Forum Discussion
IT
Nimbostratus
NimbostratusPersistence problem after modifying Set-Cookie
Hi,
We use cookie persistence on a VS in front of some tomcat servers.
Our goal is to add the domain at the end of every cookie in an HTTP response (BIGIP cookie, JSESSIONID cookie...)
So we have developped our first iRule, here is the code :
when HTTP_REQUEST {
set host [HTTP::host]
}
when HTTP_RESPONSE {
if { [HTTP::header exists "Set-Cookie"] } {
extract main domain name
set domain $host
set domain_parts [split $domain "."]
set domain_parts_count [llength $domain_parts]
set reduced_domain_parts [lrange $domain_parts [expr $domain_parts_count - 3] [expr $domain_parts_count - 1]]
set new_domain "; domain="
foreach part $reduced_domain_parts {
append new_domain "."
append new_domain $part
}
get the cookies
set cookies [HTTP::header values "Set-Cookie"]
remove the old cookies
HTTP::header remove Set-Cookie
foreach cookie $cookies {
set new_cookie $cookie
add the domain at the end of each cookie
append new_cookie $new_domain
add the cookie to the response
HTTP::header insert Set-Cookie $new_cookie
}
}
}
On a test VS, this works just fine, the cookie is correctly modified, no problem.
But when we put this iRule on our production VS, our users experienced disconnections. analysing the http stream, we saw that each response contains a new Set-Cookie: BIGIPServeur=xxx that is different for the cookie in the request. we have even seen request with two BIGIPServeur cookies.
Does anyone have a clue why this happens?
Thanks a lot!
hoolioCirrostratus
That's a lot of processing. I think you could use a couple of inbuilt commands to do this much easier:when HTTP_RESPONSE { Loop through each response cookie by name foreach aCookie [HTTP::cookie names] { Set the domain on the cookie to .example.com HTTP::cookie domain $aCookie ".example.com" } }
Can you give this a try and see if it works for your two virtual servers?
Thanks, Aaron
ITThanks for the quick answer.
we have indeed simplified the irule thanks to your code, but alas we can't make it that simple. The thing is we have customers that connects to our servers via CNAME redirections, so the domain name they use is not ours, we can't hardcode it on the response. that's why we get it in the request. Is it the proper way to do so?
We may have figured what happens : we have activated this irule only for our http domain, not for the https, so the redirection messes up the cookie.
we're gonna test it again really soon in production, so if you think it won't work, let me know!- hoolioAre you trying to set the domain on response cookies to the exact requested domain from the HTTP host header or just the base domain? You could parse the domain from the requested host header value using the domain command and then use that saved value in HTTP_RESPONSE to set them.
http://devcentral.f5.com/wiki/default.aspx/iRules/domain
Also, are there any cookies being set on the HTTPS VS? If so, you should use the same iRule on both the HTTP and HTTPS VS.
Aaron