Writing and Overriding Configuration¶

This guide explains how to write your own configuration file and use it to override the default behavior of pkg_infra.

How configuration override works¶

pkg_infra merges configuration from several locations. Later sources override earlier ones:

Ecosystem config
Packaged default config
User config
Working-directory config
Config file referenced by PKG_INFRA_CONFIG
Explicit custom config path passed by the caller

This means you usually do not need to rewrite the full default configuration. You can provide only the sections or values you want to change.

Minimal override example¶

The following file changes the active environment and the default logger:

app:
  environment: prod
  logger: verbose

Example with paths and integration settings¶

paths:
  log_dir: ./logs
  cache_dir: ./cache

integrations:
  corneto:
    settings:
      network_path: data/networks

Use a config file from the working directory¶

If you place a file named 04_workdir.yaml in the working directory, it will be picked up automatically.

Example:

logging:
  file_output_format: json

Use an explicit config file¶

You can also pass a custom config file directly when requesting the session:

from pathlib import Path

from pkg_infra import get_session

session = get_session(
    workspace=Path("."),
    config_path=Path("my_config.yaml"),
)

This is the highest-precedence source and is useful for experiments, environment-specific runs, or project-level overrides.

Use an environment variable¶

You can point pkg_infra to a config file with PKG_INFRA_CONFIG:

export PKG_INFRA_CONFIG=/path/to/config.yaml

Then create the session normally:

from pathlib import Path

from pkg_infra import get_session

session = get_session(workspace=Path("."))

Practical advice¶

Override only the keys you need
Keep package-specific settings under integrations
Keep logging changes inside the logging section
Use a custom file path for project-specific or temporary behavior
Validate changes by running the package and checking whether session creation succeeds