Documentation request: How do I handle a Run from Python?

[adamryczkowski]

I know how to start a Hatchet worker. Now I am trying to use it.

I am trying unsuccessfully get the answer for the following problems relating to scheduling workflow runs using Hatchet's Python SDK:

1. How do I check if the Workflow is defined on the server in the first place?
2. How do I schedule a workflow run (with passing input data)?
3. How do I check, that my run (identified by the messageID I presume) is done? (I know that hatchet supports progress updates via its streaming API, but that I will postpone once I figure out this)
4. How do I pull the results of the run?

And thank you for doing this very promising project. :-)

[adamryczkowski]

I understood, that this streaming syntax is actually the way to do:

        from hatchet_sdk import StepRunEventType
        event:StepRunEventType

        for event in self._hatchet.client.listener.stream(self._messageID):
            print(event.payload)

The problem is, that if the event does not seem to be caught if the run has already been finished before the for loop starts executing.

How do I check if the run has already been computed and get its payload? The payload is there, because it is accessible via the Web UI.

[adamryczkowski]

One would hope to have the following code do the trick:

        from hatchet_sdk import WorkflowRun

        workflow_run:WorkflowRun = self._hatchet.client.rest_client.workflow_run_get(self._messageID)

        print(workflow_run.status)

Except, that it does not. The workflow_run_get errors with

Traceback (most recent call last):
  File "/snap/pycharm-professional/384/plugins/python/helpers-pro/pydevd_asyncio/pydevd_asyncio_utils.py", line 117, in _exec_async_code
    result = func()
             ^^^^^^
  File "<input>", line 1, in <module>
  File "/home/adam/.cache/pypoetry/virtualenvs/stan-runner-1qcHgIo7-py3.12/lib/python3.12/site-packages/hatchet_sdk/clients/rest_client.py", line 58, in workflow_run_get
    return self.workflow_api.workflow_run_get(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/adam/.cache/pypoetry/virtualenvs/stan-runner-1qcHgIo7-py3.12/lib/python3.12/site-packages/pydantic/validate_call_decorator.py", line 58, in wrapper_function
    return validate_call_wrapper(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/adam/.cache/pypoetry/virtualenvs/stan-runner-1qcHgIo7-py3.12/lib/python3.12/site-packages/pydantic/_internal/_validate_call.py", line 81, in __call__
    res = self.__pydantic_validator__.validate_python(pydantic_core.ArgsKwargs(args, kwargs))
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/adam/.cache/pypoetry/virtualenvs/stan-runner-1qcHgIo7-py3.12/lib/python3.12/site-packages/hatchet_sdk/clients/rest/api/workflow_api.py", line 1476, in workflow_run_get
    response_data = self.api_client.call_api(
                    ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/adam/.cache/pypoetry/virtualenvs/stan-runner-1qcHgIo7-py3.12/lib/python3.12/site-packages/hatchet_sdk/clients/rest/api_client.py", line 269, in call_api
    response_data = self.rest_client.request(
                    ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/adam/.cache/pypoetry/virtualenvs/stan-runner-1qcHgIo7-py3.12/lib/python3.12/site-packages/hatchet_sdk/clients/rest/rest.py", line 243, in request
    r = self.pool_manager.request(
        ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/adam/.cache/pypoetry/virtualenvs/stan-runner-1qcHgIo7-py3.12/lib/python3.12/site-packages/urllib3/_request_methods.py", line 136, in request
    return self.request_encode_url(
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/adam/.cache/pypoetry/virtualenvs/stan-runner-1qcHgIo7-py3.12/lib/python3.12/site-packages/urllib3/_request_methods.py", line 183, in request_encode_url
    return self.urlopen(method, url, **extra_kw)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/adam/.cache/pypoetry/virtualenvs/stan-runner-1qcHgIo7-py3.12/lib/python3.12/site-packages/urllib3/poolmanager.py", line 433, in urlopen
    conn = self.connection_from_host(u.host, port=u.port, scheme=u.scheme)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/adam/.cache/pypoetry/virtualenvs/stan-runner-1qcHgIo7-py3.12/lib/python3.12/site-packages/urllib3/poolmanager.py", line 295, in connection_from_host
    raise LocationValueError("No host specified.")
urllib3.exceptions.LocationValueError: No host specified.

Upon inspection, the url of the underlying REST api call indeed lacks the hostname. It consists purely of the path, such as /api/v1/tenants/707d0855-80ab-4e1f-a156-f1c4546cbf52/workflow-runs/e5e3eadd-e91f-43af-a399-67c54d1aeb31.

[abelanger5]

Hey @adamryczkowski, the empty hostname likely means that you haven't set the HATCHET_CLIENT_TOKEN environment variable. And could you share the version of the Python SDK you're using? I believe we patched the py SDK recently to fix the rest_client.