[Openstack] Openstack Nova/Quantum :; api-paste.ini file

Kevin L. Mitchell kevin.mitchell at rackspace.com
Thu Dec 6 17:27:58 UTC 2012

Honestly, I don't understand your questions; I figured the documentation
I pointed you to would answer them, and the fact it doesn't suggests
that you're not asking what I thought you were asking.  Maybe an
approach from the beginning:

Nova, Quantum, Glance, Keystone, etc. all have, as components, a REST
API.  They use the PasteDeploy package to build this API; PasteDeploy
provides a means of building a WSGI stack (WSGI is the Python Web Server
Gateway Interface, an interface by which HTTP requests can be presented
to a Python application; it allows for not only an application, but also
a set of "middleware", which wraps the application and can provide

The various configuration files you reference are used by PasteDeploy to
construct the WSGI stack for the API; that is, the configuration file
tells PasteDeploy that the nova-api service is composed of a specified
controller, wrapped by middleware that implements exception trap
translation, authentication checks, ratelimit enforcement, etc., all in
a specific order.  In essence, the configuration file acts sort of like
code, rather than configuration; it expresses the structure of the final
application.  (Although configuration can also be expressed in the file,
we're trying to avoid that, so that we don't mix configuration with

Does that help you some?

On Thu, 2012-12-06 at 22:29 +0530, Trinath Somanchi wrote:
> [1] What is the significance of the api-paste.ini file in the
> configuration of nova/quantum and other modules of ipenstack?
> [2] How do the modules use these API configuration options? How they
> are used different from normal ".conf" files?

Kevin L. Mitchell <kevin.mitchell at rackspace.com>

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