Serialize selected config groups at runtime

[addisonklinke]

Similar to how Hydra automatically tracks overrides.yaml - is it possible to determine from an application's code what config groups were selected at runtime? You could attempt to parse the overrides, i.e. ones containing / are obviously config groups, but if there's no nesting you can't tell the difference between a group and top-level field

[Jasha10]

Yes, see hydra.runtime.choices.
You can access it using the hydra resolver (${hydra:runtime.choices}) or in your python code as below:

from omegaconf import DictConfig
import hydra
from hydra.core.hydra_config import HydraConfig

@hydra.main(version_base=None, config_path="conf", config_name="config")
def my_app(cfg: DictConfig) -> None:
    print(HydraConfig.get().runtime.choices)

if __name__ == "__main__":
    my_app()