopen
chunked=chunked)
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\urllib3\connectionpool.py", line 343, in _make_request
self._validate_conn(conn)
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\urllib3\connectionpool.py", line 839, in _validate_conn
conn.connect()
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\urllib3\connection.py", line 301, in connect
conn = self._new_conn()
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\urllib3\connection.py", line 168, in _new_conn
self, "Failed to establish a new connection: %s" % e)
urllib3.exceptions.NewConnectionError: <urllib3.connection.VerifiedHTTPSConnection object at 0x03B39E90>: Failed to establish a new connection: [Errno 11001] getaddrinfo failed
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\requests\adapters.py", line 449, in send
timeout=timeout
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\urllib3\connectionpool.py", line 638, in urlopen
_stacktrace=sys.exc_info()[2])
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\urllib3\util\retry.py", line 398, in increment
raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='www.instagram.com', port=443): Max retries exceeded with url: /_exploreurself (Caused by NewConnectionError('<urllib3.connection.VerifiedHTTPSConnection object at 0x03B39E90>: Failed to establish a new connection: [Errno 11001] getaddrinfo failed'))
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:/Users/mcara/OneDrive/Desktop/file InstaBot da editare/v0.4/bot.py", line 835, in <module>
bot.unfollow_process(RANDOM, sense=UP_DOWN, following_target=0, sleep_time=60)
File "C:/Users/mcara/OneDrive/Desktop/file InstaBot da editare/v0.4/bot.py", line 651, in unfollow_process
current_following = self.user_following_num(self._username)
File "C:/Users/mcara/OneDrive/Desktop/file InstaBot da editare/v0.4/bot.py", line 387, in user_following_num
r = requests.get(url).text
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\requests\api.py", line 75, in get
return request('get', url, params=params, **kwargs)
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\requests\api.py", line 60, in request
return session.request(method=method, url=url, **kwargs)
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\requests\sessions.py", line 533, in request
resp = self.send(prep, **send_kwargs)
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\requests\sessions.py", line 646, in send
r = adapter.send(request, **kwargs)
File "C:\Users\mcara\PycharmProjects\1\venv\lib\site-packages\requests\adapters.py", line 516, in send
raise ConnectionError(e, request=request)
requests.exceptions.ConnectionError: HTTPSConnectionPool(host='www.instagram.com', port=443): Max retries exceeded with url: /_exploreurself (Caused by NewConnectionError('<urllib3.connection.VerifiedHTTPSConnection object at 0x03B39E90>: Failed to establish a new connection: [Errno 11001] getaddrinfo failed'))

Try this one here IP address 216.58.192.142 is one of Google's IP address. Due to static IP address, this code is not robust and may not work always so, replace this IP address with some other website which you believe respond more faster.
The reason why the code uses a fixed IP address instead of a fully qualified domain name (FQDN) is because a FQDN would require a DNS lookup. When the machine does not have a working internet connection, the DNS lookup itself may block the call to urllib_request.urlopen for more than a second.
import urllib2
def internet_on():
try:
urllib2.urlopen('http://216.58.192.142', timeout=1)
return True
except urllib2.URLError as err:
return False

Try to run a ping to www.google.com with the library 'subprocess', an example of code below. This solution is an indirect one, but sometimes is better to delegate in system commands to do certain jobs like this one.
import subprocess
def my_dir(my_path):
output=''
try:
p = subprocess.Popen('ping '+my_path, stdout = subprocess.PIPE, stderr = subprocess.STDOUT,
#close_fds = True, #not valid for Windows platforms
shell = True
)
output, err = p.communicate()
#print(output)
finally:
if p is not None:
try: p.kill()
except: pass
return output
print(my_dir('www.google.com'))
Then, you can parse its output to know if you have reached Google's servers or not.

Python Scraper - Socket Error breaks script if target is 404'd

Encountered an error while building a web scraper to compile data and output into XLS format; when testing again a list of domains in which I wish to scrape from, the program faulters when it recieves a socket error. Hoping to find an 'if' statement that would null parsing a broken website and continue through my while-loop. Any ideas?
workingList = xlrd.open_workbook(listSelection)
workingSheet = workingList.sheet_by_index(0)
destinationList = xlwt.Workbook()
destinationSheet = destinationList.add_sheet('Gathered')
startX = 1
startY = 0
while startX != 21:
workingCell = workingSheet.cell(startX,startY).value
print ''
print ''
print ''
print workingCell
#Setup
preSite = 'http://www.'+workingCell
theSite = urlopen(preSite).read()
currentSite = BeautifulSoup(theSite)
destinationSheet.write(startX,0,workingCell)
And here's the error:
Traceback (most recent call last):
File "<pyshell#2>", line 1, in <module>
homeMenu()
File "C:\Python27\farming.py", line 31, in homeMenu
openList()
File "C:\Python27\farming.py", line 79, in openList
openList()
File "C:\Python27\farming.py", line 83, in openList
openList()
File "C:\Python27\farming.py", line 86, in openList
homeMenu()
File "C:\Python27\farming.py", line 34, in homeMenu
startScrape()
File "C:\Python27\farming.py", line 112, in startScrape
theSite = urlopen(preSite).read()
File "C:\Python27\lib\urllib.py", line 84, in urlopen
return opener.open(url)
File "C:\Python27\lib\urllib.py", line 205, in open
return getattr(self, name)(url)
File "C:\Python27\lib\urllib.py", line 342, in open_http
h.endheaders(data)
File "C:\Python27\lib\httplib.py", line 951, in endheaders
self._send_output(message_body)
File "C:\Python27\lib\httplib.py", line 811, in _send_output
self.send(msg)
File "C:\Python27\lib\httplib.py", line 773, in send
self.connect()
File "C:\Python27\lib\httplib.py", line 754, in connect
self.timeout, self.source_address)
File "C:\Python27\lib\socket.py", line 553, in create_connection
for res in getaddrinfo(host, port, 0, SOCK_STREAM):
IOError: [Errno socket error] [Errno 11004] getaddrinfo failed

Ummm that looks like the error I get when my internet connection is down. HTTP 404 errors are what you get when you do have a connection but the URL that you specify can't be found.
There's no if statement to handle exceptions; you need to "catch" them using the try/except construct.
Update: Here's a demonstration:
import urllib
def getconn(url):
try:
conn = urllib.urlopen(url)
return conn, None
except IOError as e:
return None, e
urls = """
qwerty
http://www.foo.bar.net
http://www.google.com
http://www.google.com/nonesuch
"""
for url in urls.split():
print
print url
conn, exc = getconn(url)
if conn:
print "connected; HTTP response is", conn.getcode()
else:
print "failed"
print exc.__class__.__name__
print str(exc)
print exc.args
Output:
qwerty
failed
IOError
[Errno 2] The system cannot find the file specified: 'qwerty'
(2, 'The system cannot find the file specified')
http://www.foo.bar.net
failed
IOError
[Errno socket error] [Errno 11004] getaddrinfo failed
('socket error', gaierror(11004, 'getaddrinfo failed'))
http://www.google.com
connected; HTTP response is 200
http://www.google.com/nonesuch
connected; HTTP response is 404
Note that so far we have just opened the connection. Now what you need to do is check the HTTP response code and decide whether there is anything worth retrieving using conn.read()