Opinionated Logging for NodeJS

Setting up logging that is useful and flexible, for both development and production, seems hard.

This is an opinionated approach, with sane defaults, for servers (HTTP or otherwise) written in NodeJS.

Principles and Settings

• Use console.log as you wish in development, but (by default) suppress its output in production (NODE_ENV === 'production').
• In order to see console.log output in production, set WINSTON_LEVEL to debug (which will also enable all winston based logger.debug() logs).
• log output in production is into ./app-%date%.log, no output on the console itself.
• Log output, when not in production, is to the console, nothing written to files.
• In production, an additional file error-%date%.log is written with actual errors.
• Files written are limited in size and rotated.
• Files older than 14 days are removed.

Install

Via npm

npm install --save u5-nodejs-logging

... or via yarn

yarn add u5-nodejs-logging

Logging via Winston

const { logger } = require('u5-nodejs-logging')

...
logger.info('successfully saved')
...

Request Logging and Error Handling for ExpressJS

const {
  expressLoggingMiddleware, expressErrorHandlingMiddleware
} = require('u5-nodejs-logging')

const app = express()

app.use(expressLoggingMiddleware()) // first middleware
// ... routes etc here, via app.get() etc.
app.use(expressErrorHandlingMiddleware()) // last middleware
app.listen(process.env.PORT || 3000)