nginx request id

README.md

What you'll need

• nginx
• nginx-x-rid-header module (https://github.com/newobj/nginx-x-rid-header)

Why?

We want to track image downloads from client side and in javascript we cannot get the header values:(.

Logging

I used a terrible log format, you'd probably change that.

Inspiration

https://github.com/segmentio/request-id-middleware

nginx.conf

http {
  log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent" "$http_x_forwarded_for" '
                    'request-id:"$sent_http_x_request_id"';
  access_log  logs/access.log  main;

  server {
    server_name localhost;
    set $rid $request_id;
    if ($http_x_request_id != '') {
      set $rid $http_x_request_id;
    }
    if ($arg_requestId != '') {
      set $rid $arg_requestId;
    }
    add_header X-Request-Id $rid;
    root   html;
    index  index.html index.htm;
  }
}

result.md

Auto generating X-Request-Id

Command:

curl -I 192.168.0.100

Output:

HTTP/1.1 200 OK
Server: nginx/1.6.0
Date: Thu, 12 Jun 2014 07:34:40 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Wed, 11 Jun 2014 19:48:59 GMT
Connection: keep-alive
ETag: "5398b2ab-264"
X-Request-Id: 7ffce2be-30c9-4412-a8f8-8042f2657f4f
Accept-Ranges: bytes

Log:

192.168.0.120 - - [12/Jun/2014:09:34:40 +0200] "HEAD / HTTP/1.1" 200 0 "-" "curl/7.30.0" "-" request-id:"7ffce2be-30c9-4412-a8f8-8042f2657f4f"

Read from header

Command:

curl -I -H "X-Request-Id: request id from header" localhost

Output:

HTTP/1.1 200 OK
Server: nginx/1.6.0
Date: Thu, 12 Jun 2014 07:40:25 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Wed, 11 Jun 2014 19:48:59 GMT
Connection: keep-alive
ETag: "5398b2ab-264"
X-Request-Id: request id from header
Accept-Ranges: bytes

Log:

192.168.0.120 - - [12/Jun/2014:09:40:25 +0200] "HEAD / HTTP/1.1" 200 0 "-" "curl/7.30.0" "-" request-id:"request id from header"

Read from querystring

Command:

curl -I localhost?requestId=requestId-from-querystring

Output:

HTTP/1.1 200 OK
Server: nginx/1.6.0
Date: Thu, 12 Jun 2014 07:42:42 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Wed, 11 Jun 2014 19:48:59 GMT
Connection: keep-alive
ETag: "5398b2ab-264"
X-Request-Id: requestId-from-querystring
Accept-Ranges: bytes

Log:

192.168.0.120 - - [12/Jun/2014:09:42:42 +0200] "HEAD /?requestId=requestId-from-querystring HTTP/1.1" 200 0 "-" "curl/7.30.0" "-" request-id:"requestId-from-querystring"

Mixed (header and querystring)

Command:

curl -I -H "X-Request-Id: request-id from header" localhost?requestId=requestId-from-querystring

Output:

HTTP/1.1 200 OK
Server: nginx/1.6.0
Date: Thu, 12 Jun 2014 07:45:02 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Wed, 11 Jun 2014 19:48:59 GMT
Connection: keep-alive
ETag: "5398b2ab-264"
X-Request-Id: requestId-from-querystring
Accept-Ranges: bytes

usecase.js

var img = new Image();
var src = 'http://nginx-server.com/image.jpg';
var requestId = uuid.v4();
img.onerror = function() {
  // send an error to your server including requestId
  // and you can debug why the error happened
};
img.onload = function() {
  // now you can send analytics to your server
  // {
  //   "requestId": requestId,
  //   "src": src,
  //   "performance": window.performance.getEntries().slice(-1)
  //}

};
img.src = src + '?requestId=' + requestId;