pino-http

High-speed HTTP logger for Node.js

To our knowledge, pino-http is the fastest HTTP logger in town.

Installation
Usage
Benchmarks
API
Team
Acknowledgements
License

Benchmarks

Benchmarks log each request/response pair while returning 'hello world', using autocannon with 100 connections and 10 pipelined requests.

http-ndjson (equivalent info): 7730.73 req/sec
http-ndjson (standard minimum info): 9522.37 req/sec
pino-http: 21496 req/sec
pino-http (extreme): 25770.91 req/sec
no logger: 46139.64 req/sec

All benchmarks where taken on a Macbook Pro 2013 (2.6GHZ i7, 16GB of RAM).

Install

npm i pino-http --save

Example

'use strict'

var http = require('http')
var server = http.createServer(handle)

var logger = require('pino-http')()

function handle (req, res) {
  logger(req, res)
  req.log.info('something else')
  res.end('hello world')
}

server.listen(3000)

$ node example.js | pino
[2016-03-31T16:53:21.079Z] INFO (46316 on MBP-di-Matteo): something else
    req: {
      "id": 1,
      "method": "GET",
      "url": "/",
      "headers": {
        "host": "localhost:3000",
        "user-agent": "curl/7.43.0",
        "accept": "*/*"
      },
      "remoteAddress": "::1",
      "remotePort": 64386
    }
[2016-03-31T16:53:21.087Z] INFO (46316 on MBP-di-Matteo): request completed
    res: {
      "statusCode": 200,
      "header": "HTTP/1.1 200 OK\r\nX-Powered-By: restify\r\nContent-Type: text/html; charset=utf-8\r\nContent-Length: 11\r\nETag: W/\"b-XrY7u+Ae7tCTyyK7j1rNww\"\r\nDate: Thu, 31 Mar 2016 16:53:21 GMT\r\nConnection: keep-alive\r\n\r\n"
    }
    responseTime: 10
    req: {
      "id": 1,
      "method": "GET",
      "url": "/",
      "headers": {
        "host": "localhost:3000",
        "user-agent": "curl/7.43.0",
        "accept": "*/*"
      },
      "remoteAddress": "::1",
      "remotePort": 64386
    }

API

pinoHttp([opts], [stream])

opts: it has all the options as pino and

logger: pino-http can reuse a pino instance if passed with the logger property
genReqId: you can pass a function which gets used to generate a request id. The first argument is the request itself. As fallback pino-http is just using an integer. This default might not be the desired behavior if you're running multiple instances of the app
useLevel: the logger level pino-http is using to log out the response. default: info
stream: same as the second parameter

stream: the destination stream. Could be passed in as an option too.

Examples

Logger options

'use strict'

var http = require('http')
var server = http.createServer(handle)
var pino = require('pino')()
var logger = require('pino-http')({
  // Reuse an existing logger instance
  logger: pino,

  // Define a custom request id function
  genReqId: function (req) { return req.id },

  // Define custom serializers
  serializers: {
    req: pino.stdSerializers.req,
    res: pino.stdSerializers.res
  },

  // Logger level is `info` by default
  useLevel: 'info'
})

function handle (req, res) {
  logger(req, res)
  req.log.info('something else')
  res.end('hello world')
}

server.listen(3000)

pinoHttp.startTime (Symbol)

The pinoHttp function has a property called startTime which contains a symbol that is used to attach and reference a start time on the HTTP res object. If the function returned from pinoHttp is not the first function to be called in an HTTP servers request listener function then the responseTime key in the log output will be offset by any processing that happens before a response is logged. This can be corrected by manually attaching the start time to the res object with the pinoHttp.startTime symbol, like so:

var http = require('http')
var logger = require('pino-http')()
var someImportantThingThatHasToBeFirst = require('some-important-thing')
http.createServer((req, res) => {
  res[logger.startTime] = Date.now()
  someImportantThingThatHasToBeFirst(req, res)
  logger(req, res)
  res.end('hello world')
}).listen(3000)

Default serializers

pinoHttp.stdSerializers.req

Generates a JSONifiable object from the HTTP request object passed to the createServer callback of Node's HTTP server.

It returns an object in the form:

{
  pid: 93535,
  hostname: 'your host',
  level: 30,
  msg: 'my request',
  time: '2016-03-07T12:21:48.766Z',
  v: 0,
  req: {
    id: 42,
    method: 'GET',
    url: '/',
    headers: {
      host: 'localhost:50201',
      connection: 'close'
    },
    remoteAddress: '::ffff:127.0.0.1',
    remotePort: 50202
  }
}

pinoHttp.stdSerializers.res

Generates a JSONifiable object from the HTTP response object passed to the createServer callback of Node's HTTP server.

It returns an object in the form:

{
  pid: 93581,
  hostname: 'myhost',
  level: 30,
  msg: 'my response',
  time: '2016-03-07T12:23:18.041Z',
  v: 0,
  res: {
    statusCode: 200,
    header: 'HTTP/1.1 200 OK\r\nDate: Mon, 07 Mar 2016 12:23:18 GMT\r\nConnection: close\r\nContent-Length: 5\r\n\r\n'
  }
}

Custom serializers

Each of the standard serializers can be extended by supplying a corresponding custom serializer. For example, let's assume the request object has custom properties attached to it, and that all of the custom properties are prefixed by foo. In order to show these properties, along with the standard serialized properties, in the resulting logs, we can supply a serializer like:

var http = require('http')
var logger = require('pino-http')({
  serializers: function (req) {
    Object.keys(req.raw).forEach((k) => {
      if (k.startsWith('foo')) {
        req[k] = req.raw[k]
      }
    })
    return req
  }
})