Create config loading from .yaml files

[pavleprica]

We would like to achieve to have the possibility to load predefined .yaml files for loading app configuration.

To give an example:
Let's assume we have three environments.

• local
• dev
• prod

For the local environment, we could be free to specify any values, not being worried about security. For example if you are running a local postgress version, you don't mind if you commit the file with password: 12345.

Though for the dev and prod environment, we would want to abstract that to being read from a environment variable. So it would look more like password: ${DB_PASSWORD}.

An example of file content

config-local.yaml

database:
  username: user
  password: my-secret-pw

config-dev.yaml

database:
  username: ${DATABASE_USERNAME}
  password: ${DATABASE_PASSWORD}

In the config-dev.yaml example, it will load the environment config, and load from the system environment the values for these keys.

This of course has to be available and accessible through code for fetching values.