LOGGING.md

Logging

One of Dr Queue's aims, is to help organize and aggregate logs for Koa using Redis. Dr Queue piggybacks on an already popular transport module for logging called Winston. (See Winston)

Dr Queue installs and uses Winston ^3.21. Dr Queue initializes Winston for you and adds some basic color formatting. Each log statement that Dr Queue writes, assumes that this app might be part of a bigger system where it can subscribe to specific Redis channels to receive real time log events, if you want to ensure the log message is received you can use the the queue to manage acknowledging these logs messages and saving them to disk. See Pubsub

Dr. Queue uses the configuration module config to handle its configuration, however initializing of the LoggerUtil can just take an object.

Dr Queue requires Koa bodyParser middleware if you want to see the request body attributes in your log message.

Example: TL;DR

import {Logger as LoggerUtil} from 'dr_queue'
import Koa from 'koa'
import Router from 'koa-router'
import bodyParser from 'koa-bodyparser'

const config = require('config')
const Logger = require('../out/logger').default
const Koa = require('koa')
const Router = require('koa-router')
const bodyParser = require('koa-bodyparser')
const moment = require('moment')

const config = {
  hostIp : '127.0.0.1',
  appName: 'queue',
  timezone: 'America/Los_Angeles',
  hostname: 'localhost',
  errorIgnoreLevels: [401, 403],
  transports:[{
    filename: './info.log',
    format: 'txt'
    },{
      filename: './error.log',
      format: 'txt'
    }]
}


const dbs = {
  client: redisClient, // for the queue`
  publisher: redisPublisher, // for the stream`
}

const LoggerUtil = LoggerUtil.init(config, dbs)
export const Logger = LoggerUtil.init(config, dbs)

const app = new Koa()
app.use(bodyParser())
  .use(LoggerUtil.middleware(Logger))
  .use(router.allowedMethods())
  .use(router.routes())
  app.listen(port, () => Logger.log(`✅ The server is running at ${protocol}://${hostIp}:${port}/`), {meta: 'test'})
return app

Stripping sensitive information

Sometimes, you don't want to see certain errors show up in your log files because they are benign and fill up your logs, for instance, bad logins attempts. You can filter these errors out of the error log with the errorIgnoreLevels filters. These error ignore filters list exist in the configuration file.

Of course, I am sure you have heard about the time a company discovered they were logging out sensitive information in their log files, like passwords. To prevent this, Dr Queue middleware takes a list of keys to filter out these items. (See Middleware)

To See a simple working test, modify your publisher and subscriber connection in the /config/default.json script

In a console window, type:

CHANNEL=dev:queue npm run subscriber

Open another console window, type:

npm run test:grep Middleware