Can Irule forward request after ASM block?

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1

Below is a snippet from an inquiry I received from our web developers. Matching on part of the URI is no problem, but what about forwarding the request even after blocked by the ASM?

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So the iRule would have to match on:

  • Portions of the URI that indicate this is an FNOL
  • That the ASM blocked the request

Then:

  • Forward the buffered request to a specific URL

Assumptions:

  • The iRule can buffer the request so it persists beyond the ASM block. This alone may be the show-stopper as this may be a significant performance problem.
  • The iRule can send to a different location than just allowing to pass to the back end pool members

2

“The iRule can buffer the request so it persists beyond the ASM block. This alone may be the show-stopper as this may be a significant performance problem.”

◘ I’m not entirely sure what you mean by this?

“The iRule can send to a different location than just allowing to pass to the back end pool members”

◘ You can use a ‘forward’ command, redirect, etc, after the ‘ASM::unblock’ statement.

when ASM_REQUEST_DONE {
    #log local0.debug "\[ASM::status\] = [ASM::status]"
    if { [ASM::status] equals "blocked" } {
            ASM::unblock
            log local0. "Unblocked request with ID [ASM::support_id]"
            }
}

References:

3

Thanks. Great info!