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someguy's avatar
someguy
Icon for Nimbostratus rankNimbostratus
Mar 06, 2014

How can I return content directly from an irule and skip LB/server interaction?

I'm trying to return a pre-defined html page directly from an F5 without hitting backend servers (DC health-check). I have come up with the below irule, but it appears to work about half of the time, the other half it hits the pool and generates a 404. Seems like this should be simple, what am I doing wrong? 

when HTTP_REQUEST {
    if {[HTTP::uri] equals "/ping.html" }
    {
        set object [class lookup "ping" "ping_objects"]
        HTTP::respond 200 content $object noserver Cache-Control No-Cache Pragma No-Cache
        event disable all
        return
    }
}
application delivery
devops
iRules
LTM

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  • Patrik_Jonsson's avatar
    Patrik_Jonsson
    Icon for MVP rankMVP
    Mar 06, 2014

    Hi mate! Event disable all would probably lead to using the default pool for all the subsequent requests in the same connection. Try removing it and it should work.

     

    /Patrik

     

  • Patrik_Jonsson's avatar
    Patrik_Jonsson
    Icon for MVP rankMVP
    Mar 06, 2014

    Hi! The connection reset is probably due to other rules executing pool selections or redirects.

    when HTTP_REQUEST {
    if {[HTTP::uri] equals "/ping.html" }
    {
        set object [class lookup "ping" "ping_objects"]
        HTTP::respond 200 content $object noserver Cache-Control No-Cache Pragma No-Cache
        set dchc 1

    }
}

    Then start all the following rules with the following if statement:

    if { [info exists blocked] && $blocked == 1 } {
    Doing nothing here because of DCHC variable being set
} else {
    Put the old iRule content here.
}

    /Patrik