mxm-config 0.3.0

MXM configuration loader and context resolver

mxm-config

Purpose

mxm-config provides a unified way to install, load, layer, and resolve configuration across all Money Ex Machina (MXM) packages and applications.
It separates configuration from secrets and runtime metadata, enforces deterministic layering, and ensures every run has a transparent, reproducible view of its operating context.

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Design Principles

• Separation of concerns

  • Configuration ≠ secrets ≠ runtime.
  • Secrets are handled by mxm-secrets.
  • Runtime metadata will be handled by mxm-runtime (planned).

• Determinism

  • Configuration is layered in a fixed, documented order.
  • Reproducible runs: the same context always produces the same resolved config.

• Transparency

  • Configs are plain YAML files, no hidden state.
  • Merging order is explicit and testable.

• Extensibility

  • Layers are minimal and orthogonal.
  • New packages can register defaults without breaking existing ones.

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Configuration Layers

At runtime, configuration is resolved by merging up to six layers in order of precedence (lowest → highest):

1. default.yaml
   Baseline shipped with the package.
   Always present.

2. environment.yaml
   Deployment mode (dev, prod, …).
   Each environment is a block inside this file.

3. machine.yaml
   Host-specific overrides (paths, mounts, resources).

4. profile.yaml
   Role or user context (research, trading, …).

5. local.yaml
   Local scratchpad for ad-hoc tweaks.
   Ignored by version control.

6. Explicit overrides (dict)
   Passed directly in code, applied last.

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Installing Configs

Use the installer to copy package-shipped configs into the user’s config root (~/.config/mxm/ by default, override with $MXM_CONFIG_HOME).

from mxm_config.installer import install_all

install_all("mxm_config.examples.demo_config", target_name="demo")

This creates:

~/.config/mxm/demo/default.yaml
~/.config/mxm/demo/environment.yaml
~/.config/mxm/demo/machine.yaml
~/.config/mxm/demo/profile.yaml
~/.config/mxm/demo/local.yaml

Any templates/*.yaml files shipped with the package will also be installed under ~/.config/mxm/<package>/templates/.

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Loading Configs

from mxm_config.loader import load_config

cfg = load_config("demo", env="dev", profile="research")

print(cfg.parameters.refresh_interval)
print(cfg.paths.output)

• Context (mxm_env, mxm_profile, mxm_machine) is injected automatically.
• All ${...} interpolations are resolved before returning.
• The returned config is read-only by default.

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Example Package

The repo ships a minimal demo package: mxm_config/examples/demo_config

• default.yaml → valid baseline
• environment.yaml → defines dev and prod
• machine.yaml → overrides per host (bridge, wildling, monolith)
• profile.yaml → defines research, trading
• local.yaml → local overrides (optional, not versioned)

This serves as a test fixture for installers and loaders.

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Testing

Tests use pytest with monkeypatch to isolate config roots and hostnames.

Run with:

poetry run pytest

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Roadmap

• Config schema validation (via omegaconf.structured or pydantic)
• CLI tool (mxm-config install demo)
• Environment variable overrides → auto-mapped into overrides dict
• Integration with mxm-runtime for provenance tracking
• Config hashing for reproducibility and auditability

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License

MIT License. See LICENSE.