iRule for Version check with dependent pool selection

I may not have fully understood but here is a simple iRule I've put together which may work, or at least give you an idea of where to go next. Unfortunately there is no why to interrogate the result of a health monitor by an iRule but you can can determine if you have active members - which is reliant on the monitor.

From what I understand, incoming requests will have the version number in the URI and from that you want to dynamically select the pool or pool member.

If you have a one to one relationship between pool names and version you can dynamically select the pool based on URI - you will however have to maintain a different pool for every new version.

when HTTP_REQUEST {

    set defaultPool "MY_DEFAULT_POOL_NAME"
     use getfield to pick 'field1'of the URI https://host.com/field1/field2
    set dynamicPool [getfield [HTTP::uri] "/" 2]
    log local0. "Pool: $dynamicPool derived from URI"

    if {$dynamicPool ne ""} {
         place commands using dynamicPool in catch statement
         this will silently catch the TCL error in the event 
         the pool doesn't exist
        if {[catch {
            if {[active_members $dynamicPool] > 0} {
                log local0. "load balancing to pool: $dynamicPool"
                pool $dynamicPool
            }
        } catchErr ]} {
             select default pool if dynamicPool doesn't exist
            log local0. "unable to select pool based on URI, will use default  - error: $catchErr'"
            pool $defaultPool
        }
    } else {
        log local0. "Error - pool value empty, setting to default"
        pool $defaultPool
    }

}

Please note this iRule has only tested for syntax errors