I'm afraid this approach will not guarantee reliable solution - port will be released between acquisition and real use, and it heavily depends on how we use these properties - for example we have code like this:

def kafka_produce(kafka_cluster, topic, messages, timestamp=None, retries=15):
    logging.debug(
        "kafka_produce server:{}:{} topic:{}".format(
            "localhost", kafka_cluster.kafka_port, topic
        )
    )
    producer = get_kafka_producer(
        kafka_cluster.kafka_port, producer_serializer, retries
    )
    for message in messages:
        producer.send(topic=topic, value=message, timestamp_ms=timestamp)
        producer.flush()

notice kafka_port is used in logging first...

I agree, it's better, but not 100% reliable.

It's much better at least by reducing the time between assigning *_port and using it. Another point, we don't collect every possible port at __init__ anymore, and reserve them only on demand