Running two NestJS applications in the same process - node.js

Question

I've been working with Express for a couple of years now and recently got introduced to NestJS. I decided to experiment and write an application on this, as it seemed to me, interesting framework.
I want my application to be able to handle the following routes:
General routes
/policy, /docs
API routes (with versioning)
/api/v1/users, /api/v1/chats
In Express, this is very easy to do, but as I understand it, in NestJS everything is different. As I understand from the documentation, in NestJS you cannot set the path prefix for the entire module. You can only set a global prefix for the entire application.
The documentation also talked about the RouterModule. But I didn’t like it, because it won’t be possible to enable versioning specifically for routes /api and the use of RouterModule itself is very inconvenient. As the application grows, using the RouterModule becomes a pain.
Then I tried to convert the application to a monorepository. It seems to be possible to achieve the desired functionality, but it seems inconvenient for me to run each part of the application separately. Perhaps it would be worth using concurrently, but in my opinion, this is also not the best option.
As a result, I came to the following solution.
The structure of my project at the moment looks like this:
project structure
The api directory will contain all modules related to the api (it will process /api/v1/... routes), and everything else will be in the core (it will process /docs, /policy routes, etc.).
In fact, everything is the same as when creating a monorepository, but I decided to run all this from a single main.ts
main.ts
And I have a question, what are the pitfalls of this solution? Will it affect performance? Are there any better options for solving my problem?

Answer 1

To enable versioning with NestJS :
const app = await NestFactory.create(AppModule);
app.enableVersioning({
type: VersioningType.URI,
});
await app.listen(3000);
Then, it's true that every routes will need version in URL: /v1/...
But you can use VERSION_NEUTRAL to mark default endpoint version :
Some controllers or routes may not care about the version and would
have the same functionality regardless of the version. To accommodate
this, the version can be set to VERSION_NEUTRAL symbol.
An incoming request will be mapped to a VERSION_NEUTRAL controller or
route regardless of the version sent in the request in addition to if
the request does not contain a version at all.
So, for example, here, route /v1/users for Users V1 only :
#Controller({
version: '1',
})
export class UsersControllerV1 {
#Get()
getUsers()...
}
and another route (controller) without any version :
#Controller({
version: VERSION_NEUTRAL,
})
export class PolicyController {
#Get()
getPolicy()...
}
Note that it's possible to provide more than one unique version :
version: ['1', VERSION_NEUTRAL]
More details on official docs.