I use forever to launch my nodeJs server and I choose the log file :
forever -l /home/api/log/api_output.log start server.js
I use logrotate to move logfile ever
I forgot copytruncate option in my config file, now it's working :
/etc/logrotate.d/api :
/home/api/log/api_output.log { #size 50k daily dateext missingok rotate 7 compress delaycompress notifempty #create 644 root copytruncate }