wazuh-kibana-app/server/logger.js

/*
 * Wazuh app - Module for logging functions
 * Copyright (C) 2018 Wazuh, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Find more information about this on the LICENSE file.
 */
import winston from 'winston';
import fs      from 'fs';
import path    from 'path';

let allowed = false;
let wazuhlogger = undefined;

/**
 * Here we create the logger
 */
const initLogger = () => {
    wazuhlogger = winston.createLogger({
        level     : 'info',
        format    : winston.format.json(),
        transports: [
            new winston.transports.File({
                filename: path.join(__dirname, '../../../optimize/wazuh-logs/wazuhapp.log')
            })
        ]
    });
    
    /**
     * Prevents from exit on error related to the logger.
     */
    wazuhlogger.exitOnError = false;  
};

/** 
 * Checks if wazuh-logs exists. If it doesn't exist, it will be created.
 */
const initDirectory = async () => {
    try{
        if(!path.join(__dirname).includes('/usr/share/kibana') &&
            path.join(__dirname).includes('plugins') &&
            path.join(__dirname).includes('kibana')){

            throw new Error('Kibana is out of /usr/share/kibana path and the Wazuh App is inside plugins directory')

        }
        if (!fs.existsSync(path.join(__dirname, '../../../optimize/wazuh-logs'))) {
            fs.mkdirSync(path.join(__dirname, '../../../optimize/wazuh-logs'));
        }
        if(typeof wazuhlogger === 'undefined') initLogger();
        allowed = true;
        return;
    } catch (error) {
        allowed = false;
        return Promise.reject(error);
    }
}


/**
 * Returns given file size in MB, if the file doesn't exist returns 0
 * @param {*} filename Path to the file
 */
const getFilesizeInMegaBytes = filename => {
    if(allowed){
        if (fs.existsSync(filename)) {
            const stats               = fs.statSync(filename)
            const fileSizeInMegaBytes = stats.size

            return fileSizeInMegaBytes / 1000000.0;
        }
    }
    return 0;
}

/**
 * Checks if the wazuhapp.log file size is greater than 100MB, if so it rotates the file.
 */
const checkFiles = () => {
    if(allowed){
        if (getFilesizeInMegaBytes(path.join(__dirname, '../../../optimize/wazuh-logs/wazuhapp.log')) >= 100) {
            fs.renameSync(
                path.join(__dirname, '../../../optimize/wazuh-logs/wazuhapp.log'),
                path.join(__dirname, `../../../optimize/wazuh-logs/wazuhapp.${new Date().getTime()}.log`)
            );
            fs.writeFileSync(path.join(__dirname, '../../../optimize/wazuh-logs/wazuhapp.log'),JSON.stringify({
                date    : new Date(),
                level   : 'info',
                location: 'logger',
                message : 'Rotated log file'
            }) + '\n');
        }
    }
};


/**
 * Main function to add a new log
 * @param {*} location File where the log is being thrown
 * @param {*} message Message to show
 * @param {*} level Optional, default is 'error'
 */
export default (location, message, level) => {
    initDirectory()
    .then(() => {
        if(allowed){
            checkFiles();
            wazuhlogger.log({
                date    : new Date(),
                level   : level || 'error',
                location: location || 'unknown',
                message : message || 'An error occurred'
            });
        }
    })
    .catch(error => console.error(`Cannot create the logs directory due to:\n${error.message || error}`));
};