Adding functionality to save logs to mongodb

[emech-en]

I think this would be good if add ability to save logs on mongodb

[dougwilson]

No, I'm sorry. This library is made to be generic. In fact, looking at your code, you can do exactly what you want with zero modifications to morgan: just pass in a stream that feeds into your mongodb.

[emech-en]

You'r right 👍

[dougwilson]

So this was my stab in the dark at it, following what was in your PR, but without bothering with the debug stuff. Hopefully this helps you out :)

var carrier = require('carrier')
var mongodb = require('mongodb')
var morgan = require('morgan')
var stream = require('stream')

var MongoClient = mongodb.MongoClient
var PassThroughStream = stream.PassThrough

module.exports = mongoMorgan

function mongoMorgan(format, mongodbUrl, options) {
  options = options || {}

  var buffer = []
  var collection = options.collection || 'request'

  // create stream for morgan to write to
  var stream = new PassThroughStream()

  // create stream to read from
  var lineStream = carrier.carry(stream)
  lineStream.on('line', onLine)

  // create mongo client
  var mongoCollection = null
  MongoClient.connect(mongodbUrl, onConnect)

  // mixin options
  options.stream = stream

  function onConnect(error, mongoDb) {
    if (error) {
      throw error
    }

    mongoCollection = mongoDb.collection(collection)
  }

  function onLine(line) {
    var entry = {
      time: Date.now(),
      request: line
    }

    buffer.push(entry)

    if (!mongoCollection) {
      return
    }

    while (buffer.length !== 0) {
      entry = buffer.shift()
      mongoCollection.insert(entry)
    }
  }

  return morgan(format, options)
}

[emech-en]

That's awesome :)
But isn't it bad to keep the db connection open during the program?
Thank you

[dougwilson]

No, it's a server, you want to keep the connection open. Otherwise you are opening and closing a connection for every single request. Think you you had 500 req/s what it would do to your MongoDB.