Default implementation of Service.run() yields None which causes an error

[azawlocki]

Consider the following script:

import ...  # omitted

class SimpleService(Service):
    @staticmethod
    async def get_payload():
        # this could be any valid image 
        return await vm.repo(
            image_hash="8b11df59f84358d47fc6776d0bb7290b0054c15ded2d6f54cf634488",
            min_mem_gib=0.5,
            min_storage_gib=2.0,
        )
    # start(), run() and shutdown() are inherited from Service

 async def main():
     async with Golem(budget=1.0) as golem:
         cluster = await golem.run_service(SimpleService)
         while True:
             if cluster.instances:
                 print(f"Service is {cluster.instances[0].state.value}")
             await asyncio.sleep(5)

enable_default_logger()

loop = asyncio.get_event_loop()
task = loop.create_task(main())
loop.run_until_complete(task)

It's output shows that the default Service.run() method causes an error since it yields None:

[2021-06-08 23:25:39,711 INFO yapapi.summary] Received proposals from 1 provider so far
[2021-06-08 23:25:39,715 INFO yapapi.summary] Received proposals from 2 providers so far
[2021-06-08 23:25:40,369 INFO yapapi.summary] Agreement proposed to provider 'provider-1'
[2021-06-08 23:25:40,427 INFO yapapi.summary] Agreement confirmed by provider 'provider-1'
[2021-06-08 23:25:41,189 INFO yapapi.services] <SimpleService: e4aaadd900bb42959323cf2ac32866bc> commissioned
[2021-06-08 23:25:41,191 INFO yapapi.summary] Task started on provider 'provider-1', task data: Service: SimpleService
Service is starting
Service is running
Service is running
[2021-06-08 23:25:54,819 WARNING yapapi.summary] Worker for provider 'provider-1' failed; reason: 'NoneType' object has no attribute 'timeout'
[2021-06-08 23:25:54,839 INFO yapapi.summary] Terminated agreement with provider-1
[2021-06-08 23:25:56,846 INFO yapapi.summary] Accepted invoice from 'provider-1', amount: 0.004154389926666667
Service is running
Service is running