non tailable log when using Datetime templating

[nahuel]

With normal logs you can use tail -F to follow them, because when the log is rotated the original filename persists (and tail -F detects the file change). But when you use Datetime templates, it cannot follow it. It will be nice to apply the date template only at the archive time, so a "file.log" is always present and tailable, and when full is archived to "file.log.YYYY-MM-DD.gz"