minicfg

📑 minicfg is a lightweight, minimalistic and easy-to-use configuration package for your Python services.

Features

• Lightweight: minicfg is a small package with no dependencies.
• Easy to use: minicfg provides a simple API to define and populate configurations.
• Documentation: generate documentation for your configuration.
• Type casting: minicfg supports type casting for the fields. You can also define your own casters.
• File field attachment: minicfg supports attaching a virtual file field to a field.
• Prefixing: minicfg supports prefixing the fields with a custom name prefix.
• Nested configurations: minicfg supports nested configurations.
• Custom providers: minicfg supports custom providers to populate the configuration from different sources.

Installation

Just install minicfg using your favorite package manager, for example:

pip install minicfg

Usage

from minicfg import Minicfg, Field, minicfg_name
from minicfg.caster import IntCaster


@minicfg_name("SERVICE")
class MyConfig(Minicfg):
    @minicfg_name("DATABASE")
    class Database(Minicfg):
        HOST: str = Field(attach_file_field=True, description="database host")
        PORT: int = Field(default=5432, caster=IntCaster(), description="database port")

    @minicfg_name("EXTERNAL_API")
    class ExternalAPI(Minicfg):
        KEY: str = Field(description="external API key")
        USER_ID: int = Field(caster=IntCaster(), description="external API user ID")


if __name__ == '__main__':
    config = MyConfig()  # create an instance of the configuration
    config.populate()  # populate the configuration from the environment variables

    print(f"connect to database at {config.Database.HOST}:{config.Database.PORT}")
    print(f"external API key: {config.ExternalAPI.KEY}")
    print(f"external API user: {config.ExternalAPI.USER_ID}")

Try running the script with the following environment variables:

• SERVICE_DATABASE_HOST=example.com
• SERVICE_DATABASE_PORT=5432
• SERVICE_EXTERNAL_API_KEY=token
• SERVICE_EXTERNAL_API_USER_ID=123

And you should see the following output:

connect to database at example.com:5432
external API key: token
external API user: 123

More examples are available here.

Documentation generation

You can use minicfg script to generate documentation for your configuration.

For example, minicifg --format=markdown example.MyConfig will generate documentation for the MyConfig class above, and it would look like this:

SERVICE

Name	Type	Default	Description

SERVICE_DATABASE

Name	Type	Default	Description
SERVICE_DATABASE_HOST	str	N/A	database host
SERVICE_DATABASE_HOST_FILE	str	N/A	database host file
SERVICE_DATABASE_PORT	int	5432	database port

SERVICE_EXTERNAL_API

Name	Type	Default	Description
SERVICE_EXTERNAL_API_KEY	str	N/A	external API key
SERVICE_EXTERNAL_API_USER_ID	int	N/A	external API user ID