OpenMetrics support for textfile collector

Currently prometheus_client.exposition.write_to_textfile doesn't support the OpenMetrics text format, which I'm addressing with this (private) hack:

from prometheus_client.openmetrics.exposition import (
    generate_latest as generate_latest_openmetrics,
)
from prometheus_client.registry import CollectorRegistry

def write_openmetrics_to_textfile(path: str, registry: CollectorRegistry) -> None:
    """
    Fork of `prometheus_client.exposition.write_to_textfile`, as the project
    didn't provide an OpenMetrics variant of this helper function.
    """
    with open(path, "wb") as fp:
        fp.write(generate_latest_openmetrics(registry))

Would your project be interested in a non-hacky (as is the case above) OpenMetrics support for textfile collector?

Commencez par prometheus_client.exposition.write_to_textfile et comparez son comportement avec celui de prometheus_client.openmetrics.exposition.generate_latest. Déterminez comment le helper doit exposer la sortie OpenMetrics tout en préservant le comportement existant du collector de fichiers texte. Le travail est terminé lorsque le helper pris en charge écrit un texte OpenMetrics valide pour le registry fourni et est couvert par les tests pertinents du projet.