PHP - Rocketgraph

PHP auto-instrumentation needs a PECL extension that hooks function calls, plus the Composer packages for the SDK. With both present, Laravel and Symfony requests, PDO queries and Guzzle calls are traced without code changes.

Install

# 1. The hook extension
pecl install opentelemetry
echo "extension=opentelemetry.so" >> "$(php -i | grep '^Loaded Configuration File' | cut -d'>' -f2 | xargs)"

# 2. The SDK and exporter
composer require \
  open-telemetry/sdk \
  open-telemetry/exporter-otlp \
  open-telemetry/opentelemetry-auto-laravel

Swap the last package for opentelemetry-auto-symfony, -auto-slim or -auto-psr18 depending on your framework. Verify the extension loaded with php -m | grep opentelemetry.

Configure

export OTEL_PHP_AUTOLOAD_ENABLED=true
export OTEL_SERVICE_NAME="my-php-service"
export OTEL_EXPORTER_OTLP_ENDPOINT="https://ingress.rocketlog.io"
export OTEL_EXPORTER_OTLP_HEADERS="Authorization=Bearer rg_live_xxxxxx"
export OTEL_EXPORTER_OTLP_PROTOCOL="http/protobuf"
export OTEL_TRACES_EXPORTER=otlp
export OTEL_LOGS_EXPORTER=otlp
export OTEL_METRICS_EXPORTER=otlp

OTEL_PHP_AUTOLOAD_ENABLED=true is the switch that actually turns auto-instrumentation on. Everything else can be correct and nothing will be exported without it.

Under PHP-FPM

Shell exports do not reach FPM workers. Set them in the pool config instead:

; /usr/local/etc/php-fpm.d/www.conf
env[OTEL_PHP_AUTOLOAD_ENABLED] = true
env[OTEL_SERVICE_NAME] = my-php-service
env[OTEL_EXPORTER_OTLP_ENDPOINT] = https://ingress.rocketlog.io
env[OTEL_EXPORTER_OTLP_PROTOCOL] = http/protobuf
env[OTEL_EXPORTER_OTLP_HEADERS] = Authorization=Bearer rg_live_xxxxxx

Custom spans

use OpenTelemetry\API\Globals;

$tracer = Globals::tracerProvider()->getTracer('payments');

$span = $tracer->spanBuilder('settle-transfer')->startSpan();
$scope = $span->activate();

try {
    $span->setAttribute('transfer.id', $transferId);
    settle($transferId);
} catch (\Throwable $e) {
    $span->recordException($e);
    throw $e;
} finally {
    $scope->detach();
    $span->end();
}