logstar

logstar

Simple, opinionated, isomorphic logging.

It uses winston on the server and console.log on the client. It supports multiple arguments. If you have LOGGLY environment variables set, it will auto-configure the winston loggly transport.

Usage

import * as Logstar from 'logstar';

Logstar.debug('foo');
Logstar.info('bar');
Logstar.fatal('error', new Error('error'));

API

class Logger

import { Logger } from 'logstar';

constructor(options = {})

Configure loggly here. Optionally provide a globalMeta object to be attached to each log request.

{
  logLevel: 'info',
  loggly: {
    token: '',
    subdomain: '',
    tags: '',
  },
  globalMeta: {}
}

For JSON-logging, the following rules apply:

1. If there are exactly 2 arguments passed to the log function, and the second argument is an object, then that object is used as the meta parameter, and the first argument is used as the log message.
2. If there is exactly 1 argument passed to the log function, and that argument is an object, then that object is used as the meta parameter, with an empty log message.
3. In all other cases, the first argument is used as the log message, and the subsequent arguments are added as the context property on the meta object.

debug(...args)

debugf(format, ...args)

info(...args)

infof(format, ...args)

warn(...args)

warnf(format, ...args)

error(...args)

errorf(format, ...args)

fatal(...args)

fatalf(format, ...args)

transactionLogger

Get a logger that adds a transaction_id property to the meta. Useful for tracking related requests.

import { transactionLogger } from 'logstar';
const myLogger = transactionLogger('TRANSACTION-ID');

default

Logger pre-configured with loggly parameters from environment variables. (See below)

import Logstar from 'logstar';

Logstar.info('Hello', 12, { foo: 'bar' }, [1, 2, 3], new Error('Hello'));

// This will end up as:
{"level": "info", "message": "Hello", "context": [12, {"foo": "bar"}, [1, 2, 3], "Hello"]}

Configuration

ENV VARIABLES

LOG_LEVEL="debug" # Defaults to info
LOGGLY_SUBDOMAIN="mysubdomain"
LOGGLY_TAGS="api-server,production"
LOGGLY_TOKEN="secret-loggly-token-here"