simpl-loggar/lib/logger.js

Simple node.js logger

import { ecsFormat } from '@elastic/ecs-winston-format';
import * as winston from 'winston';
import DailyRotateFile from 'winston-daily-rotate-file';
import LokiTransport from 'winston-loki';
export default class Logger {
    static _config = {};
    static get config() {
        return Logger._config;
    }
    static set config(val) {
        Logger._config = val;
    }
    static getLogger(prefix, config) {
        if (!Logger.instance || Logger?.config.addons?.loki !== config?.addons?.loki) {
            if (config)
                Logger.config = config;
            Logger.createInstance(prefix, config);
        }
        return Logger.instance;
    }
    static #instance_accessor_storage = undefined;
    static get instance() { return Logger.#instance_accessor_storage; }
    static set instance(value) { Logger.#instance_accessor_storage = value; }
    static createInstance(prefix, config) {
        if (Logger.instance) {
            Logger.instance.clear();
            Logger.instance.close();
            Logger.instance = undefined;
        }
        let path = process.env[process.platform === 'win32' ? 'USERPROFILE' : 'HOME'];
        const cache = process.platform === 'win32' ? 'AppData/Roaming/' : '.cache';
        const name = process.env.APP_NAME ?? process.env.npm_package_name ?? 'unnamed';
        path += `/${cache}`;
        if (prefix)
            path += `/${prefix}`;
        path += `/${name}/`;
        if (!name) {
            console.warn('Logger', "Missing 'name' field in package.json. Defaulting log files to 'unnamed'");
        }
        const levels = process.env.NODE_ENV === 'production'
            ? ['error', 'warn', 'info', 'verbose']
            : ['error', 'warn', 'info', 'debug', 'verbose'];
        const transports = [
            ...levels.map((l) => {
                return new DailyRotateFile({
                    level: l,
                    filename: `${path}logs/errors-%DATE%.log`,
                    json: true,
                    format: winston.format.combine(winston.format.timestamp(), winston.format.align(), winston.format.printf((info) => `[${info.timestamp}] ${info.level}: ${info.message}`)),
                    datePattern: 'yyyy-MM-DD',
                    maxFiles: 30,
                    handleExceptions: true,
                    handleRejections: true,
                });
            }),
        ];
        if (config?.addons?.loki) {
            transports.push(new LokiTransport({
                host: config.addons.loki,
                labels: { app: name },
                json: true,
                format: winston.format.json(),
                replaceTimestamp: true,
                onConnectionError: (err) => {
                    console.info('Simple logger. Loki connector threw an error');
                    console.info(err);
                },
            }));
        }
        Logger.instance = winston.createLogger(config?.winston ?? {
            level: process.env.NODE_ENV === 'production' ? 'verbose' : 'debug',
            format: ecsFormat(),
            transports,
        });
    }
}