resources.md

# Resources service

## What it does
This service can provide lists of resources and formats.  
A resource is an entity representing some information, usually geographic, that can be accessed by a query (for example Web Map Service) or by downloading a file. One resource can be considered standard (e.g WMS protocol) or not standard (a custom service).  
Each resource is associated with one or many formats.

*Example:*  
the output of a Web Feature Service (WFS), standard service providing an interface for geographical features, is a resource. And it is associated with many formats as such Shapefile or JSON.  

## How it works

![resources-service](/assets/organizations-service.png)

The entrypoint of the service is a REST API provided by a [NestJS](https://github.com/nestjs/nest) application. This backend application interacts with a PostgresSQL database through an ORM called [TypeORM](https://github.com/typeorm/typeorm).


## API documentation

NestJS provides a swagger module that can be easily integrated. Using specific annotations alongside your endpoints declaration, this module will automatically generates a swagger documentation, reachable at `/api-doc`.

## Service health

NestJS provides a [health module](https://github.com/nestjs/terminus) based on Terminus, that gives you the opportunity to declare predifined or custom health indicators. It exposes the health status of the service at `/health`.  
This service will return a `200` http status code when all indicators are healthy. Otherwise it will return a `503` http status code. 

For this service we declared an health indicator that verifies that it can connect to the database.

## Stats

We are using a Node module called [swagger-stats](http://swaggerstats.io/).  
It traces API calls, monitors API performance and usage statistics. It exposes the metrics in different formats, such as Prometheus format, so you may use Prometheus and Graphana for API monitoring and alterting.  
Those metrics are available at `/swagger-stats/metrics`.

For more information about this module, visit the [official swagger-stat page](http://swaggerstats.io/docs.html).

## Docker
It is possible to run this service using Docker containers, using the `docker-compose.yml` and `Dockerfile` files.  
For more information, refer to the project [organizations-service][add a link]