bunyan-logger-factory

Why I create this libray

From time to time, I found I have to create Bunyan instance with different streams(stdout/file/syslog) for different environments.

How to use

const loggerFactory = require('bunyan-logger-factory');

const myLogger = loggerFactory.init({
  logName: 'my-logger-name',
  logStream: process.env.LOGSTREAM,
  logHost: process.env.LOGHOST,
  logPort: process.env.LOGPORT,
  logProto: process.env.LOGPROTO
});

Advanced usage

You can also set the transformation to the logger.

constant

const loggerFactory = require('bunyan-logger-factory');

const myLogger = loggerFactory.init({
  logName: 'my-logger-name',
  logStream: process.env.LOGSTREAM,
  logHost: process.env.LOGHOST,
  logPort: process.env.LOGPORT,
  logProto: process.env.LOGPROTO,
  transform: [
    {
      constant: {
        ipsum: 'xxx',
      },
    },
  ],
});

This will add ipsum: xxx to each log created.

clone

const loggerFactory = require('bunyan-logger-factory');

const myLogger = loggerFactory.init({
  logName: 'my-logger-name',
  logStream: process.env.LOGSTREAM,
  logHost: process.env.LOGHOST,
  logPort: process.env.LOGPORT,
  logProto: process.env.LOGPROTO,
  transform: [
    {
      clone: {
        msg: 'message',
        time: 'timestamp',
      },
    },
  ],
});

This will generate two extra fields message and timestamp which have exact same value as msg and `time**.

map

const loggerFactory = require('bunyan-logger-factory');
const fn = (v) => {return v + v;};

const myLogger = loggerFactory.init({
  logName: 'my-logger-name',
  logStream: process.env.LOGSTREAM,
  logHost: process.env.LOGHOST,
  logPort: process.env.LOGPORT,
  logProto: process.env.LOGPROTO,
  transform: [
    {
      map: {
        foo: fn,
      },
    },
  ],
});

This will populate the value of foo by calling the fn function.

avoidChildTransform

By default, the logger.child will inherit the transformation you set on the parent if there is a tranform in the init function, you can set avoidChildTransform to true to prevent that behavior.

const logger = loggerFactory.init({
  logName: 'test-logger',
  logStream: 'FILE',
  logPath: filePath,
  avoidChildTransform: true, // the transform only applies on the current logger instance.
  transform: [
    {
      constant: {
        ipsum: 'xxx',
      },
    },
  ],
});

License

MIT