GrayGelf

GrayLog2 GELF UDP logging, streaming, chunking, and more. Production tested. Includes client and server implementations. AFAIK a complete GELF implementation.

Install

npm install graygelf

Example

var log = require('graygelf')('graylog.server.local')
log.on('message', console.log) // output messages to console

// setup global custom fields to be passed with every message
log.fields.facility = 'redicomps'

// printf style "hello world"
log.info('hello %s', 'world')

// concat by space style "hello world"
log.info('hello', 'world')

// stays context aware
redis.on('error', log.error)

// include a full message and custom fields using .a(ttach)
log.info.a('short', 'full', { foo: 'bar' })
log.info.a('short', 'full', { foo: 'bar' })

// if an Error is passed as the only argument...
var er = new Error('oh no!')
log.info(er)
// ... it expands to:
log.info.a(er.message, er.stack)

// writable streams can be created
var infostream = log.stream('info')
var rstream = require('fs').createReadStream(__filename)
rstream.pipe(infostream) // lines automatically split up and sent seperately

// raw gelf: version, host, and timestamp will be supplied if missing
log.raw({
  // version: '1.1',
  // host: 'wavded',
  short_message: 'oh no!',
  full_message: 'howdy',
  // timestamp: 1412087767.704356,
  level: 6,
  _foo: 'bar'
})

Setup

By host string (uses defaults below for other options):

var log = require('graygelf')('graylog.server.local')

By options object:

var log = require('graygelf'){{
  host: 'graylog.server.local',
  port: 23923
})

Available options are:

host
  - graylog host (default: 'localhost')
port
  - graylog port (default: 12201)
chunkSize
  - size of chunked messages in bytes (default: 1240)
compressType
  - compression 'gzip' or 'deflate' (default: 'deflate')
mock
  - don't send messages to GrayLog2 (default: false)

API

event: error

Emits errors that may occur while parsing and sending GELF messages.

event: message

Emits GELF JSON messages that will be send over UDP. Useful for redirecting output to stdout in development.

log.on('message', function (gelf) {
  console.log(gelf.level, gelf.short_message, gelf.long_message)
})

log.fields

Add global custom fields to be included in every message. Custom fields allow you to more interesting searches and sorting inside GrayLog2 servers.

log.fields.facility = 'facility'

Note: fields is plain JavaScript object.

log{level}(message)

GrayGelf maps the syslog levels to functions. All functions have the same semantics as console.log (i.e. printf style):

log.emerg('oh %s', 's*#t')              // 0 - alias: panic
log.alert('act', 'immediately')         // 1
log.crit('act %j', [ 'really soon' ])   // 2
log.error('expected %d, got %d', 1, 5)  // 3 - alias: err
log.warn('take note, it may bite')      // 4 - alias: warning
log.notice('unusual %s', 'behavior')    // 5
log.info('hello', 'world')              // 6
log.debug('value is', a)                // 7

log{level}.a(short, long, custom)

There also is an a(ttach) method to include a full message.

log.crit.a('short message', 'full message')

The a(ttach) method can have an optional third argument to define custom fields that will be passed to Graylog2.

log.info.a('short message', 'full message', { custom: 'field' })

log.stream(level)

Create a writable stream to pipe log messages into:

var stream = log.stream('info')

Streams automatically break lines up and pass each line to GrayLog2 at the specified level.

log.raw(gelf)

Pass a raw GELF message. The following fields will be populated if absent: version, host, and timestamp.

log.raw({
  version: '1.1',
  host: 'wavded',
  short_message: 'oh no!',
  full_message: 'howdy',
  timestamp: 1412087767.704356,
  level: 6,
  _foo: 'custom field'
})

Note: No global custom fields (log.fields) are included when using log.raw.

Server

Make your own GrayLog UDP server or proxy messages to GrayLog. A GrayGelf server handles zlib, gzip and GELF chunked messages.

Example

var gelfserver = require('graygelf/server')
var server = gelfserver()
server.on('message', function (gelf) {
  // handle parsed gelf json
  console.log('received message', gelf.short_message)
})
server.listen(12201)

event: message

Emits parsed GELF JSON messages.

event: data

Emits raw GELF buffers (useful for proxying).

event: error

Emits errors captured from udp or parsing.

server.listen(port = 12201, address = "0.0.0.0")

Start listening on a port and bind address. Both parameters are optional. Defaults to typical GrayLog2 server defaults.

server.close()

Close down a server and stop receiving messages.

server.unref()

Allow the Node process to terminate if the server is the only thing keeping it alive.

server.pipe(client)

var server = require('graygelf/server')().listen()
var client = require('graygelf')('proxy-dest.graylog.local')

server.pipe(client) // establish proxy (straight UDP transfer)

License

(The MIT License)

Copyright (c) 2014 Marc Harter [email protected]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.