Websocket "Webhook" not working

[matgnt]

Hi all,

from the code in server.py I found that websockets are a way to receive push notifications. I very much like this idea! After playing around with it a little, I could only receive the very first message after I connected to the /ws endpoint. 1 message on the "settings" topic. Right after this message, the connection got closed.

After debugging aca-py a bit, I can locate the issue now.
I used version 0.4.1, but no change in server.py since then.

send = loop.create_task(queue.dequeue(timeout=5.0))
https://github.com/hyperledger/aries-cloudagent-python/blob/master/aries_cloudagent/admin/server.py#L364

The timeout can cause an asyncio.TimeoutError exception.
(raised in basic.py)

If that happens, it's not detected until this call:
msg = send.result()
https://github.com/hyperledger/aries-cloudagent-python/blob/master/aries_cloudagent/admin/server.py#L380

This call re-raises the exception from inside the task and causes the whole loop to stop and jump to the finally block and cleans up the websocket queue.
Websocket closed now and it can't be used in send_webhook any more.
https://github.com/hyperledger/aries-cloudagent-python/blob/master/aries_cloudagent/admin/server.py#L427

I see a few options:

• catch the asyncio.TimeoutError near the send.result() call (or somewhere later, still inside the loop) or
• test for send.exception() before the result() call

Any thoughts on this?

Thanks and have a nice evening,
Matthias

[swcurran]

@andrewwhitehead - can you please take a look at this? Thanks!