crummy

Crummy

A logger's bus. Also an adjective meaning "no good" or "undesirable"

- http://pacificforestfoundation.org/glossary.html

crummy is middleware to simply attach a bunyan logger to the request context of your http server of choice. Below is a list of supported http server modules:

• express
• koa

If you don't see yours above, feel free to request it in the issues section of this repository, or use the adapter module to adapt it to your own.

The reason bunyan is required is because it is the one popular logging module that I could find that made it really easy to make a copy of a logger with all of the different logging transports that the original had. If winston or other loggers support this, I would be willing to support multiple logging modules.

Usage with express

const express = require('express')
const crummy = require('crummy/express')
const uuid = require('uuid')
const log = require('./lib/log')

const app = express()

app.use(crummy({
  path: 'log', // will attach to `req.log`
  logger: log, // The bunyan logger to use. `.child()` will be called on it
  meta: (req, res) => { // attaches returned object to metadata of each log in the request
    return {
      reqId: return uuid.v4()
    }
  }
}))
app.use((req, res, next) => {
  req.log.info(req.method, req.path) // Will log the path requested, as well as any default meta data
})

// ... routes, other middleware, app.listen(), etc.

Usage with koa

const koa = require('koa')
const crummy = require('crummy/koa')
const uuid = require('uuid')
const log = require('./lib/log')

const app = koa()

app.use(crummy({
  path: 'log', // will attach to `req.log`
  logger: log, // The bunyan logger to use. `.child()` will be called on it
  meta: (req, res) => { // attaches returned object to metadata of each log in the request
    return {
      reqId: return uuid.v4()
    }
  }
}))
app.use(function *(next) {
  this.log.info(req.method, req.path);
  let start = Date.now()
  yield next
  let responseTime = Date.now() - start
  this.log.info(`${responseTime}ms`)
})

// ... other koa setup stuff

Usage on your own

This really isn't a lot of code. It just has some sensible defaults. The core piece of this module might make more sense if there were different adapters to utilize. Below is an example of what this module is doing without actually using this module:

const express = require('express')
const uuid = require('uuid')
const log = require('./lib/log')

const app = express()

app.use((req, res, next) => {
  req.log = log.child({ reqId: uuid.v4() })
  next()
})

app.use((req, res, next) => {
  req.log.info(req.method, res.path)
})

// ... routes, other middleware, app.listen(), etc.

After reading that, you will probably just opt to just roll your own, which is totally fine. I wrote this because I don't like to have any miscellaneous modules lying around. I like most of my middleware stack to be declarative. For what it's worth, there are tests around the functionality described above, which might be a bit overkill.