Adding custom field to Apollo router logs

Hi,
We try to use the Apollo router (Rust version) as our federated router. We deploy it as a docker container. Based on configuration (and inspection of docker logs) - the service writes the logs in JSON format.
Our logging collection system requires a JSON output + a specific field to appear in the output - facility, which should include the service name.

What is the recommended way to add this custom field to all output logs?