Date Published: February 5, 2025
Setting CF-IPCountry as a response header via PHP
This guide will show you how to create a simple module to capture the CF-IPCountry header incoming from Cloudflare (https://support.cloudflare.com/hc/en-us/articles/200168236-Configuring-Cloudflare-IP-Geolocation) and set it to the response headers using an Event Subscriber.
Warning
Drupal page cache does not respect the Vary header, please ensure that you read Drupal 8 page cache does not respect the Vary header
Note Acquia Edge does not respect the "Vary" header !
Create a custom module using the following structure replacing cf_header and CfSubscriber with the names of your choice:
Edit the CfSubscriber.php file to contain the below, modifying the namespace and class name appropriately:
<?php
namespace Drupal\cf_header\EventSubscriber; #<-- MODIFY THIS
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
use Symfony\Component\HttpFoundation\RequestStack;
/**
* Class CfSubscriber. <-- MODIFY THIS
*/
class CfSubscriber implements EventSubscriberInterface { #<-- MODIFY THIS
/**
* Symfony\Component\HttpFoundation\RequestStack definition.
*
* @var \Symfony\Component\HttpFoundation\RequestStack
*/
protected $requestStack;
/**
* Constructs a new CfSubscriber object. <-- MODIFY THIS
*
* @param \Symfony\Component\HttpFoundation\RequestStack $request_stack
*/
public function __construct(RequestStack $request_stack) {
$this->requestStack = $request_stack;
}
/**
* {@inheritdoc}
*/
public static function getSubscribedEvents() {
$events['kernel.response'] = ['kernelResponse'];
return $events;
}
/**
* This method is called when the kernel.response is dispatched.
*
* @param \Symfony\Component\HttpKernel\Event\FilterResponseEvent $event
* The dispatched event.
*/
public function kernelResponse(FilterResponseEvent $event) {
$request = $this->requestStack->getCurrentRequest();
$headers = $request->headers->get('CF-IPCountry');
$response = $event->getResponse();
$response->headers->set('CF-IPCountry', $headers);
}
}
Edit cf_header.services.yaml to contain the below, modifying service name and cla name appropriately:
services:
cf_header.default: # <-- MODIFY THIS
class: Drupal\cf_header\EventSubscriber\CfSubscriber # <-- MODIFY THIS
arguments: ['@request_stack']
tags:
- { name: event_subscriber }
You can now enable the module on your site which will capture the request header and set it to the response.
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