Bala-raj/gcp-nodejs-correlate-logs

Helper module for nodejs applications to correlate logs in Google Cloud Platform

With Google's solution has limitation which let you use only wherever you have access to the request object - https://github.com/googleapis/nodejs-logging-bunyan

But with this you can log anywhere.

Step 1:

You need to enable in GCP and use in your application -> @google-cloud/trace-agent

Step 2:

This example shown below will push logs only when it is production or staging server.

For dev also using the bunyan logger but this way it saves a cost instead pushing unnecessary local logs to cloud.

config/logger.js

import { LoggingBunyan } from '@google-cloud/logging-bunyan';
import createLogger from 'gcp-nodejs-correlate-logs';

import { getProjectId, ifDev } from './config';

// Creates a Bunyan Stackdriver Logging client
const loggingBunyan = new LoggingBunyan();

let loggerOption;

if (ifDev()) {
  const bunyanDebugStream = require('bunyan-debug-stream'); // eslint-disable-line
  loggerOption = {
    name: 'rocket-science',
    streams: [{
      level: 'info',
      type: 'raw',
      stream: bunyanDebugStream({
        forceColor: true,
      }),
    }],
    serializers: bunyanDebugStream.serializers,
  };
} else {
  loggerOption = {
    name: 'rocket-science',
    level: 'info',
    streams: [loggingBunyan.stream('info')],
  };
}


const { loggerContextMiddleware, log } = createLogger(getProjectId() || 'dev', loggerOption);

export { loggerContextMiddleware, log };

server.js

import express from 'express';

// Activate Google Cloud Trace before logging
if (ifLive() || ifStaging())
  require('@google-cloud/trace-agent').start(); 

import config, { APPLICATION_MODE } from './config/config';
import { loggerContextMiddleware, log } from './config/logger';

const app = express();

app.use(loggerContextMiddleware); // Should add this middleware for correlating the logs.

app.listen(config.PORT, () => log.info(`Server listening on port ${config.PORT}... Application Mode: ${APPLICATION_MODE}`));

Import the log and use it wherever you want.

api.js

import { Router }  from 'express';

import { log } from './config/logger';

const route = Router();

route.use('/', ( req, res) => { 
  log.info('Seems working');
  res.send('Hello!')
});