NewRelic - Add custom fields to the logs

Question

I am currently using NewRelic and am experiencing a lot of difficulties in retrieving logs with custom fields (for example, allowing for faceted search).

My goal is to manage to retrieve logs in NewRelic in the following format:

{
    entity.guid: NDI0MTk5MnxBUE18QVBQTElDQVRJT058NTMzMDg2MzM5,
    entity.guids: NDI0MTk5MnxBUE18QVBQTElDQVRJT058NTMzMDg2MzM5,
    entity.name: foxnot,
    hostname: poc-new-relic-web-1,
    level: ERROR,
    message: info,
    newrelic.source: logs.APM,
    span.id: 0295c53b980e73dd,
    timestamp: 1701161680672,
    trace.id: b83046772a0a770d,
    custom_field_1: [email protected],
    custom_field_2: myvalue
}

Here is my technical context:

• PHP 8.2,
• Symfony 6,
• Monolog,
• PHP APM Agent installed.

Here is an example of a log that is properly retrieved from Symfony, but whose context fields are systematically ignored.

    #[Route('/test', name: 'test')]
    public function index(LoggerInterface $logger): JsonResponse
    {
        $logger->error("info", context: ["user_email" => "[email protected]"]);
        $logger->info("mon_info", context: ["user_email" => "[email protected]"]);
        return new JsonResponse(['message' => 'hello']);
    }

when@prod:
    monolog:
        handlers:
            main:
                type: fingers_crossed
                action_level: error
                handler: nested
                excluded_http_codes: [404, 405]
                formatter: 'monolog.formatter.json'
                buffer_size: 50 # How many messages should be saved? Prevent memory leaks
            nested:
                type: stream
                path: php://stderr
                level: debug
                formatter: monolog.formatter.json
            console:
                type: console
                process_psr_3_messages: false
                channels: ["!event", "!doctrine"]
            deprecation:
                type: stream
                channels: [deprecation]
                path: php://stderr

How can I ensure that the logs are retrieved with the custom fields?

I attempted using the Rest API directly, but it does not meet the requirements in terms of securing the response time. I tried using newrelic_add_custom_parameter, but without any result

Thanks in advance