I found a section on the nginx docs that you can use
ECMAScript 5.1 (strict mode) with some ECMAScript 6 and later extensions
to extend nginx. As use case
Complex access control and security checks in njs before a request reaches an upstream server
https://nginx.org/en/docs/njs/
No i wonder if im able to connect to a database and do something similar as in node.js. Or even "run" node inside of the nginx process. But I think I have bad cards because there are currently only two modules, which provide no functionality like network sockets, but, there is a section "Using node modules with njs": https://nginx.org/en/docs/njs/node_modules.html.
Works this only with externeal libs or also with "node internals" like net, dgram, etc.?
njs is a subset of Javascript and currently lacks any means of interfacing with external processes directly, however can make sub-requests to local routes which can in turn proxy other services. I stumbled upon your question while researching a similar requirement and published a simple example here:
The nearest thing to a solution effectively means creating a thin wrapper around your database connectivity and deploying it as an independent web-service, then setting up an internal route to reverse-proxy the connection:
location /internal-service {
internal;
proxy_pass http://<hostname>:<port>;
}
Your njs script can then defer to the route by calling:
response.subrequest(
'/internal-service',
{
method: 'GET',
},
serviceResponse => {
// some logic...
response.return(200)
}
)
There may be other workarounds but this approach seems to be the most robust at the moment. It does unfortunately make it difficult to develop self-contained modules - which I suspect is one of the reasons why there aren't really any reusable packages available.