A script such as the one above should be added to the file /etc/logrotate.d/nginx for each vhost you are hosting which store their logs separate from Nginx’s main logs in order to cut back on the space being used to store these log files. THis Gist is basically a copy of Nginx’s own log rotation script and can be tailored to fit your needs. For …

nginx-logrotate.sh

/path/to/vhosts/domain.com/logs/*.log {
    daily
    missingok
    rotate 52
    compress
    delaycompress
    notifempty
    create 0640 www-data adm
    sharedscripts
    prerotate
        if [ -d /etc/logrotate.d/httpd-prerotate ]; then \
            run-parts /etc/logrotate.d/httpd-prerotate; \
        fi; \
    endscript
    postrotate
        [ ! -f /var/run/nginx.pid ] || kill -USR1 `cat /var/run/nginx.pid`
    endscript
}