Precisely Catch DNS Error With Python Requests

I am trying to make a check for expired domain name with python-requests. import requests try: status = requests.head('http://wowsucherror') except requests.ConnectionError a

Solution 1:

Done this with this hack, but please monitor https://github.com/psf/requests/issues/3630 for a proper way to appear.

# for Python 2 compatibility
from __future__ import print_function
import requests

def sitecheck(url):
    status = None
    message = ''
    try:
        resp = requests.head('http://' + url)
        status = str(resp.status_code)
    if ("[Errno 11001] getaddrinfo failed" in str(exc) or     # Windows
        "[Errno -2] Name or service not known" in str(exc) or # Linux
        "[Errno 8] nodename nor servname " in str(exc)):      # OS X
        message = 'DNSLookupError'
    else:
        raise

    return url, status, message

print(sitecheck('wowsucherror'))
print(sitecheck('google.com'))

Solution 2:

You could use lower-level network interface, socket.getaddrinfo https://docs.python.org/3/library/socket.html#socket.getaddrinfo

import socket


def dns_lookup(host):
    try:
        socket.getaddrinfo(host, 80)
    except socket.gaierror:
        return False
    return True


print(dns_lookup('wowsucherror'))
print(dns_lookup('google.com'))

Solution 3:

I have a function based on the earlier answer above which seems to no longer work. This function checks "liveness" of a url based on resolution and also the requests .ok function rather than just specific to resolution errors but can be adapted easily to suit.

def check_live(url):
    try:
        r = requests.get(url)
        live = r.ok
    except requests.ConnectionError as e:
        if 'MaxRetryError' not in str(e.args) or 'NewConnectionError' not in str(e.args):
            raise
        if "[Errno 8]" in str(e) or "[Errno 11001]" in str(e) or ["Errno -2"] in str(e):
            print('DNSLookupError')
            live = False
        else:
            raise
    except:
        raise
    return live