http://api.ipify.org/ doesn't support ipv6

[sybrew]

Prerequisites

• I have carried out troubleshooting steps and I believe I have found a bug.
• I have searched for similar bugs in both open and closed issues and cannot find a duplicate.

Describe the bug

In WC_Geolocation::$ip_lookup_apis, various APIs are appointed to obtain the host's IP address. Unlike all other IPs, ipify doesn't support IPv6, which may cause a headache when debugging lookups.

This is likely inconsequential, but it may also trickle down into executing multiplicable geolocation lookups via WC_Geolocation::geolocate_ip().

Expected behavior

Consistent IPv6 and IPv4 support across the board.

Actual behavior

Inconsistent IPv6 and IPv4 support.

Steps to reproduce

Run this on a server with mixed IPv6 and IPv4 support. It will crash if the site is unreachable, but eh... it's for testing purposes.

add_action(
	'init',
	function () {
		var_dump( wp_safe_remote_get(
			'http://api.ipify.org/', // change to test other endpoints.
			[
				'timeout'    => 2,
				'user-agent' => 'WooCommerce/' . wc()->version,
			],
		)['body'] );
	},
);

WordPress Environment

N/A

Isolating the problem

• I have deactivated other plugins and confirmed this bug occurs when only WooCommerce plugin is active.
• This bug happens with a default WordPress theme active, or Storefront.
• I can reproduce this bug consistently using the steps above.

[naman03malhotra]

Hi @sybrew, we'd still want to support ipify, as long as it's not in a critical path and does not cause site to crash. Do you see this happening on a server without the code snippet?

[sybrew]

The snippet serves as an example and is not indicative of the real world performance. Still, it proves that, unlike all other providers, IPv6 is not supported and will cause unnecessary calls since it bypasses the cache.