aio-conf

AIO-Conf

AIO-Conf is a tiny configuration system that unifies values from multiple sources: command-line arguments, environment variables, configuration files and defaults. Specifications are declared up front so each option knows how to be parsed and coerced into the correct Python type.

Installation

This project uses Poetry. From the project directory install dependencies with:

poetry install

Defining a specification

You can declare options programmatically using OptionSpec and ConfigSpec:

from aio_conf.core import ConfigSpec, OptionSpec

spec = ConfigSpec([
    OptionSpec("port", int, default=8000, env="APP_PORT", cli="--port"),
    OptionSpec("debug", bool, default=False, env="APP_DEBUG", cli="--debug"),
])

The spec can also be stored in JSON and loaded with ConfigSpec.from_json_file() or via AIOConfig.load_from_spec().

Loading configuration

AIOConfig merges all sources with the following precedence:

1. CLI arguments
2. Environment variables
3. File values (json or yaml)
4. Defaults defined in the spec

from aio_conf import AIOConfig

cfg = AIOConfig(spec)
cfg.load(
    cli_args=["--port", "9000"],
    env={"APP_DEBUG": "true"},
    file_path="config.json",
)
print(cfg.as_dict())

The env parameter accepts a mapping of environment variables and defaults to os.environ when omitted.

Configuration can be written to an INI file:

cfg.save_ini("settings.ini")

Testing

Run the test suite with:

pytest -q