OpenTelemetry PHP exporter

To install the exporter through Composer, run the following command:

composer require open-telemetry/opentelemetry-exporter-instana

You can create and configure the exporter in three ways:

• Using the Instana SpanFactory
• Configuring the SpanExporter instance manually
• Using the OpenTelemetry registry

To use the exporter, complete the following steps:

1. Install the composer package into your project.
2. Create an instance of the InstanaExporter.

You must provide the following two Instana environment variables to the application for the factory and registry:

INSTANA_AGENT_HOST
INSTANA_AGENT_PORT 

If the INSTANA_AGENT_HOST and INSTANA_AGENT_PORT environment variables are not set, the following default values are used:

INSTANA_AGENT_HOST=127.0.0.1
INSTANA_AGENT_PORT=42699

$tracerProvider = new TracerProvider(
    new SimpleSpanProcessor(
        (new \Instana\SpanExporterFactory)->create()
    )
);

To manually configure SpanExporter, run the following command:

$transport = new InstanaTransport('127.0.0.1:42699');
$exporter =  new SpanExporter(
        $transport, 
        new SpanConverter($transport->getUuid(), $transport->getPid())
);
$tracerProvider = new TracerProvider(
    new SimpleSpanProcessor($exporter)
);

To configure the exporter by using the OpenTelemetry registry, use the key "instana" when you construct a span exporter:

$tracerProvider = new TracerProvider(
    new SimpleSpanProcessor(
        Registry::spanExporterFactory("instana")->create()
    )
);

After the tracer provider is set up, you can initialize an OpenTelemetry PHP tracer and use the SDK as normal.

$tracer = $tracerProvider->getTracer('io.instana.opentelemetry.php');

$span = $tracer->spanBuilder('root')->startSpan();
$span->setAttribute('remote_ip', '1.2.3.4')
    ->setAttribute('country', 'CAN');
$span->addEvent('generated_session', [
    'id' => md5((string) microtime(true)),
]);
$span->end();

$tracerProvider->shutdown();

The exporter supports auto-instrumentation, and you can configure the exporter in conjunction with the OpenTelemetry SDK. To enable auto-instrumentation, use the following environment variables or configure the php.ini file:

OTEL_PHP_AUTOLOAD_ENABLED=true
OTEL_TRACES_EXPORTER=instana
OTEL_PROPAGATORS=instana,baggage

After you configure the exporter, the traces that are exported to the Instana agent are installed in your application. The traces are dependent on the instrumentation libraries. Therefore, you must add the appropriate instrumentation libraries that your application requires.

composer require open-telemetry/opentelemetry-auto-curl
composer require open-telemetry/opentelemetry-auto-wordpress

You can define a custom service name for your application by using the environment variables INSTANA_SERVICE_NAME or OTEL_SERVICE_NAME. If both variables are present, the value of INSTANA_SERVICE_NAME takes precedence over OTEL_SERVICE_NAME.

In the PHP Instana exporter, you can capture the custom HTTP headers from both requests and responses by using the environment variables. You can use the following environment variables to specify the custom HTTP headers:

OTEL_PHP_INSTRUMENTATION_HTTP_RESPONSE_HEADERS=content-type,server
OTEL_PHP_INSTRUMENTATION_HTTP_REQUEST_HEADERS=host,accept

The Instana PHP exporter supports the following types of context propagation for distributed tracing:

• W3C trace context propagation: Enabled by default.
• Instana native trace context propagation: Not enabled by default. To enable Instana trace context propagation, use the Instana OpenTelemetry propagator.

See OpenTelemetry Instana propagator for more details.