Improve error handling for private URLs

[tillkruss]

• [x] If the URL contains localhost or is a local IP like 127.0.0.1 then don't save Instance
• [x] If request times out then show URL that's timing out to avoid issues
• [x] Alert recovery text: Are you trying to access a local address from a remote location?

https://softwareengineering.stackexchange.com/questions/384960/is-my-algorithm-for-determining-whether-a-ipv4-is-public-or-private-correct

[tillkruss]

Testing whether a URL corresponds to a local IP address (such as 127.0.0.1 or addresses within the 10.x.x.x, 172.16.x.x to 172.31.x.x, and 192.168.x.x ranges) can be achieved by parsing the URL and examining its host component. This process involves:

1. Parsing the URL to extract the hostname.
2. Determining if the hostname is a special loopback address (127.0.0.1 or localhost) or falls within private IP address ranges.

Here's a simple example in Python demonstrating how to check if a given URL is local:

from ipaddress import ip_address, ip_network
from urllib.parse import urlparse

def is_local_url(url):
    try:
        parsed_url = urlparse(url)
        host = parsed_url.hostname

        # Check if host is a local IP address (127.0.0.1 or localhost)
        if host in ["localhost", "127.0.0.1"]:
            return True

        # Convert the hostname to an IP address (assumes IPv4 for simplicity)
        ip = ip_address(host)

        # Define private IP address ranges
        private_networks = [
            ip_network("10.0.0.0/8"),
            ip_network("172.16.0.0/12"),
            ip_network("192.168.0.0/16"),
            ip_network("127.0.0.0/8")  # Including the loopback range for completeness
        ]

        # Check if the IP address falls within any of the private ranges
        return any(ip in network for network in private_networks)
    except ValueError:
        # Handle invalid IP addresses
        return False

# Example usage
url = "http://127.0.0.1/path"
print(is_local_url(url))  # True

url = "http://192.168.1.1/path"
print(is_local_url(url))  # True

url = "http://example.com/path"
print(is_local_url(url))  # False

Key Points:

• The ipaddress module is used to work with and check IP addresses.
• The `ur

[tillkruss]

Pattern           Class        Remark 
10.xxx.xxx.xxx      A 
172.YYY.xxx.xxx     B          YYY is between 16 and 31 included
192.168.xxx.xxx     C