Create Database Connection Management

[CDiezRodriguez]

Description

Be able to connect to the postgresql

Acceptance Criteria

• Env Configuration: https://github.com/eclipse-tractusx/industry-core-hub/blob/main/charts/industry-core-hub/templates/deployment-backend.yaml#L65-L73
• Connect with the Metadata Registry

Additional Information

Example: https://github.com/vnurhaqiqi/fastapi-sqlmodel-postgresql/blob/master/app/db.py
SQLModel: https://sqlmodel.tiangolo.com/tutorial/connect/create-connected-rows/?h=connect#create-rows-for-teams-with-sqlmodel

[gomezbc]

I did some more research and found that we should follow the SQLModel recommendations for FastAPI by creating a dependency for the database connection. Check out the details here: SQLModel FastAPI Dependency. To connect to the postgresql we need to use a DSN connection string (e.g. postgres://user:pass@localhost:5432/foobar). I will update the helm chart to provide that string

We’ll use this dependency in every request as shown here: Using the Dependency.

To create the class with the connection, we could use pydantic settings management, which injects the configuration from ENV variables, https://docs.pydantic.dev/latest/concepts/pydantic_settings/#usage. Also, it has a type that will help us validate postgresql connection: https://docs.pydantic.dev/latest/api/networks/#pydantic.networks.PostgresDsn

[gomezbc]

The connection string will be introduced in #150 as DATABASE_CONNECTION_STRING