AC Logger

Unified logging function for all backend applications of AdmiralCloud. Use it instead of Winston (it is based on Winston)

The purpose of the little app is to make sure that all applications use the same log format/notations.

Usage

Use it like Winston!

const aclog = require('ac-logger')

const logConfig = {
  prefixFields: [
    { field: 'jobId', short: 'J' },
  ],
  applicationLogs: {
    enabled: true // if true, JSON formatted, machine readable application logs will be created into logs directory
  }
}

app = {} // 
app.log = aclog({ prefixFields: logConfig.prefixFields }).acLogger

// DEPRECATED
let logMeta = {
  fileName: 'UploadS3',
  functionName: 'upload',
  jobId: 123 // prefixField
}
app.log.info('Message for %s', 'some string', { meta: logMeta })
// -> INFO UploadS3 | upload | J 193 | Message for some string

// MODERN APPROACH (that is best suited for machine and human readability)
app.log.info('Message for some string', { functionName: 'upload', ... }) // all meta data like "functionName" will be available in application logs

Error logging

If you want to add the stack (from an error instance) to an error log use it like this:

try {
  let data = Buffer.from()
}
catch(e) {
  app.log.error('We have encountered an error in module %s', 'Module name', { e })
}

This will result in a nice log entry and above that a console.error message with the stack from e.

If you want to log a custom error message, not an error instance, you can use it like this:

let errorMessage = {
  message: 'user_emailWrong',
  code: 1234
}
app.log.error('We have encountered an error in module %s - %j', 'Module name', errorMessage)

// -> We have encountered an error in module Module name - { message: 'user_emailWrong', code: 1234 }

#Helper functions To improve the logging even more, there are several helper functions available

Headline

Used in bootstrapping to seperate sections

aclog().headline({ headline: 'AWS' })
// -> ****** AWS ********

functionStartLine

Used in to log the beginning of a function

aclog().functionStartLine({ headline: 'my function' })
// -> ______ My function ______

listing

Used in bootstrap

aclog().listing({ field: 'servername', value: 'localhost' })
// -> Servername:        localhost

TBC

Links

• Website
• Facebook

License

MIT License Copyright © 2009-present, AdmiralCloud AG, Mark Poepping