JSPM

  • ESM via JSPM
  • ES Module Entrypoint
  • Export Map
  • Keywords
  • License
  • Repository URL
  • TypeScript Types
  • README
  • Created
  • Published
  • Downloads 22958
  • Score
    100M100P100Q149127F
  • License ISC

Simple json logger middleware with namespaces

Package Exports

  • @emartech/json-logger

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (@emartech/json-logger) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

json-logger-js

Simple JSON logger middleware that combines the namespaces of debug and the machine readable JSON format of bunyan.

It has the same logging levels as bunyan.

Example logging

process.env.DEBUG = 'redis';
const mongoLogger = require('@emartech/json-logger')('mongo');
const redisLogger = require('@emartech/json-logger')('redis');

// simple info logging with enabled namespace
redisLogger.info('connected', { domain: 'yahoo' });

// not enabled
mongoLogger.info('connected', { domain: 'google' });

// error objects
redisLogger.fromError('query', new Error('Unauthorized'), { problem: 'missmatch' });

will output

{"name":"redis","action":"connected","level":30,"time":"2016-08-15T08:50:23.566Z","domain":"yahoo"}
{"name":"redis","action":"query","level":50,"time":"2016-08-15T08:50:23.569Z","error_name":"Error","error_stack":"Error: Unauthorized\n    at Object.<anonymous> (/home/blacksonic/workspace/bunyan-debug/example.js:15:32)\n    at Module._compile (module.js:541:32)\n    at Object.Module._extensions..js (module.js:550:10)\n    at Module.load (module.js:458:32)\n    at tryModuleLoad (module.js:417:12)\n    at Function.Module._load (module.js:409:3)\n    at Module.runMain (module.js:575:10)\n    at run (bootstrap_node.js:352:7)\n    at startup (bootstrap_node.js:144:9)\n    at bootstrap_node.js:467:3","error_message":"Unauthorized","problem":"missmatch"}

Examples can be found in examples/index.js.

Logging request identifier automatically

The library provides middlewares for both Koa and Express applications. These middlewares add the request identifiers coming from the header X-Request-Id to every log (in the log: request_id).

const Koa = require('koa');
const logFactory = require('@emartech/json-logger');

app.use(logFactory.getMiddleware());

The method getMiddleware creates a Koa middleware (alias for getKoaMiddleware). The getExpressMiddleware method does the same, but returns an Express middleware.

Development

While developing JSON is not the most readable format. To solve this a little command line formatter is also included which is very familiar to debug's output format.

redis INFO +0ms action="connected" domain="yahoo"
redis ERROR +2ms action="query" error_message="Unauthorized" error_name="Error" error_stack="Error: Unauthorized\n    at Object.<anonymous> (/home/blacksonic/workspace/bunyan-debug/example.js:15:32)\n    at Module._compile (module.js:541:32)\n    at Object.Module._extensions..js (module.js:550:10)\n    at Module.load (module.js:458:32)\n    at tryModuleLoad (module.js:417:12)\n    at Function.Module._load (module.js:409:3)\n    at Module.runMain (module.js:575:10)\n    at run (bootstrap_node.js:352:7)\n    at startup (bootstrap_node.js:144:9)\n    at bootstrap_node.js:467:3" problem="missmatch"