Forum Discussion

johnmervin_4578's avatar
johnmervin_4578
Icon for Altostratus rankAltostratus
May 31, 2017

http redirect irule

I am working on a irule which basically strips "/abchef" on the URI before loadbalancing to a pool here is my rule, the issue is if I remove "log local0" or "log" from this rule it did not work, is there a better way to do it

when HTTP_REQUEST { 

        if { [HTTP::host] contains "testlab.john.com" and [HTTP::uri] starts_with "/abcdef/api/" }
        {
                    log local0[substr [HTTP::uri] 7]

pool testlab } }

application delivery
iRules
  • cjunior's avatar
    cjunior
    Icon for Nacreous rankNacreous
    May 31, 2017

    Hi, I'm not sure what you need. You just need to log:

    when HTTP_REQUEST {
    if { [HTTP::host] contains "testlab.john.com" and [HTTP::uri] starts_with "/abcdef/api/" } {
        log local0. "[substr [HTTP::uri] 7]"
        pool testlab
    }
}

    or you need to strip and rewrite uri before send to a server:

    when HTTP_REQUEST {
    if { [HTTP::host] contains "testlab.john.com" and [HTTP::uri] starts_with "/abcdef/api/" } {
        log local0. "[substr [HTTP::uri] 7]"
        HTTP::uri [substr [HTTP::uri] 7]
        pool testlab
    }
}

    Regards.

  • cjunior's avatar
    cjunior
    Icon for Nacreous rankNacreous
    Jun 01, 2017

    John, I still can't see when are removing the complete log statement line, the iRule stops to work. But, if you are just trying to run "[substr [HTTP::uri] 7]" on this line, it's really wrong thing. You need to store back on HTTP::uri.

    HTTP::uri [substr [HTTP::uri] 7]
pool testlab

    This way, on client side the URI should be: 

    /abcdef/api/
    , and on server side, the URI should be: 
    /api/

    Anyway, If you are facing issue when you do strip to uri value, and the traffic have an unexpected redirection because of the irule 1 execution, you can try to set priority to this irule. This way, it will execute before the iRule that you are rewriting the uri. e.g.

    irule 1
when HTTP_REQUEST priority 300 { 
    if { [HTTP::host] contains "testlab.john.com" and [HTTP::uri] starts_with "/api/" }
    {
        HTTP::redirect "https://f5.com[HTTP::uri]"
    }
}

irule 2
when HTTP_REQUEST {
    if { [HTTP::host] contains "testlab.john.com" and [HTTP::uri] starts_with "/abcdef/api/" } {
        HTTP::uri [substr [HTTP::uri] 7]
        pool testlab
    }
}

    I think I have no more ideas to this.

    Respectfully.