@apolitical/server/src/loaders/otel.loader.js

Node.js module to encapsulate Apolitical's express server setup

'use strict';

const { NodeSDK } = require('@opentelemetry/sdk-node');
const { OTLPTraceExporter } = require('@opentelemetry/exporter-trace-otlp-grpc');
const { getNodeAutoInstrumentations } = require('@opentelemetry/auto-instrumentations-node');
const { resourceFromAttributes } = require('@opentelemetry/resources');
const { ATTR_SERVICE_NAME } = require('@opentelemetry/semantic-conventions');

module.exports = ({ logger }) => {
  return async function load() {
    const otlpHost = process.env.OPENTELEMETRY_COLLECTOR_SERVICE_HOST;
    const otlpPort = process.env.OPENTELEMETRY_COLLECTOR_SERVICE_PORT;
    if (!otlpHost || !otlpPort) {
      return;
    }
    const oltpEndpoint = `http://${otlpHost}:${otlpPort}`;
    const serviceName = process.env.CONTAINER_NAME || 'unknown-v1-service';
    const sdk = new NodeSDK({
      resource: resourceFromAttributes({
        [ATTR_SERVICE_NAME]: serviceName,
      }),
      traceExporter: new OTLPTraceExporter({ url: oltpEndpoint }),
      instrumentations: [getNodeAutoInstrumentations()],
    });
    sdk.start();
    const log = logger.where(__filename, 'load');
    log.info(`OpenTelemetry SDK started with service name ${serviceName} and endpoint ${oltpEndpoint}`);

    process.on('SIGTERM', async () => {
      await sdk.shutdown();
      process.exit(0);
    });
  };
};