client.js

'use strict';

const http = require('http');
const opentracing = require('opentracing');
const shim = require('./shim').shim('http_client_opentracing');

opentracing.initGlobalTracer(shim);
const tracer = opentracing.globalTracer();

makeRequest();

async function makeRequest() {
  const span = tracer.startSpan('make_request');

  const headers = {};
  tracer.inject(span, opentracing.FORMAT_HTTP_HEADERS, headers);

  http
    .get(
      {
        host: 'localhost',
        port: 3000,
        path: '/',
        headers,
      },
      (resp) => {
        let data = '';

        resp.on('data', (chunk) => {
          data += chunk;
        });

        resp.on('end', async () => {
          console.log(JSON.parse(data));
          span.finish();

          console.log('Sleeping 5 seconds before shutdown to ensure all records are flushed.');
          setTimeout(() => { console.log('Completed.'); }, 5000);
        });
      },
    )
    .on('error', (err) => {
      console.log(`Error: ${err.message}`);
    });
}