I wanted to repurpose apps/demo/aws_iot/shadow such that the wait for AWS events (for subscribe to a thing delta) is returned in a callback ...
Also, publish requires a context as well.
In the demo/aws_iot/shadow, there is a while(1) loop and a semaphore to wait upon in order to publish changes to LED status.
How do I make asynchronous called to mqtt_publish and get async notifications for mqtt_subscribe without the while(1) loop ... Also, the parsing of the x509 certificate from PEM to DER takes more time and is not at all synchronous and sometimes does not run to completion before the mqtt_conn_open is called ... This results in 3 retries and sometimes even a failure to connect.