This repository simply builds a container for ottdstats, a statistic collection backend for OpenTTD.
Mount your config.json at /app/config.json.
Alternatively, you can mount it wherever you want, and launch with something like the following:
docker run -it --rm -v /home/duck/my_ottdstats_config.json:/config/config.json redditopenttd/ottdstats --config /config/config.json