Learn about our RFC process, Open RFC meetings & more.Join in the discussion! »

This package has been deprecated

Author message:

WARNING: This project has been renamed to 'koa-access'. Install using [email protected] instead

@uswitch/koa-logger

1.1.0 • Public • Published

Koa Logger

A Koa middleware for creating consistent, per-request access logs for your requests.

Overview | Usage | Api | Contributors

Contributors License type language test style

Overview

This package is a Koa middleware inspired by Morgan, an access log middleware for Express.

It tries to address the following;

  • 🖌 Custom formatting - Allow you to inject your own formatting
  • 💰 Custom tokens - Allow you to add your own extra logging tokens
  • 📓 JSON tokens - All of this is handled using JSON rather than strings

All of this allows you to create consistent access logs decoupled from the actual implementation of your code.


Usage

import Koa from 'koa'
import logger from 'koa-logger'
 
const app = new Koa()
 
app.use(logger())           /* Default configuration */
app.use(logger([ 'id' ]))   /* Add `id` from `ctx.state` to access log */
 
app.use(logger(readContext)) /* Read extra poperties by calling `readContext` on `ctx` */
 
app.on('koa-logger:access', Logger.log)

This package uses Event Emitters to decouple the handling of logging from the implementation of your code.

API

By default, the koa-logger will bundle the following properties into an object and fire them on the the koa-logger:access event.

{
  "res": {
    "responseTime": 23    // Response time in `ms`
    "length": 23232       // Content length of the response
    "status": 200         // Response status
    "time": "2017-..."    // Timestamp of the response
  },
  "req": {
    "method": "GET"       // Method of request
    "path": "/foo/bar"    // Path being accessed
    "time": "2017-..."    // Timestamp of request start
    "host": "127.0.0.1"   // Host of the request
  }
}

The koa-logger can be configured with extra parameters in one of two ways,

Array - logger([ 'id', 'errors' ])

This will add the id and errors properties from the Koa ctx.state object onto the access log object.

Function - logger((ctx) => ({ id: ctx.state.id, errors: ctx.state.errors }))

This will return an object by calling the function on Koa's ctx object, in this example, it'll just grab the id and errors properties from the state.

Events

Once a request access log has been built, the following event is fired with the access object

koa-logger:access => (ctx, { req, res, ...extras })

The event can be imported from the koa-logger module, as

import { eventAccess } from 'koa-logger'

Contributors

Thanks goes to these wonderful people (emoji key):


Dom Charlesworth

📖 💻 🤔 🔌

David Annez

💻 🤔 🔌

This project follows the all-contributors specification. Contributions of any kind welcome!

Keywords

none

Install

npm i @uswitch/koa-logger

DownloadsWeekly Downloads

1

Version

1.1.0

License

MIT

Last publish

Collaborators

  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar
  • avatar