Need help with iRule based on host and path

Question

Hello all.I am trying to create an iRule that will choose a specific pool based on host and path. I tried the following code:when HTTP_REQUEST {&nbsp; if { [HTTP::host] equals "hostname_a"} {&nbsp; &nbsp; if { [HTTP::path] equals "/path" } {&nbsp; &nbsp; &nbsp; pool pool_a&nbsp; &nbsp; &nbsp; &nbsp; log local0. "URL : [HTTP::host][HTTP::uri] entered"&nbsp; &nbsp; }&nbsp; }&nbsp; if { [HTTP::host] equals "hostname_b"} {&nbsp; &nbsp; if { [HTTP::path] equals "/path" } {&nbsp; &nbsp; &nbsp; &nbsp; pool pool_b&nbsp; &nbsp; &nbsp; &nbsp; log local0. "URL : [HTTP::host][HTTP::uri] entered"&nbsp; &nbsp; }&nbsp; }&nbsp;}According to Big-IP stats, the iRule gets executed but it doesnot direct the call to the pool (pool stats shows 0) specified although logging is invoked and I get the URL in the ltm logs.Right after this script there is another one which gets executed and works as it should be. It specifies even more conditions for a series of pools and if none is matched then directs the call to the default pool specified there.The problem is with the first one. I would like it to be executed and unless there is a match, then it should proceed to executing the second one.&nbsp;If you can give me some advice it would be highly appreciated. Thank you.

adminas · Accepted Answer

Finally, problem solved! The reason was the order of execution for the 2 scripts. I donot really understand why this happens but when I placed the script in second place, everything is executed as expected. If you have any ideas please let me know.The problematic order which doesnot work is shown below:First script:when HTTP_REQUEST {&nbsp; if { [HTTP::host] equals "hostname_a"} {&nbsp; &nbsp; if { [HTTP::path] equals "/path" } {&nbsp; &nbsp; &nbsp; pool pool_a&nbsp; &nbsp; &nbsp; &nbsp; log local0. "URL : [HTTP::host][HTTP::uri] entered"&nbsp; &nbsp; }&nbsp; }&nbsp; if { [HTTP::host] equals "hostname_b"} {&nbsp; &nbsp; if { [HTTP::path] equals "/path" } {&nbsp; &nbsp; &nbsp; &nbsp; pool pool_b&nbsp; &nbsp; &nbsp; &nbsp; log local0. "URL : [HTTP::host][HTTP::uri] entered"&nbsp; &nbsp; }&nbsp; }&nbsp;}&nbsp;Second script:when HTTP_REQUEST {if {[HTTP::has_responded]}{return}&nbsp; &nbsp; switch -glob [string tolower [HTTP::path]]&nbsp; &nbsp; {........&nbsp;&nbsp;&nbsp; }&nbsp;&nbsp;&nbsp; default&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; switch [string tolower [HTTP::host]]&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; {&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; "hostname_a"&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;pool pool_c&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; persist none&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }.........&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; default&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; {&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; pool_z&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }......Anyway, thank you all very much for your time.

joselabra · Answer

Hii how r u?Why you dont use a Policy? Its more simple&nbsp;
check this articlehttps://my.f5.com/manage/s/article/K15097
&nbsp;

adminas · Answer

Hi. I am fine and hope the same for you!

Thank you very much for your reply but the are already 3 working iRules that I cannot remove / convert and I need just an extra iRule to be executed in the beggining and move to the next script if no match is found. Its a production system and I cannot really experiment as I have no experience in policies.

joselabra · Answer

And if you captured the traffic with tcpdump and test the iRule, you see the LB correctly?I remember a scenario with the same issue, the pool dont show the stats, but the LB its working.
&nbsp;
if was the case, open a ticket to support for more detail

zamroni777 · Answer

"equals" means exact match.maybe what you need is starts_with.https://clouddocs.f5.com/api/irules/starts_with.htmlfor testing, you can install virtualedition with trial license or create test vserver

aswin_mk · Answer

Can u try with below example, u can add specific uri and host name. u can edit it based on your different host and path&nbsp;when HTTP_REQUEST {&nbsp; &nbsp; # Define pool selection based on host and path&nbsp; &nbsp; if { [HTTP::host] eq "example.com" } {&nbsp; &nbsp; &nbsp; &nbsp; if { [HTTP::uri] starts_with "/app1" } {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; pool pool_app1&nbsp; &nbsp; &nbsp; &nbsp; } elseif { [HTTP::uri] starts_with "/app2" } {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; pool pool_app2&nbsp; &nbsp; &nbsp; &nbsp; } else {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; pool default_pool&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; } elseif { [HTTP::host] eq "anotherexample.com" } {&nbsp; &nbsp; &nbsp; &nbsp; if { [HTTP::uri] starts_with "/service1" } {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; pool pool_service1&nbsp; &nbsp; &nbsp; &nbsp; } elseif { [HTTP::uri] starts_with "/service2" } {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; pool pool_service2&nbsp; &nbsp; &nbsp; &nbsp; } else {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; pool default_pool&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; } else {&nbsp; &nbsp; &nbsp; &nbsp; # Fallback to a default pool if no match is found&nbsp; &nbsp; &nbsp; &nbsp; pool default_pool&nbsp; &nbsp; }}

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Need help with iRule based on host and path

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