pull model from server

Rasa Core version: 0.13.2

Python version: 3.6

Operating system (windows, osx, …): Ubuntu 16

Issue:

the method _pull_model_and_fingerprint return always a etag, even the last one is not changed.

    if response.status_code in [204, 304]:
        logger.debug("Model server returned {} status code, indicating "
                     "that no new model is available. "
                     "Current fingerprint: {}"
                     "".format(response.status_code, fingerprint))
        return response.headers.get("ETag")

The returned etag will trigger the updating of agent later in _update_model_from_server:

new_model_fingerprint = _pull_model_and_fingerprint(
        model_server, model_directory, agent.fingerprint)
    if new_model_fingerprint:
        domain_path = os.path.join(os.path.abspath(model_directory),
                                   "domain.yml")
        domain = Domain.load(domain_path)
        policy_ensemble = PolicyEnsemble.load(model_directory)
        agent.update_model(domain, policy_ensemble, new_model_fingerprint)

This will make an File not found error as no zipped model has been pulled from server, but _update_model_from_server tries to load the model in a non-existing tmp directory.

Or did I missed something ?

Content of domain file (if used & relevant):

[jeanveau]

I just create a pull request to fix this bug, please check

[akelad]

sounds great 😃