To configure Nginx to pass client IP addresses to PHP-FPM, you will need to make some changes to your Nginx configuration file. Here's how you can do it:
Open your Nginx configuration file. Depending on your Linux distribution, the file may be located in different directories. Commonly, it is located at /etc/nginx/nginx.conf or /etc/nginx/sites-available/default.
Look for the http block in the configuration file. This is where you define global configuration settings for Nginx.
Inside the http block, add the following line:
real_ip_header X-Forwarded-For;
This line tells Nginx to read the X-Forwarded-For header to obtain the client's IP address.
Add the following line to specify the trusted proxy IP addresses:
set_real_ip_from <proxy IP>;
Replace <proxy IP> with the IP address of the proxy server. If you have multiple proxy servers, add multiple set_real_ip_from lines.
Save the configuration file.
Test the configuration to make sure there are no syntax errors:
sudo nginx -t
If the test is successful, reload the Nginx configuration to apply the changes:
sudo systemctl reload nginx
Now, Nginx should forward the client's IP address to PHP-FPM in the $_SERVER['REMOTE_ADDR'] variable. You can verify this by checking the REMOTE_ADDR variable in your PHP application.