swn-logger

swaven-logger

Logging utility built over Winston

Provides a simple interface to log to stdout, file or redis.

Usage

var mainLogger = require('swn-logger').create('my-project', config),
    logger2 = require('swn-logger').create('subsystem')

mainLogger.info('Error')

API

create(system, [config])

Instanciates a logger for the given system.

Parameters:

system string, mandatory. The name of the logger.

config object. Logger configuration. Only needed for the first logger created for the application.
Properties:

• level: Possible values:debug, info, warn, error. Required level for events to be written. Events below this level are ignored. Defaults to debug.

• targets: Array of object. Defines log targets. Supported properties:

  name	type	mandatory*	transport	description
  type	string	✓	*	output destination: stdout, file, redis, datadog
  path	string	✓	file	path to file. folder must exist.
  host	string	✓	redis	redis host.
  port	string|number		redis	redis host port number. Can be ignored if host contains both, separated by colon :.
  key	string	✓	redis	key used to store events.
  service	string		datadog	service name
  hostname	string		datadog	logger host name
  secret	string	✓	datadog	AWS secret id for datadog API key.

• colors: object. Define alternate colors for stdout output. Each key is a log level, value is the associated color.

• quiet: boolean. Set to false to output system registration message. Default: true.

(*) mandatory if using the relevant output target.

debug(msg, [data])

warn(msg, [data])

info(msg, [data])

Logs an event with the appropriate level.

Parameters:

msg string. Event message

data object. Optional data, serialized and added to the event.

error(err, [data])

Logs an error.

Parameters:

err string, Error or VError. Error to log. If is an instance of Error or VError, the stack trace is logged. See VError for more details.

data object. Optional data, added to event if msg is a string.

ready

Returns a promise that resolves when all transports are initialized. Logging before that means losing logging for transports that are not ready.

Configuration example

var config = {
  level: 'debug',
  targets: [
    {
      type: 'stdout'
    },
    {
      type: 'file',
      path: 'trace.log'
      },
    {
      type: 'redis',
      host: '127.0.0.1:6379',
      key: 'test'
    },
    {
      type: 'datadog',
      hostname: 'test-instance', 
      service: 'foo',
      secret: 'aws-secret-id'
    }
  ]
}

var logger = require('swn-logger').create('test1', config)

await logger.ready

Notes

• Datadog apikey is retrieved asynchronously, and the transport is added async'ly too. Log messages before that will not be sent to datadog.
• the old redis dev dependency is necessary for winston-redis.