njs for nginx configuration

nginx_njs.md

NJS/nginScript

Configure nginx with HTTP JavaScript module using the --add-module option:

./configure --add-module=<path-to-njs>/nginx

Alternatively, you can build a dynamic version of the njs module

./configure --add-dynamic-module=<path-to-njs>/nginx

and add the following line to nginx.conf and reload nginx:

load_module modules/ngx_http_js_module.so;

JavaScript objects
------------------

$r
|- uri
|- method
|- httpVersion
|- remoteAddress
|- headers{}
|- args{}
|- response
  |- status
  |- headers{}
  |- contentType
  |- contentLength
  |- sendHeader()
  |- send(data)
  |- finish()

Example

Create nginx.conf:

worker_processes 1;
pid logs/nginx.pid;

events {
    worker_connections  256;
}

http {
    js_set $summary "
        var a, s, h;

        s = 'JS summary\n\n';

        s += 'Method: ' + $r.method + '\n';
        s += 'HTTP version: ' + $r.httpVersion + '\n';
        s += 'Host: ' + $r.headers.host + '\n';
        s += 'Remote Address: ' + $r.remoteAddress + '\n';
        s += 'URI: ' + $r.uri + '\n';

        s += 'Headers:\n';
        for (h in $r.headers) {
            s += '  header \"' + h + '\" is \"' + $r.headers[h] + '\"\n';
        }

        s += 'Args:\n';
        for (a in $r.args) {
            s += '  arg \"' + a + '\" is \"' + $r.args[a] + '\"\n';
        }

        s;
        ";

    server {
        listen 8000;

        location / {
            js_run "
                var res;
                res = $r.response;
                res.headers.foo = 1234;
                res.status = 302;
                res.contentType = 'text/plain; charset=utf-8';
                res.contentLength = 15;
                res.sendHeader();
                res.send('nginx');
                res.send('java');
                res.send('script');
                res.finish();
                ";
        }

        location /summary {
            return 200 $summary;
        }
    }
}

Run nginx & test the output:

$ curl 127.0.0.1:8000

nginxjavascript

$ curl -H "Foo: 1099" '127.0.0.1:8000/summary?a=1&fooo=bar&zyx=xyz'

JS summary

Method: GET
HTTP version: 1.1
Host: 127.0.0.1:8000
Remote Address: 127.0.0.1
URI: /summary
Headers:
  header "Host" is "127.0.0.1:8000"
  header "User-Agent" is "curl/7.43.0"
  header "Accept" is "*/*"
  header "Foo" is "1099"
Args:
  arg "a" is "1"
  arg "fooo" is "bar"
  arg "zyx" is "xyz"

--