Extracting trace from header and sending to Logs for correlation

bunyan.js

const express = require('express');
const app = express();

const bunyan = require('bunyan');
const {LoggingBunyan} = require('@google-cloud/logging-bunyan');

const loggingBunyan = new LoggingBunyan();

const project = 'steren-test';

const logger = bunyan.createLogger({
  name: 'app',
  level: 'info',
  streams: [
    {stream: process.stdout},
    loggingBunyan.stream(),
  ],
});

app.get('/', (req, res) => {
  const traceHeader = req && req.headers ? req.headers['x-cloud-trace-context'] || '' : '';
  const traceId = traceHeader ? traceHeader.split('/')[0] : '';

  logger.info(`traceid: ${traceId}`);

  logger.info({
    'logging.googleapis.com/trace': `projects/${project}/traces/${traceId}`
  }, 'good trace?');

  res.send('Bunyan');
});

const server = app.listen(process.env.PORT || 8080, () => {
  const host = server.address().address;
  const port = server.address().port;

  console.log(`Example app listening at http://${host}:${port}`);
});