Parse-logs NPM

parse-logs

Parse and validate logs to adhere to the message and meta standards from Lad and Cabin.

Install

npm install parse-logs

How does it work

This package exports a function that accepts two arguments req which is either ctx.request from Koa or req from Express, and userFields, which is an Array of user fields to pick using parse-request's userFields option (by default it is simply [ "ip_address" ]).

You use this function to parse an inbound HTTP request body in order to return and validate a log object.

In order for this to work properly, the body must already be a parsed Object (it cannot be a String).

For example, below is an example request Object that you can pass as req to parseLogs(req):

const parseLogs = require('.');

const req = {
  method: 'GET',
  query: {},
  headers: {
    'X-Request-Id': '123456',
    'User-Agent': 'Test User Agent'
  },
  cookies: {},
  body: {
    err: {
      message: 'Oops',
      stack: '...'
    },
    message: 'Oops',
    meta: {
      level: 'error',
      user: {
        id: '123456',
        email: 'test@example.com'
      }
    }
  },
  url: ''
};

console.log(parseLogs(req));

Outputs to console:

{
  err: Error: Oops
      at ... (::),
  message: 'Oops',
  meta: {
    level: 'error',
    user: { id: '123456', email: 'test@example.com' },
    id: '636e9a831bdc98012abd4519',
    timestamp: '2022-11-11T18:54:59.000Z',
    request: { method: 'GET', headers: [Object], id: '123456' },
    duration: 0.728459
  }
}

Note that there is a user object returned, which will be parsed from req.user automatically.

The user object will also have a ip_address property added, but only if one does not already exists and if an IP address was actually detected.

Additionally, err, meta.err, and meta.original_err properties from a request body payload will be parsed into Error objects with stack traces (normalized across Node and browser environments).

For an example implementation please refer to the Forward Email codebase.

Usage

Koa

const parseLogs = require('parse-logs');
const bodyParser = require('koa-bodyparser');

app.use(bodyParser());
app.use((ctx, next) => {
  const log = parseLogs(ctx.request);
  console.log(log);
  ctx.body = log;
});

Express

const parseLogs = require('parse-logs');
const bodyParser = require('body-parser');

app.use(bodyParser.json());
app.use(bodyParser.urlencoded());
app.use((req, res, next) => {
  const log = parseLogs(req);
  console.log(log);
  res.json(log);
});