gelf-pro

node-gelf pro

node-gelf - Graylog2 client library for Node.js. Pro - because of code-quality. GELF - The Graylog Extended Log Format.

Installation

"dependencies": {
  "gelf-pro": "~1.0" // see the "releases" section
}

npm install gelf-pro

Initialization

var log = require('gelf-pro');

Configuration

// simple
log.setConfig({host: 'my.glog-server.net'});

// advanced
log.setConfig({
  fields: {facility: "example", owner: "Tom (a cat)"}, // optional; default fields for all messages
  filter: [], // optional; filters to discard a message
  transform: [], // optional; transformers for a message
  broadcast: [], // optional; listeners of a message
  levels: {}, // optional; default: see the levels section below
  adapterName: 'udp', // optional; currently supported "udp" and "tcp"; default: udp
  adapterOptions: {
    protocol: 'udp4', // udp only; optional; udp adapter: udp4, udp6; default: udp4
    family: 4, // tcp only; optional; version of IP stack; default: 4
    timeout: 1000, // tcp only; optional; default: 10000 (10 sec)
    host: '127.0.0.1', // optional; default: 127.0.0.1
    port: 12201 // optional; default: 12201
  }
});

Basic functionality

var extra = {tom: 'cat', jerry: 'mouse', others: {spike: 1, tyke: 1}};

log.info("Hello world", extra, function (err, bytesSent) {});
log.info("Hello world", function (err, bytesSent) {});
log.info("Hello world", extra);
log.info("Hello world");

log.error('Oooops.', new Error('An error message'));
log.error(new Error('An error message'));

log.message(new Error('An error message'), 3); // same as previous

Extra

In case extra is a plain object, the library converts it to a readable format. Other values are converted to string. Acceptable format of a key is: ^[\w-]$

log.info(
  'a new msg goes here',
  {me: {fname: 'k', lname: 'k', bdate: new Date(2000, 01, 01)}}
);
// the extra becomes:
// {_me_fname: 'k', _me_lname: 'k', _me_bdate: 'Tue Feb 01 2000 00:00:00 GMT+0100 (CET)'}

Filtering

Sometimes we have to discard a message which is not suitable for the current environment. It is NOT possible to modify the data.

log.setConfig({
  filter: [
    function (message) { // rejects a "debug" message
      return (message.level < 7);
    }
  ]
});

Transforming

transforming happens after filtering. It is possible to modify the data.

log.setConfig({
  transform: [
    function (message) { // unwind an error
      if (_.isError(message.error)) {
        message.error = {message: message.error.message, stack: message.error.stack};
      }
      return message;
    }
  ]
});

Broadcasting

broadcasting happens after transforming. It is NOT possible to modify the data.

log.setConfig({
  broadcast: [
    function (message) { // broadcasting to console
      console[message.level > 3 ? 'log' : 'error'](message.short_message, message);
    }
  ]
});

Levels (1, 2, 3)

emergency, alert, critical, error, warning (warn), notice, info, debug (log)

Adapters

• UDP (with deflation and chunking)
• TCP

Tests

Cli

npm install
npm test

Docker

[sudo] docker build --no-cache -t node-gelf-pro .
[sudo] docker run -ti --rm -v "${PWD}:/opt/app" -w "/opt/app" node-gelf-pro

Contributors

• corbinu
• jucrouzet

License

The MIT License (MIT)

Copyright (c) 2013-2016 Kanstantsin Kamkou