Exception logging

Tools can separate selected HTTP exceptions into a 404 log scope. The default mappings include not-found and unauthorized exceptions; the source defines the complete list.

Configure logging

In config/bootstrap.php, configure the scoped logger:

use Cake\Log\Log;

Log::setConfig('404', [
    'className' => 'File',
    'path' => LOGS,
    'file' => '404',
    'levels' => ['error'],
    'scopes' => ['404'],
]);

Set scopes to null in the existing Log.debug and Log.error entries in config/app.php if those engines should accept only unscoped messages. Preserve their other settings. An empty list accepts all scopes and can duplicate these records.

Replace the exception trap

In config/bootstrap.php, replace the core ExceptionTrap import with Tools\Error\ExceptionTrap. Keep CakePHP's ErrorTrap:

use Cake\Core\Configure;
use Cake\Error\ErrorTrap;
use Tools\Error\ExceptionTrap;

(new ErrorTrap(Configure::read('Error')))->register();
(new ExceptionTrap(Configure::read('Error')))->register();

In Application::middleware(), replace the existing core error middleware with the Tools middleware. Import Tools\Error\Middleware\ErrorHandlerMiddleware instead of its core counterpart and preserve the rest of the middleware queue:

$middlewareQueue->add(new ErrorHandlerMiddleware(Configure::read('Error')));

Requests referred from the application's own configured host remain in the normal error log when the exception trap receives that request context. This helps identify broken internal links. External requests matching the configured mappings use the 404 scope.

Customize mappings

Error.log404 replaces the default exception list. For example, add this setting to the existing Error configuration to scope only not-found exceptions:

'log404' => [Cake\Http\Exception\NotFoundException::class],

The DatabaseLog monitor can report recorded errors when database logging is configured.