can't read "need_cookie": no such variable

It looks like you are only setting the need_cookie variable under certain conditions. So on any requests where those conditions are not met the variable $need_cookie is not set.

 

You need to ALWAYS set the need_cookie variable to some value (like at the top of the irule where you are setting the other variables) since you are calling for it unconditionally under the HTTP_RESPONSE event. Hope that makes sense.

 

-Joe