elastic-apm-node/lib/opentelemetry-bridge/setup.js

The official Elastic APM agent for Node.js

/*
 * Copyright Elasticsearch B.V. and other contributors where applicable.
 * Licensed under the BSD 2-Clause License; you may not use this file except in
 * compliance with the BSD 2-Clause License.
 */

'use strict';

const util = require('util');
const otel = require('@opentelemetry/api');

const logging = require('../logging');
const { fetchSpanKey } = require('./OTelBridgeRunContext');
const oblog = require('./oblog');
const { OTelContextManager } = require('./OTelContextManager');
const { OTelTracerProvider } = require('./OTelTracerProvider');
const { OTelTracer } = require('./OTelTracer');

function setupOTelBridge(agent) {
  let success;

  const log = logging.isLoggerCustom(agent.logger)
    ? agent.logger
    : agent.logger.child({ 'event.module': 'otelbridge' });

  // `otel.diag` is "the OpenTelemetry internal diagnostic API". If *trace*
  // level logging is enabled, then hook into diag.
  if (log.isLevelEnabled('trace')) {
    success = otel.diag.setLogger(
      {
        verbose: log.trace.bind(log),
        debug: log.debug.bind(log),
        info: log.info.bind(log),
        warn: log.warn.bind(log),
        error: log.error.bind(log),
      },
      otel.DiagLogLevel.ALL,
    );
    if (!success) {
      log.error('could not register OpenTelemetry bridge diag logger');
      return;
    }
  }

  // For development/debugging-only, set `LOG_OTEL_API_CALLS = true` to get log
  // (almost) every call into the OpenTelemetry API. See docs in "oblog.js".
  const LOG_OTEL_API_CALLS = false;
  if (LOG_OTEL_API_CALLS) {
    // oblog.setApiCallLogFn(log.debug.bind(log)) // Alternative, to use our ecs logger.
    oblog.setApiCallLogFn((...args) => {
      const s = util.format(...args);
      console.log('\x1b[90motelapi:\x1b[39m \x1b[32m' + s + '\x1b[39m');
    });
  }

  success = otel.trace.setGlobalTracerProvider(
    new OTelTracerProvider(new OTelTracer(agent)),
  );
  if (!success) {
    log.error('could not register OpenTelemetry bridge TracerProvider');
    return;
  }

  // The OTelBridgeRunContext class needs to get the SPAN_KEY before it can
  // be used.
  fetchSpanKey();

  success = otel.context.setGlobalContextManager(new OTelContextManager(agent));
  if (!success) {
    log.error('could not register OpenTelemetry bridge ContextManager');
  }
}

module.exports = {
  setupOTelBridge,
};