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I have a Pyramid application which I can start using pserve some.ini. The ini file contains the usual paste configuration and everything works fine. In production, I use uwsgi, having a paste = config:/path/to/some.ini entry, which works fine too.

But instead of reading my configuration from a static ini file, I want to retrieve it from some external key value store. Reading the paste documentation and source code, I figured out, that there is a call scheme, which calls a python function to retrieve the "settings".

I implemented some get_conf method and try to start my application using pserve call:my.module:get_conf. If the module/method do not exist, I get an appropriate error, so the method seems to be used. But whatever I return from the method, I end up with this error message:

AssertionError: Protocol None unknown

I have no idea what return value of the method is expected and how to implement it. I tried to find documentation or examples, but without success. How do I have to implement this method?

Achim
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    pserve expects an ini file as parameter. The startup pocess (what happens when you do ``pserve xyz.ini``) is [here](http://docs.pylonsproject.org/projects/pyramid/en/latest/narr/startup.html). AFAIK ``call:`` protocol is used to load the application (In the ``use=`` line in the config). It doesn't just return the settings but actually initializes the app (calls the ``config.load_wsgi_app()`` method). Your question is not clear to me - Do you want to get the ini file dynamically? or some app related settings in the ini file dynamically? – RedBaron Nov 30 '15 at 10:58
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    Also I think the protocol mentioned in the error should be one of those mentioned [here](http://pythonpaste.org/deploy/#defining-factories) – RedBaron Nov 30 '15 at 11:04
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    And the error line is (I think) [here](https://bitbucket.org/ianb/pastedeploy/src/f30a7d518c6a79fcddfbe3f622337f81e41cb6a5/paste/deploy/loadwsgi.py?at=default&fileviewer=file-view-default#loadwsgi.py-148) – RedBaron Nov 30 '15 at 11:16

1 Answers1

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While not the answer to your exact question, I think this is the answer to what you want to do. When pyramid starts, your ini file vars from the ini file just get parsed into the settings object that is set on your registry, and you access them through the registry from the rest of your app. So if you want to get settings somewhere else (say env vars, or some other third party source), all you need to do is build yourself a factory component for getting them, and use that in the server start up method that is typically in your base _ _ init _ _.py file. You don't need to get anything from the ini file if that's not convenenient, and if you don't, it doesn't matter how you deploy it. The rest of your app doesn't need to know where they came from. Here's an example of how I do this for getting settings from env vars because I have a distributed app with three separate processes and I don't want to be mucking about with three sets of ini files (instead I have one file of env vars that doesn't go in git and gets sourced before anything gets turned on):

# the method that runs on server startup, no matter
# how you deploy. 
def main(global_config, **settings):
""" This function returns a Pyramid WSGI application."""

    # settings has your values from the ini file
    # go ahead and stick things it from any source you'd like
    settings['db_url'] = os.environ.get('DB_URL')
    config = Configurator(
        settings=settings,
    # your other configurator args
    )
    # you can also just stick things directly on the registry
    # for other components to use, as everyone has access to
    # request.registry. 
    # here we look in an env var and fall back to the ini file
    amqp_url = os.environ.get('AMQP_URL', settings['amqp.url'] )
    config.registry.bus = MessageClient( amqp_url=amqp_url )

    # rest of your server start up code.... below
Iain Duncan
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