my ruby/rake daemon script logs to STDOUT. But thanks to systemd, logs are available to rsyslog.

systemd service:

[Unit]
Description=ruby rake daemon

[Service]
WorkingDirectory=/opt/rake/....
Type=simple
User=rake
Group=rake
ExecStart=/home/rake/.rbenv/shims/bundle exec rake ....
Restart=always
SyslogIdentifier=rake

ryslog conf /etc/rsyslog.d/rake.conf

:programname, isequal, "rake" /var/log/rake.log
& stop

It actually works but it buffers the data so log file is not updated right away when I tail it but it waits for a chunk of data (a few lines, it looks to me).

How do I disable buffering?