index.js

'use strict';

var extend = require('extend');
var path = require('path');
var objectPath = require('object-path');

module.exports = convertConfig;

var streamConverters = {
  stdout: function () {
    return process.stdout;
  },

  stderr: function () {
    return process.stderr;
  },

  'bunyan-logstash': function (params) {
    return require('bunyan-logstash').createStream(params);
  },

  'bunyan-redis': function (params) {
    return new (require('bunyan-redis'))(params);
  },

  'bunyan-logentries': function (params) {
    return require('bunyan-logentries').createStream(params);
  }
};

/**
 * Converts jsonConfig into proper bunyan config. The original object is not modified.
 *
 * @param {Object} jsonConfig
 * @returns {Object} bunyanConfig
 */
function convertConfig(jsonConfig) {
  var bunyanConfig = extend({}, jsonConfig);

  if (Array.isArray(bunyanConfig.streams)) {
    bunyanConfig.streams = bunyanConfig.streams.map(convertStream);
  }

  if (bunyanConfig.serializers) {
    bunyanConfig.serializers = convertSerializers(bunyanConfig.serializers);
  }

  return bunyanConfig;
}

function convertStream(stream) {
  var converter = streamConverters[getStreamName(stream)];

  return typeof converter === 'function' ? extend({}, stream, {
    stream: converter(getStreamParams(stream))
  }) : stream;
}

function getStreamName(stream) {
  if (!stream || !stream.stream) {
    return '';
  } else if (typeof stream.stream === 'string') {
    return stream.stream;
  } else if (typeof stream.stream.name === 'string') {
    return stream.stream.name;
  }
}

function getStreamParams(stream) {
  return stream && stream.stream && stream.stream.params;
}

function convertSerializers(serializers) {
  if (typeof serializers === 'string') {
    return convertSerializer(serializers);

  } else if (typeof serializers === 'object' && serializers !== null) {
    var convertedSerializers = {};
    for (var key in serializers) {
      convertedSerializers[key] = convertSerializer(serializers[key]);
    }
    return convertedSerializers;
  } else {
    return serializers;
  }
}

function convertSerializer(serializer) {
  if (typeof serializer !== 'string' || serializer === '') {
    return serializer;
  }

  var serializerParts = serializer.split(':');
  if (serializerParts.length > 2 || serializerParts[0] === '') {
    return serializer;
  }

  var serializerModuleId = serializerParts[0][0] === '.' ? path.resolve(serializerParts[0]) : serializerParts[0];
  var serializerModule = require(serializerModuleId);

  var serializerProperty = serializerParts[1] || '';
  if (serializerProperty) {
    return objectPath.get(serializerModule, serializerProperty);
  } else {
    return serializerModule;
  }
}