feat: adding OpenTelemetry option

[kazagz]

closes #1120

Description

This feature allows sending telemetry data about journeys to OTEL endpoints. It can be enabled by setting otel: true in SyntheticsConfig (aka synthetics.config.ts) or by adding --otel flag when running from command line. Endpoints, protocols and other parameters are being set with standard OTEL environment parameters. Example below:

export OTEL_EXPORTER_OTLP_ENDPOINT="https://your-otel.net"
export OTEL_EXPORTER_OTLP_PROTOCOL="grpc"
export OTEL_SERVICE_NAME="elastic-synthetics"
export OTEL_RESOURCE_ATTRIBUTES="deployment.environment.name=dev"

If --rich-events are enabled, it will also record network and console events.

Journey

Nothing changes in journey definition.

import { step, monitor, journey } from '@elastic/synthetics';

journey('www.elastic.co', ({ page }) => {
  monitor.use({
    id: 'elastic',
    schedule: 5,
    enabled: true,
    tags: ['elastic', 'test'],
    fields: {
      pull: '1121',
      repo: 'https://github.com/elastic/synthetics',
    },
  });

  step('Open Elastic page', async () => {
    await page.goto('https://www.elastic.co/');
  });

  step('Explore Elastic', async () => {
    await page.getByRole('link', { name: 'Explore Elastic' }).click();
  });
});

Trace

These are details you see when journey is executed and traces sent to EDOT.

Dependencies

Dependency view shows all easy to understand information about all connections made by journey.