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Paedrig_69869's avatar
Paedrig_69869
Icon for Nimbostratus rankNimbostratus
Sep 20, 2016

iRule to process URI and Header data groups

Hi All,

I am trying to create an iRule that will match certain URIs against a data-group to decide which pool to send it to and then if no matching URI inspect the header and check against another data-group.

I am trying to make it dynamic enough to be able to be reused in multiple environments and may have to change from using [HTTP::path] to include the VIP port number as there may be multiple virtuals on the same IP/hostname for streams matching on the same path but sent to a different pool.

when HTTP_REQUEST { 
    if { [class match [string tolower [HTTP::path]] starts_with dg_uri_pool_redirect] } {
            pool [class lookup [HTTP::path] dg_uri_pool_redirect] }
    elseif { [HTTP::header exists remote.contenttype] and [HTTP::header remote.contenttype] equals dg_header_pool_redirect } {
            pool [class lookup [HTTP::header remote.contenttype] dg_header_pool_redirect]
    }
}
application delivery
iRules

1 Reply

  • Michael_Jenkins's avatar
    Michael_Jenkins
    Icon for Cirrostratus rankCirrostratus
    Sep 20, 2016

    Apart from adding the hostname and path in your datagroup, you could use other datagroups to handle that... Untested, but perhaps something similar to this:

    when HTTP_REQUEST { 
    set hostLower [string tolower [HTTP::host]]
    set pathLower [string tolower [HTTP::path]]

     Use a datagroup matched on the host name that will give you the name of another datagroup to use to look up the pool redirect
    if { [class match $hostLower starts_with dg_host_dg_lookup] } {
        set dgName [class match -value $hostLower starts_with dg_host_dg_lookup]

         Now check the correct datagroup for the path
        if { [class match $pathLower starts_with $dgName] } {
            pool [class lookup $pathLower $dgName] 
            return
        } 

         If that didn't work, check for the header value
        if { [HTTP::header exists remote.contenttype] && [HTTP::header remote.contenttype] equals dg_header_pool_redirect } {
            pool [class lookup [HTTP::header remote.contenttype] dg_header_pool_redirect]
            return
        }
    }
}

    You'd need to add additional data-groups for each host (which includes the hostname:port)