Get Monolog JSON Stack Trace as Array - php

Question

I'm using Laravel 4.2 and want to get logs out as JSON. Laravel uses Monolog, so I've configured the JSON formatter like so:
$logHandler = new Monolog\Handler\StreamHandler(Config::get('app.logFile'), Monolog\Logger::DEBUG);
$logHandler->setFormatter(new Monolog\Formatter\JsonFormatter);
Log::getMonolog()->pushHandler($logHandler);
The problem is that stack traces are included as part of the message string, like so:
{
"message": "exception 'Exception' with message 'Socket operation failed: Host name lookup failure' in /var/www/vendor/clue/socket-raw/Socket/Raw/Socket.php:388\nStack trace:\n#0 /var/www/vendor/clue/socket-raw/So..."
}
Can someone point me in the right direction to make the stack trace its own separate array in the json?

Answer 1

Long overdue update:
The primary problem is that Laravel, and lots of code following its example, tries to log the exception by itself, e.g., Log::error($e). This is the wrong way to log an exception with Monolog. That first parameter is supposed to be a simple message string. In processing it, Monolog\Logger::addRecord() explicitly casts the message to a string:
$record = array(
'message' => (string) $message,
//...
);
If $message is actually an exception, you get the whole stack trace as a string. Unfortunately, this is what Laravel's default exception handler does.
The correct way to get a stack trace as an array is to pass the exception in as context so that it's available non-stringified to the formatter. For instance:
Log::error($e->getMessage(), ['exception' => $e]);
Something equivalent is what you need to put in your custom exception handler for Laravel, and then you can use a proper JSON formatter and get what you except.