Writing your First OpenStack Application¶

Problem description¶

Currently, OpenStack is missing documentation similar to other Python projects, that introduces a new user to the API. One well known “first app” tutorial in the Python community is the Django web framework’s tutorial.

Proposed change¶

A guide has been written by members of the Application Ecosystem WG that introduces the OpenStack API, using a non-trivial Python application that serves as a teaching tool - similar to the poll app in the equivalent Django tutorial.

Implementation¶

This book has been written for software developers who wish to deploy applications to OpenStack clouds.

We’ve assumed that the audience is an experienced programmer, but that they haven’t necessarily created an application for cloud in general, or for OpenStack in particular.

In addition to learning to deploy applications on OpenStack, the reader will also learn some best practices for cloud application development.

This tutorial actually involves two applications; the first, a fractal generator, simply uses mathematical equations to generate images. However, really, it’s just an excuse; the real application is the code that enables the reader to make use of OpenStack to run it. That application (and therefore this guide) includes:

• Creating and destroying compute resources.
• Cloud-related architecture decisions, such as microservices and modularity
• Scaling up and down to customize the amount of available resources.
• Object and block storage for persistance of files and databases.
• Orchestration services to automatically adjust to the environment.
• Networking customization for better performance and segregation.
• A few other crazy things we think ordinary folks won’t want to do ;).

The guide has been written with a strong preference for the most common API calls, so it will work across a broad spectrum of OpenStack versions. In addition, the authors have paid special attention that the first 3 sections should work almost regardless of OpenStack cloud configuration (basically Nova, Keystone and Glance are the only requirements, but neutron will be used if installed).

Dependencies¶

None

Testing¶

The guide is written in such a way that all examples can be run by the reader, and steps have been taken to verify that all content is valid.

To date, libcloud sections 1-3 have been tested by at least 7 people on 7 different clouds that the authors are aware of, and the remaining sections with samples have been tested on at least 3 different clouds.

Fog in section1 has only had testing on one cloud, and should not be published until both section 1-3 is completed as a minmum and additional testing has been performed.

The testing process for this guide is similar to the install guide. A tester should take the role of a ‘naive’ reader, following the guide’s instructions exactly with no deviation. Any instructions that did not work, or are too difficult to follow should be noted as bugs and fixed.

References¶

• [Openstack-operators] Fostering OpenStack Users
• Application Eco WG - meeting - “first app tutorial”