hookdns

HookDNS is a library which allow you to modify a name resolution in your Python script without any modification in your hosts file or by using a fake DNS resolver.

import requests

from hookdns import hosts

with hosts({"example.org": "127.0.0.1"}):
    ...
    r = requests.get("http://example.org")  # the request is sent to your local server
    ...

Installation

pip install hookdns

Usage

Custom DNS resolutions are describe by a dictionnary where the keys are hostnames and the values the expected corresponding addresses.

{
    "hostname1": "addr1",
    "hostname2": "addr2"
}

hostname and addr could be a domain name or a string representation of an IPv4/IPV6.

Example using the patch as a decorator

import requests

from hookdns import hosts

@hosts({"example.org": "127.0.0.1"})
def myfunc():
    ...
    r = requests.get("http://example.org")  # the request is sent to your local server
    ...

Example using the patch as a context manager

import requests

from hookdns import hosts

with hosts({"example.org": "localhost"}):
    ...
    r = requests.get("http://example.org")  # the request is sent to your local server
    ...

Options

By default the following function calls are intercepted: socket.gethostbyname, socket.gethostbyname_ex and socket.getaddrinfo.

You can limit the interception to only a restricted list of function.

import socket

from hookdns import hosts

with hosts({"example.org": "localhost"}, only=["gethostbyname"]):
    ...
    addr = socket.gethostbyname("example.org")  # returns "127.0.0.1"
    print("gethostname returns: %s" % addr)

    _, _, addr = socket.gethostbyname_ex("example.org")  # returns the real ip address for example.org
    print("gethostname_ex returns: %s" % addr[0])
    ...    

gethostname returns: 127.0.0.1
gethostname_ex returns: 93.184.216.34