The purpose of this iRule is to create a method of load balancing via the URI that is fully dynamic and never requires updating. Example: The URL https://briandeitch.com/gateway/ should be load balanced to the pool pool_gateway The URL https://briandeitch.com/pictures/ should be load balanced to the pool pool_pictures Here is the old iRule:
when HTTP_REQUEST { switch -glob [string tolower [HTTP::path]] */gateway/ { pool pool_gateway } */pictures/ { pool pool_gateway } } }
In the past, every time I had a new URL, I would have to modify the iRule and create the new pool. If I need to add https://briandeitch.com/family/, I would have to modify the iRule:
when HTTP_REQUEST { switch -glob [string tolower [HTTP::path]] */gateway/* { pool pool_gateway } */pictures/* { pool pool_gateway } */family/* { pool pool_family } } }
By using the iRule below, pool selection will happen automatically based on the URI.
when HTTP_REQUEST { # Grab the 1st folder after the hostname set lbfolder [string tolower [URI::path [HTTP::uri] 1 1]] # Strip out the "/" set lbfolder pool_[string trim $lbfolder "/"] # log local0. "testing01 $lbfolder" if { [catch {pool $lbfolder} exc] } { # If a client sends a uri that does not match a pool, send to default pool or throw message #pool default HTTP::respond 200 content "No matching pool for that URI" persist cookie insert pr_cookie_insert } }
By using this iRule, I will never have to update the iRule again. Once I add the new pool, I’m done.
You may also download a txt version of the iRule here.
Regards,
BD