Create and control log level by env (Example: `LIMIT_LOG=abc-module.*= verbose; main= info; x-module.api= warn`)

log-manager.js

import { loggers, format, transports } from 'winston';
import { inspect } from 'util';

const myFormat = format.printf((info) => {
  const { level, message, label, timestamp } = info;
  const extra = info[Symbol.for('splat')];
  let text = `${timestamp} [${label}] ${level}: ${message}`;

  if (extra) {
    for (let index = 0; index < extra.length; index++) {
      const e = extra[index];

      if (typeof e === 'object') {
        text += ` ${inspect(e, { showHidden: false, colors: true, depth: 2 })}`;
      } else {
        text += ` ${e}`;
      }
    }
  }

  return text;
});

let config;
let defaultLevel = 'info';
let groupLog;

if (process.env.LIMIT_LOG) {
  defaultLevel = 'disable';
  config = {};
  groupLog = [];

  const parsed = process.env.LIMIT_LOG.split(';');

  for (let index = 0; index < parsed.length; index++) {
    let label;
    let level = 'info';
    const cf = parsed[index];

    if (cf.indexOf('=') > -1) {
      [label, level] = cf.split('=');
      label = label.trim();
      level = level.trim();
    } else {
      label = cf.trim();
    }

    if (label === '*') {
      defaultLevel = level;
    } else if (label.endsWith('.*')) {
      groupLog.push({ group: label.substring(0, label.length - 2), level });
    } else {
      config[label] = level;
    }
  }
}

/**
 * @param {string} label
 */
export function createLogger(label) {
  let minLevel;
  let silent = false;

  if (config?.[label]) {
    minLevel = config[label];
  } else if (groupLog) {
    for (let index = 0; index < groupLog.length; index++) {
      const element = groupLog[index];
      if (label.startsWith(element.group)) {
        minLevel = element.level;
      }
    }
  }

  if (!minLevel) {
    if (defaultLevel === 'disable') {
      silent = true;
    } else {
      minLevel = defaultLevel;
    }
  }

  let formatLog;
  if (process.env.NODE_ENV === 'development') {
    formatLog = format.combine(
      format.label({ label }),
      format.timestamp({ format: 'HH:mm:ss' }),
      format.colorize(),
      myFormat
    );
  } else {
    formatLog = format.combine(
      format.label({ label }),
      format.timestamp(),
      format.json({ maximumDepth: 2 })
    );
  }

  return loggers.add(label, {
    silent,
    level: minLevel,
    format: formatLog,
    transports: [new transports.Console()]
  });
}