This logic will fire only on the first access to a site during the session, then get out of the way for the remainder of the session. Something like this is what you're likely going to need to do:
when RULE_INIT {
set static::refresh_time 15
set static::notification_page {
System Notification
System Notification
This is an important announcement. You may need to take some sort of action, or no
action at all. It is important that you read this entirely. If some sort of action is
needed, then do it. Otherwise do nothing. That is all.
Wait $static::refresh_time seconds to continue, or click
}
}
when HTTP_REQUEST {
if { (not [HTTP::cookie exists NotificationDone]) } {
HTTP::respond 200 content [subst $static::notification_page] Mime-Type "text/html" Set-Cookie "NotificationDone=1; path=/; domain=.[HTTP::host]"
}
}
Nimbostratus
Altostratus