Logs - rejetto/hfs GitHub Wiki
We keep logs in Apache's Common Log format. To it we add an extra multiple-purpose field, a dictionary/object serialized as JSON, and then surrounded with double-quotes to comply with log's format (you need to JSON.parse twice to decode it).
Rotation
You can decide rotation a period. At the end of the period, the current log file is renamed, appending a timestamp to the name, and a new (empty) file is started. HFS is currently never deleting such files, so it's up to you. Keep an eye on it before your disk gets full.