How to redirect using F5 iRules with a variable in the URL - redirect

Question

Hi I'm new to F5 iRule.
I'm trying to redirect
https://website1.com/userid=1234
to
https://website2.com/userid=1234
such that whatever value the userid may have will be carried over after redirection.
I'm thinking userid value should be set to a variable.
Can someone share what code to use? Thanks!
So https://website1.com/userid=8888 should go to https://website2.com/userid=8888 and so on.

Answer 1

You shouldn't need a variable if that pattern is consistent. A simple rule would be:
when HTTP_REQUEST {
if { [HTTP::host] eq "website1.com" } {
HTTP::redirect https://websitesite2.com[HTTP::uri]
}
}
However, if you are on v11.4+, you really should use a local traffic policy for this as it is more performant as a built-in feature of TMOS.
ltm policy sample_site_redirect {
controls { forwarding }
last-modified 2018-12-20:09:33:02
requires { http }
rules {
full_uri_redirect {
actions {
0 {
http-reply
redirect
location tcl:https://website2.com[HTTP::uri]
}
}
conditions {
0 {
http-host
host
values { website1.com }
}
}
}
}
status published
strategy first-match
}
if all traffic to the virtual server this rule or policy is attached to is intended for website1 only, you can eliminate those conditions. I didn't want to assume. If it's only the URI starting with /user= that you want to match, and redirect on, you can do that this way:
when HTTP_REQUEST {
if { ([HTTP::host] eq "website1.com") && ([string tolower [HTTP::uri]] starts_with "/user=") } {
HTTP::redirect https://website2.com[HTTP::uri]
}
}