bunyan-streams-config

Create bunyan streams from JSON configuration


Keywords
bunyan, logging, log, json
License
MIT
Install
npm install bunyan-streams-config@1.0.2

Documentation

Bunyan Streams Config

This package provides a function which creates a bunyan streams configuration from a simple JSON, i.e. one which can easily be exposed in a configuration file and set by the end user without having to worry about technical details of bunyan or node.

Example

In a config file:

"log": [
  {
    "type": "console-pretty",
    "level": "debug"
  },
  {
    "type": "file",
    "path": "app.log"
  }
]

in application:

const bunyan = require('bunyan');
const bunyanStreamsConfig = require('bunyan-streams-config');
const config = // Load JSON config

const log = bunyan.createLogger({
  name: 'my-app',
  streams: bunyanStreamsConfig(config.log)
});

log.error("D'oh!");

would create two streams, one directed to the console (pretty-printed), the other to a file.

bunyan-streams-config is similar to bunyan-config, but with a few differences:

  • you can add custom stream types as a second argument to bunyanStreamsConfig

  • bunyan type of the stream is not exposed to the user (raw or other)

  • serializers are not exposed to the user

  • bunyan-streams-config provides 4 pre-defined stream types: console, console-pretty, file, file-pretty

Install

npm install bunyan-streams-config

API

bunyanStreamsConfig(streams, options)

Create bunyan streams from JSON configuration.

  • streams (Array): Array of streams, where stream is an object:

    • type: Stream type. One of pre-defined types (see below) or one in options.streamTypes.

    • other: Options passed to the stream type function.

  • options (Object): Options:

    • streamTypes (Object): Custom stream types, where key is the stream type name and value is a function which creates the stream.

    • defaults (Object): Default properties passed to stream type functions.

The function throws an error if any stream type in streams is invalid.

Pre-defined Stream Types

console

Console/stderr stream (bunyan JSON objects).

console-pretty

Console/stderr stream (pretty-printed with bunyan-prettystream).

file

File stream (bunyan JSON objects). Options:

  • path: Log file path.

file-pretty

File stream (pretty-printed with bunyan-prettystream). Options:

  • path: Log file path.

Custom Stream Types

Custom stream types can be supported by supplying a function which creates a bunyan stream.

Example:

log-file.js:

'use strict';

const _ = require('lodash');

module.exports = function createStream(options) {
  return _.defaults({
    stream: process.stderr
  }, options);
};

in application:

const log = bunyan.createLogger({
  name: 'my-app',
  streams: bunyanStreamsConfig(config.log, {
    streamTypes: {
      'file': require('log-file.js')
    }
  })
});

Some bunyan packages are suitable to be passed in streamTypes as is, e.g.:

const log = bunyan.createLogger({
  name: 'my-app',
  streams: bunyanStreamsConfig(config.log, {
    streamTypes: {
      'seq': require('bunyan-seq').createStream
    }
  })
});

for logging to Seq. The output of the function should be an object normally passed to bunyan.createLogger as an item of the streams array.

License

Bunyan Streams Config is provided under the terms of the MIT license (see LICENSE.md).