pino-datadog/src/streams.js

A transport for pino that sends messages to DataDog

'use strict'

const batch2 = require('batch2')
const split2 = require('split2')
const through2 = require('through2')
const fastJsonParse = require('fast-json-parse')

function batchStream (size) {
  return batch2.obj({ size })
}

function parseJsonStream () {
  return split2(function (str) {
    const result = fastJsonParse(str)
    if (result.err) return
    return result.value
  })
}

function levelToStatus (level) {
  if (level === 10 || level === 20) { return 'debug' }
  if (level === 40) { return 'warning' }
  if (level === 50) { return 'error' }
  if (level >= 60) { return 'critical' }
  return 'info'
}

function toLogEntry (item) {
  const timestamp = item.time || new Date().getTime()
  const status = levelToStatus(item.level)
  const message = item.msg || status
  const host = item.hostname || ''
  const service = item.service || ''
  const ddsource = item.ddsource || item.source || ''
  const objTags = (item.labels || item.tags || {})
  const ddtags = Object.keys(objTags).map(k => { return `${k}:${objTags[k]}` }).join(',')

  const entry = Object.assign({}, item, { timestamp, status, message, host, service, ddsource, ddtags })
  delete entry.time; delete entry.level; delete entry.hostname; delete entry.source; delete entry.labels; delete entry.tags
  if (!service) { delete entry.service }
  if (!ddsource) { delete entry.ddsource }
  if (!ddtags) { delete entry.ddtags }
  return entry
}

function toLogEntryStream (options = {}) {
  return through2.obj(function transport (chunk, enc, cb) {
    const entry = toLogEntry(chunk)
    if (!options.keepMsg) {
      delete entry.msg
    }
    cb(null, entry)
  })
}

module.exports = {
  batchStream,
  parseJsonStream,
  toLogEntryStream
}