Hello,
   During Shorewall/Shorewall6 installation the following files are installed:

/etc/logrotate.d/shorewall:

/var/log/shorewall-init.log {
  missingok
  notifempty
  create 0600 root root
}

/etc/logrotate.d/shorewall6:

/var/log/shorewall6-init.log {
  missingok
  notifempty
  create 0600 root root
}

/etc/logrotate.d/shorewall-init:

/var/log/shorewall-ifupdown.log {
  missingok
  notifempty
  create 0600 root root
}


    I think they look a bit strange. I suggest next variant:

/etc/logrotate.d/shorewall:

/var/log/shorewall.log {
    missingok
    notifempty
    create 0600 root root
    size 10M
    compress
    rotate 10
}

/etc/logrotate.d/shorewall6:

/var/log/shorewall6.log {
    missingok
    notifempty
    create 0600 root root
    size 10M
    compress
    rotate 10
}

/etc/logrotate.d/shorewall-init:

/var/log/shorewall-init.log {
  missingok
  notifempty
  create 0600 root root
}

/var/log/shorewall-ifupdown.log {
  missingok
  notifempty
  create 0600 root root
}