iRule for SideBand connection

You can do it that way, but it might be cleaner and more supportable to use an opensource ICAP server, which BigIP already has built-in support for through request-adapt and response-adapt profiles.

With ICAP, the bigip takes the http request, wraps it up inside an ICAP header, sends that off to the ICAP server, which can modify or block the request. If allowed/modified, the request is sent off to the pool, the reply comes back, again passes through the ICAP server, and then finally back to client.

ICAP is intended for content filtering, for example blocking certain websites, but it might suit your needs here also.

Thank you Ian, can you provide an example how to convert user credentials into JSON and sent to sideband server. Unfortunately I didn't find any examples how to do it and can't use ICAP. I will be grateful.

Did you look at sideband examples like this one? They all seem to be quite straightforward.

Did you look at sideband examples like this one? They all seem to be quite straightforward.