Express-mw-correlation-id NPM

express-mw-correlation-id

Correlates HTTP requests between a client and server

api

const setCorrelationId = require('express-mw-correlation-id')

**setCorrelationId(string, defaults to X-Request-ID, formatter=identity)

by default will use the X-Request-ID header but to use a custom header instead just pass the name in the first parameter
formatter is a function that will add custom formats to the generated ID, being, by default, the generated ID.
the middleware will reuse the request id if already present in the request headers

req.id now is expose to be used internally by the api/service is using the express-mw-correlation-id middleware

examples

const express = require('express')
const setCorrelationId = require('express-mw-correlation-id')

const app = express()

app.use(setCorrelationId())

// `req.id` hold the correlation/request id
app.get('/', (req, res) => { res.send(req.id) })

app.listen(3000)

Custom ID

app.use(setCorrelationId('X-Custom-ID'))

Custom ID and custom format

app.use(setCorrelationId('X-Custom-ID', (id) => id))

Custom format

app.use(setCorrelationId((id) => id))

client

curl -v http://localhost:3000
* Rebuilt URL to: http://localhost:3000/
*   Trying ::1...
* Connected to localhost (::1) port 3000 (#0)
> GET / HTTP/1.1
> Host: localhost:3000
> User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)
> Accept: */*
> Referer:
>
< HTTP/1.1 200 OK
< X-Powered-By: Express
< X-Request-ID: 825efe65-a27d-4dca-936b-e74249095fb7
< Content-Type: text/html; charset=utf-8
< Content-Length: 11
< ETag: W/"b-sQqNsWTgdUEFt6mb5y4/5Q"
< Date: Thu, 08 Dec 2016 10:22:44 GMT
< Connection: keep-alive
<
* Connection #0 to host localhost left intact
825efe65-a27d-4dca-936b-e74249095fb7

X-Request-ID should come with the headers