aono-file-handler/LogstashFormatter.js

Aono handler that write to a log file with support for custom formatters and log rotation.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.LogstashFormatter = void 0;
/**
 * @author Maciej Chałapuk (maciej@chalapuk.pl)
 */
class LogstashFormatter {
    constructor(prefix = 'data_', consts = {}) {
        this.prefix = prefix;
        this.consts = consts;
    }
    format(entry) {
        const date = new Date();
        date.setTime(entry.timestamp);
        const formattedDate = date.toISOString();
        const message = '{ ' +
            `"timestamp": ${safeJsonStringify(formattedDate)}, ` +
            `"logger": ${safeJsonStringify(entry.logger)}, ` +
            `"level": ${safeJsonStringify(entry.level)}, ` +
            `"message": ${safeJsonStringify(entry.message)}` +
            Object.keys(this.consts)
                .map(key => `, "${key}": ${safeJsonStringify(this.consts[key])}`)
                .join('') +
            Object.keys(entry.data)
                .map(key => `, "${this.prefix}${key}": ${safeJsonStringify(entry.data[key])}`)
                .join('') +
            ' }\n';
        const utfEncoded = encodeUtf(message);
        return utfEncoded;
    }
}
exports.LogstashFormatter = LogstashFormatter;
exports.default = LogstashFormatter;
function safeJsonStringify(obj) {
    try {
        if (obj instanceof Error && obj.stack) {
            // Errors are stringified to arrays containing stack trace
            // which will render nicely in Kibana.
            return JSON.stringify(obj.stack.split('\n'));
        }
        else {
            return JSON.stringify(obj);
        }
    }
    catch (e) {
        return `["### Error while stringifying object of type ${typeof obj} ###","${e.message}"]`;
    }
}
function encodeUtf(message) {
    return message.replace(/[\u00A0-\u9999<>\&]/gim, i => {
        const hex = i.charCodeAt(0).toString(16);
        return `\\u${(hex.length === 2 ? '00' : '')}${hex}`;
    });
}
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