OpenTelemetry Monolog handler

A monolog handler for OpenTelemetry. See https://opentelemetry.io/docs/instrumentation/php/manual/#logs for further documentation.

Requirements

API + SDK

This package depends on the OpenTelemetry API, but a configured OpenTelemetry SDK should also be provided.

Exporter

Usually logs are exported to a receiver via the otlp protocol in the protobuf format, via http or gRPC.

This requires:

a protobuf implementation; either the protobuf extension or the google/protobuf package
the open-telemetry/exporter-otlp package
the open-telemetry/transport-grpc package, if using gRPC transport
a PSR-7 and PSR-18 implementation, if using HTTP transport

Receiver

Logs must be emitted to a receiver/system that understands the OpenTelemetry protocol, such as the OpenTelemetry collector.

Installation

composer require open-telemetry/opentelemetry-logger-monolog

Usage

The OpenTelemetry handler, configured with an OpenTelemetry LoggerProvider, is used to send Monolog LogRecords to OpenTelemetry.

The LoggerProvider can be configured in a number of ways: manually, via an SDK Builder, or automatically (using environment/php.ini variables).

Manual configuration

Set up an SDK LoggerProvider and pass it to the handler:

$loggerProvider = new \OpenTelemetry\SDK\Logs\LoggerProvider(/* params */);
$handler = new \OpenTelemetry\Contrib\Logs\Monolog\Handler(
    $loggerProvider,
    'info',
    true,
);

Automatic configuration

If you use OpenTelemetry SDK autoloading, you can retrieve the global logger provider. That may be a no-op implementation if there was any misconfiguration.

See autoload-sdk example for how to use autoloading with the OpenTelemetry SDK.

Create a Logger

Finally, add the handler to a Monolog logger:

$logger = new \Monolog\Logger(
    'name',
    [$handler],
);
$logger->info('hello world');