Forum Discussion

Nimbostratus

Nov 25, 2014

ASM_REQUEST_DONE and HTTP/1.1 POST request with Expect: header

Hello! Can somebody tell me how i could check if my iRule is running in the right "context" for checking HTTP::uri during a ASM_REQUEST_DONE event? My problem is, that we receive HTTP/1.1 r...

Andreas_Lamprec

Nimbostratus

Nov 26, 2014

Thanks for you answer!

So if i understood you right, then HTTP_REQUEST event will not be raised for the "second" part of the HTTP/1.1 Post request?

How about following code:

when HTTP_REQUEST {
  if { [HTTP::header exists "Expect"] } {
     set expect_flag 1
  } else {
     set expect_flag -1
  }
} 

when ASM_REQUEST_DONE {

  if( expect_flag != 0 } {
     do something to check if the request shall be unblocked
     and set "shall_be_unblocked" to 1

     unblocking of all "normal" requests
    if { shall_be_unblocked == 1 && expect_flag < 0} { ASM::unblock }

     unblocking of POST requests with Expect header set
    if { shall_be_unblocked == 1 && expect_flag > 0 } { set expect_flag 0; ASM::unblock }
  }
}

This way, the actual POST request could be unblocked if nessesary, but the "second" part of the POST will not be handled by ASM_REQUEST_DONE

Drew_128543
Nimbostratus
Nov 26, 2014
My best guess at what is happening is that the ASM needs to see the entire POST for the ASM::unblock to work. By stripping the expect header, it forces the client to send the rest of the POST (after that ~3 second delay) before the ASM_REQUEST_DONE gets called. If you leave the Expect header in place, the ASM_REQUEST_DONE gets called before it has the entire post, so the HTTP::uri calls throw the context error, and the ASM::unblock fails to work. I am unsure how to get this work with leaving the Expect: 100-continue header in place (after I stripped the header out I had to move on to other tasks and was unable to continue testing).