@hoangnam.io/qa-tools/logging/log-format.js

Logging, Error handling, Notifying for Express codebase

const { trace, context } = require("@opentelemetry/api");
const moment = require("moment-timezone");
const { LogLevel } = require("./constance");

function genLogFormatFunc(config) {
  const { app, appName, TZ, extractCallerFunc, sensitiveRoutes } = config;

  // record response body
  const originalSend = app.response.send;
  app.response.send = function sendOverride(body) {
    this.responseBody = Buffer.isBuffer(body) ? body.toString() : body;
    return originalSend.call(this, body);
  };

  return function logFormatFunction(tokens, req, res) {
    const activeSpan = trace.getSpan(context.active());
    const { traceId, spanId, traceFlags } = activeSpan?.spanContext() || {};
    const logEntry = {
      severity: LogLevel.INFO,
      appName,
      logType: "RequestLog",
      zTimestamp: moment.tz(TZ).format(),
      timestamp: Date.now(),
      caller: extractCallerFunc(req),
      userAgent: req.headers["user-agent"],
      ip: req.ip,
      method: tokens.method(req, res),
      url: tokens.url(req, res),
      requestContentLength: req.headers["content-length"],
      responseContentLength: Number(tokens.res(req, res, "content-length")),
      contentLengthUnit: "bytes",
      responseTime: Number(tokens["response-time"](req, res)),
      responseTimeUnit: "ms",
      status: res.statusCode,
      query: req.query,
      params: req.params,
      extended: req.extendedLog,
      traceId,
      spanId,
      traceFlags,
    };
    // in case of error requests
    if (res.statusCode >= 400) {
      logEntry.severity = LogLevel.ERROR;
      try {
        logEntry.responseBody = JSON.parse(res.responseBody);
      } catch {
        logEntry.responseBody = res.responseBody;
      }
      logEntry.body = sensitiveRoutes.some((route) => req.url.includes(route)) ? "*" : req.body;
    }
    return JSON.stringify(logEntry);
  };
}

module.exports = { genLogFormatFunc };