How to Enable Error Logging on PHP-FPM 7 with Nginx

This guide outlines the steps to enable error logging for PHP-FPM 7 when used in conjunction with Nginx web server. Proper error logging is crucial for debugging and identifying issues within your PHP applications.

Steps to Enable PHP-FPM Error Logging:

1. Locate the PHP-FPM Configuration File:

   The PHP-FPM configuration file is typically named php-fpm.conf or php-fpm.ini and resides in a directory such as /etc/php/7.x/fpm/ or /usr/local/etc/php/7.x/fpm/. Replace 7.x with your specific PHP version.

   Common locations:

   • /etc/php/7.x/fpm/php-fpm.conf
   • /etc/php/7.x/fpm/php.ini
   • /usr/local/etc/php/7.x/fpm/php-fpm.conf
   • /usr/local/etc/php/7.x/fpm/php.ini
2. Configure Error Logging in php.ini:

   Edit the php.ini file (often referenced from within php-fpm.conf) and set the following directives:

   error_reporting = E_ALL
   log_errors = On
   error_log = /path/to/your/php-fpm-errors.log
   

   Replace /path/to/your/php-fpm-errors.log with the desired path to your log file. Ensure the user running PHP-FPM (usually www-data or nginx) has write access to this file and its directory.

   • error_reporting = E_ALL: This sets the error reporting level to report all errors, warnings, and notices.
   • log_errors = On: This enables error logging.
   • error_log = /path/to/your/php-fpm-errors.log: This specifies the path to the error log file.
3. Verify Pool Configuration (www.conf or similar):

   Navigate to the pool configuration file (usually www.conf or similar, located in /etc/php/7.x/fpm/pool.d/ or a similar directory). Ensure error logging is configured within the pool. Check for specific overrides that might disable or redirect the logs configured in php.ini.

   ; Example www.conf snippet
   [www]
   ; ... other settings ...
   php_flag[display_errors] = off
   php_admin_value[error_log] = /path/to/your/php-fpm-pool-errors.log
   php_admin_flag[log_errors] = on
   php_admin_value[error_reporting] = E_ALL
   

   Again, ensure the appropriate user has write access to the log file.

4. Restart PHP-FPM:

   Restart the PHP-FPM service to apply the changes.

   sudo systemctl restart php7.x-fpm  # Replace 7.x with your version
   

   Or, depending on your system:

   sudo service php7.x-fpm restart # Replace 7.x with your version
   

5. Configure Nginx:

   While PHP-FPM handles PHP execution errors, Nginx can also log errors related to serving the requests. Check your Nginx virtual host configuration (usually in /etc/nginx/sites-available/) and ensure you have error logging enabled.

   server {
       # ... other settings ...
       error_log /path/to/your/nginx-error.log error;
       # ...
   }
   

   Replace /path/to/your/nginx-error.log with the desired path.

6. Restart Nginx:

   Restart Nginx to apply the changes.

   sudo systemctl restart nginx
   

   Or, depending on your system:

   sudo service nginx restart
   

7. Test and Verify:

   Create a simple PHP script with an intentional error and access it through your web browser. Check both the PHP-FPM error log (/path/to/your/php-fpm-errors.log) and the Nginx error log (/path/to/your/nginx-error.log) to confirm that the error is being logged correctly.

Important Considerations:

• Permissions: Ensure the user running PHP-FPM has write access to the error log file and its directory. This is often the www-data or nginx user.
• Security: Do *not* display errors directly to the user in a production environment. This can expose sensitive information. Use error logging for debugging only.
• Log Rotation: Implement a log rotation mechanism (e.g., logrotate) to prevent your error logs from consuming excessive disk space.
• Debugging: Use the error logs to identify and resolve issues within your PHP applications.