file-to-sumo/src/service/loggerservice.js

stream logs from a file to sumologic hosted collector

const fs = require('fs'),
    path = require('path'),
    SumoLogger = require('sumo-logger'),
    util = require('util'),
    uuidv4 = require('uuid/v4');

const LOG_FAILURE_PATH = './logfailures.log';


class LoggerService {
    constructor(opts) {
        if (!LoggerService.loggerInstance) {
            this.opts = this.initOptions(opts);
            this.sumoLogger = new SumoLogger(this.opts);
            LoggerService.loggerInstance = this;
        }
        return LoggerService.loggerInstance;
    }

    initOptions(opts) {
        let sumoLoggerOptions = {};
        sumoLoggerOptions['endpoint'] = opts.sumoEndpoint;
        sumoLoggerOptions['clientUrl'] = opts.sumoClientUrl;
        sumoLoggerOptions['interval'] = opts.sumoInterval;
        sumoLoggerOptions['hostName'] = opts.sumoHostName;
        sumoLoggerOptions['sourceName'] = opts.sumoSourceName;
        sumoLoggerOptions['sourceCategory'] = opts.sumoSourceCategory;
        sumoLoggerOptions['sessionKey'] = uuidv4();
        sumoLoggerOptions['onSuccess'] = () => {};
        sumoLoggerOptions['onError'] = (err) => {
            const absolutePath = path.resolve(LOG_FAILURE_PATH);
            fs.writeFile(absolutePath, this.prepareErrorLog(err, opts), 'utf8', (err) => {
                if (err) {
                    console.error('Error in updating log failures. Exiting...');
                    return;
                };
            });
        };
        return sumoLoggerOptions;
    }

    log(incomingMessage) {
        //sanitize new lines 
        let parsedMessage;
        try {
            parsedMessage = JSON.parse(incomingMessage.replace(/\n$/g, ''));
        } catch (err) {
            parsedMessage = incomingMessage;
        }
        
        this.sumoLogger.log(parsedMessage);            
    };

    flushLogs() {
        this.sumoLogger.flushLogs();
    }

    prepareErrorLog(err, opts) {
        let log = {};
        log['timestamp'] = new Date().toISOString();
        log['error'] = err;
        log['endpoint'] = opts.sumoEndpoint;
        return util.inspect(log) + '\r\n';
    }
}

module.exports = LoggerService;