ingot-settings

Sources and formats for the settings of Ingots beyond the standard library: an addon extending the settings unit of ingots.defaults. First YAML files, then loaders for cloud secret managers. Every integration is a unit behind an extra of its own, and nothing is wired in by default: an application installs the extras it uses and joins their settings with its own.

from ingot_settings.yaml import YamlSettings  # pip install "ingot-settings[yaml]"
from ingots.defaults import Project
from ingots.puer import Slot


class AppSettings(HttpSettings, YamlSettings):
    pass


class AppProject(Project):
    env_configs_prefix = "APP"
    settings = Slot(AppSettings)

Importing a unit without its extra fails at once, naming the extra.

YAML files

ingot_settings.yaml, the yaml extra: YamlSettings read --configs-file in YAML too (.yaml, .yml), next to INI and JSON: a mapping of config names to values.

HTTP_HOST: example.com
HTTP_PORT: 9090
IS_STRICT_CONFIGS: true

The file is read with the base loader of PyYAML, which resolves no types: every scalar is a string, converted by its config as an environment variable is. NO stays "NO" for a string config and is a false for a bool one; the booleans, octals and dates of YAML 1.1 do not apply. A sequence or a mapping reaches its config as a list or a dict, which the config rejects unless it converts them: such an override is wrong. A tag (!!int, !!python/object) and a key given twice are errors. An alias may repeat a scalar, HOST: &host db.internal then OTHER_HOST: *host, but not a sequence or a mapping, which would nest into data exponentially larger than the file (billion laughs); the aliases together may repeat at most as many characters as the file holds.

Joining units

Units that extend different slots join as they are. Two that extend the same one, such as two file loaders with formats of their own, take a class extending both: ingots (and mypy) reject the settings until they declare it.

class AppFileLoader(YamlFileLoader, TomlFileLoader):
    pass


class AppSettings(YamlSettings, TomlSettings):
    file_loader = Slot(AppFileLoader)

Status: pre-alpha: YAML files.

Development

Requires uv and make; uv fetches the interpreters it needs.

make                 # the target list
make check           # everything CI runs: lint, test, coverage, wheel-test, cl-check
make format          # black
make all             # build the sdist and the wheel into dist/

• Every change users should know about adds a news fragment to changelog.d/ (see its README).
• A release is a pull request setting the version (uv version X.Y.Z) and collating the changelog (make cl-build VERSION=X.Y.Z), then the tag vX.Y.Z on main: the release workflow publishes the tested build to TestPyPI, then to PyPI. Run by hand, it rehearses on TestPyPI only.

License

Apache 2.0.