tracer.ts

import { NodeSDK } from '@opentelemetry/sdk-node';
import { getNodeAutoInstrumentations } from '@opentelemetry/auto-instrumentations-node';
import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-proto';
import { PrometheusExporter } from '@opentelemetry/exporter-prometheus';
import { MeterProvider, PeriodicExportingMetricReader } from '@opentelemetry/sdk-metrics';
import { Resource } from '@opentelemetry/resources';
import { SemanticResourceAttributes } from '@opentelemetry/semantic-conventions';
import { ParentBasedSampler, TraceIdRatioBasedSampler } from '@opentelemetry/sdk-trace-base'
import { OurSampler } from './ourSampler';
import {W3CBaggagePropagator, W3CTraceContextPropagator, CompositePropagator} from '@opentelemetry/core'
import { OTLPMetricExporter} from '@opentelemetry/exporter-metrics-otlp-proto'

function start(serviceName: string) {

    const { endpoint, port } = PrometheusExporter.DEFAULT_OPTIONS;
    // const exporter = new PrometheusExporter({}, () => {
    //     console.log(
    //         `prometheus scrape endpoint: http://localhost:${port}${endpoint}`,
    //     );
    // });
    const meterProvider = new MeterProvider({
        resource: new Resource({
            [SemanticResourceAttributes.SERVICE_NAME]: serviceName,
        }),
    }); 
    const metricReader = new PeriodicExportingMetricReader({
        exporter: new OTLPMetricExporter({
            url:'http://collector:4318/v1/metrics'
        })
    })
    meterProvider.addMetricReader(metricReader);
    const meter = meterProvider.getMeter('my-service-meter');

    const traceExporter = new OTLPTraceExporter({
        url: 'http://collector:4318/v1/traces',
    });

    const sdk = new NodeSDK({
        traceExporter,
        serviceName: serviceName,
        instrumentations: [getNodeAutoInstrumentations({
            "@opentelemetry/instrumentation-fs":{
                enabled:false
            },
            "@opentelemetry/instrumentation-http":{
                headersToSpanAttributes:{
                    client:{
                        requestHeaders:['tracestate','traceparent','baggage']
                    },
                    server:{
                        requestHeaders:['tracestate','traceparent','baggage']
                    }
                }
            }
        })],
        autoDetectResources:true,
        resource: new Resource({
            'team.owner':'core-team',
            'deployment':'4'
        }),
        sampler: new ParentBasedSampler({
            root: new OurSampler()
        }),
        textMapPropagator: new CompositePropagator({
            propagators:[new W3CTraceContextPropagator(), new W3CBaggagePropagator()]
        })

    });

    sdk.start();

    return meter;
}

export default start