Simple Logger

Usage Example

const { Logger } = require('hearth-logger')

const logger = new Logger({
  name: 'Job Name',
  type: 'Job Type',
})

// To log start time, will be required to calculate the execution time of the process
logger.startLogTime()

/*
  ..... Your Code
*/

// Utility methods to log messages at different levels
logger.info('Some Information')
logger.warn('Some Warning')
logger.error('Some Error')

// To log custom values into the job information
logger.jobConfig.set('KEY', 'VALUE')

// Utility method to log the statusCode of the process
logger.setJobStatus(200)
logger.setJobStatus(202)

// log the end time of the process, will be required to calculate the execution time of the process
logger.endLogTime()

// Save Logs to a temporary .log file, inside tmp folder in the root of your project
logger.save()
// Calling save in succession merges the logs into one file, see below if you want to save in a new log file
logger.save()
// Save Logs to a new temporary .log file, inside tmp folder in the root of your project
logger.save({saveAsNew: true})

info(message, options), warning(message, options) and error(message, options)

message: any

options: object

1. hoisted (boolean): Hoisted logs always appear on top on the normal logs. Can be used to highlight some important logs.

save(options)

Options: object

1. saveAsNew: Save the logs to a new log file with a new timestamp, instead of overwriting the regular log file
2. clearLogsOnSave: The stored logs will be cleared after save and will not appear in subsequent calls to the save() method.

Samples

Code

const { Logger } = require('hearth-logger')

const JobInfo = {
  name: 'Website Name',
  type: 'Scrapper',
}

const logger = new Logger(JobInfo, {
  removeLogFileOnSave: false,
})

// Updating the logger info after initialization
logger.updateConfig(
  {
    name: 'ABC.COM Scrapper',
    type: 'Scraper',
    description: 'Web scraper for https://abc.com',
  },
  {
    debugLevel: 2,
  }
)

logger.startLogTime()

logger.info('Started Scrapping')

// Simulate scrapping delay
for (let i = 0; i < 10000000000; i++) {}

logger.error('Some error')
logger.warn('Some warning')
logger.setJobStatus(400)

// Setting custom job information
logger.jobInfo.set('NEW ENTITIES SCRAPPED', 0)

logger.endLogTime()
logger.save()

Log File

===========================================
JOB INFORMATION
===========================================
NAME : Website Scrapper
TYPE : Scrapper
STATUS_CODE : 400
NEW ENTITIES SCRAPPED : 0
STARTED AT : 15-05-2020 | 09:06:54
FINISHED AT : 15-05-2020 | 09:07:03
EXECUTION TIME : 0 hrs 0 min 8 sec 567 ms

===========================================
LOGS
===========================================
[INFO] | 09:06:54 	Started Scrapping

[ERROR] | 09:07:03 	Some error

[WARNING] | 09:07:03 	Some warning

Using Adapters

Uploading logs to Amazon S3

For uploading your logs to S3, you can use the provided S3 adapter. This adapter uses aws-sdk behind the scenes, hence you can use the authentication options provided by the aws-sdk. Here is a code sample:-

import { Logger, S3Adapter } from './src'
import { JobInfo, JobType } from './src/interfaces'

async function main() {
  const jobInfo: JobInfo = {
    name: 'Idealista Scrapper',
    type: JobType.Scrapper,
  }

  const logger = new Logger(jobInfo, {
    removeLogFileOnSave: true,
  })

  const s3Plugin = new S3Adapter(
    {
      bucketName: 'BUCKET_NAME',
    },
    {
      /* AWS-SDK S3 CONFIG */
    },
  )

  // Tell the logger to use the s3 adapter
  logger.useAdapter(s3Plugin)

  logger.startLogTime()
  logger.info('Started Scrapping')

  // Simulate process delay
  for (let i = 0; i < 10000000000; i++) {}

  logger.setJobStatus(200)

  // Setting custom job information
  logger.jobInfo.set('NEW PROPERTIES ADDED', 123)

  logger.endLogTime()

  // When you call this method, the log file will be uploaded to the s3 bucket with
  // the name 'BUCKET_NAME", on the path Logs/Transformer
  await logger.save()
}
main()