An Introduction to OpenStack TaskFlow with Python

OpenStack TaskFlow is a library to complete workflows/tasks in a highly available manner. The TaskFlow wiki is located here and contains a pretty good overview. In the simplest terms: Taskflow is used to organize actions into lightweight task objects which are then linked together as an ordered sequence by a flow. This will be a quick overview summarizing the information already out there and doing a few examples to get the basics down.

Continue reading

Posted in Open Source, OpenStack, Python | 1 Comment

Three ways to get a Scoped Token from OpenStack Keystone

Let’s take a look at three (very basic) ways to get a scoped token from Keystone (the OpenStack Identity Project). Keep in mind that these are just a few ways you can go about this. Before trying this out make sure you have a Keystone endpoint to test against and if you don’t you can follow my tutorial on how to get Keystone (Havanna) up and running on Ubuntu.

Continue reading

Posted in Open Source, OpenStack, Python, REST | Comments Off

Learning Python WSGI and Building Simple Middleware

WSGI stands for Web Services Gateway. You can read the original PEP 333 as well as the updated PEP 3333 which includes community errata, addenda, and clarifications, as well as better Python 3 support. Today, I’m going to show you how to create and run some simple WSGI examples as well as some basic middleware.

Continue reading

Posted in Open Source, Python | Comments Off

Trying out OpenStack with DevStack

DevStack offers shell scripts to build OpenStack development environments. Getting up and running with DevStack is reasonably easy, however, there are a couple things to know if you are new to it. I’m going to cover the basics on how to get an OpenStack environment up and running using DevStack on a Cloud VM.

Continue reading

Posted in Open Source, OpenStack | Comments Off

Building a (simple) REST application with Pecan (pecanpy)

Pecan is a lean Python web framework inspired by CherryPy, TurboGears, and Pylons (Pyramid). According to the main Pecan documentation page: “Pecan was created to fill a void in the Python web-framework world – a very lightweight framework that provides object-dispatch style routing. Pecan does not aim to be a “full stack” framework, and therefore includes no out of the box support for things like sessions or databases (although tutorials are included for integrating these yourself in just a few lines of code). Pecan instead focuses on HTTP itself”. Today, I’m going to focus on a few REST capabilities of Pecan.

Continue reading

Posted in Open Source, OpenStack, Python, REST | 4 Comments

Getting started with OpenStack Oslo Config (oslo.config)

The Oslo configuration API supports parsing command line arguments and .ini style configuration files. Its probably safe to say that all OpenStack projects use oslo.config. Make sure to also check out the oslo.config documentation on the OpenStack documentation website.

Continue reading

Posted in Open Source, OpenStack, Python | 2 Comments

Working with OpenStack Marconi (Message Queuing Service) with cURL and Python

This article is a follow-up to my previous post Installing OpenStack Marconi (Message Queuing Service) on Ubuntu 12.04 LTS. With this article I’ll show you some simple ways you can interact with Marconi. Marconi is one of the newer projects added to the OpenStack umbrella and like the others is written in Python. I suggest you go through my previous article to get Marconi up and running on a test server.

Continue reading

Posted in Open Source, OpenStack, Python | Comments Off

Installing OpenStack Marconi (Message Queuing Service) on Ubuntu 12.04 LTS

OpenStack Marconi is a message queuing service, if you’ve used a message queue before like Amazon SQS, RabbitMQ, etc. then you’ll be familiar with the concepts of Marconi. Marconi is an OpenStack project currently in the incubation phase. Today I’ll focus on setting up a development server running Marconi. Keep in mind that this will not be a production server installation, just something to mess around with and kick the tires so to speak.

Recently I updated the Marconi Readme with similar instructions however in this article I’ll add more details for those new to Marconi or setting up this kind of thing in general.

Continue reading

Posted in Open Source, OpenStack, Ubuntu | Comments Off

Setting up OpenStack (Havana) Keystone in ten easy steps on Ubuntu 12.04 LTS

I’m going to go through the steps required to setup OpenStack’s Identity Service Keystone on Ubuntu 12.04. I’ll assume you already have Ubuntu 12.04 LTS up and running.

Continue reading

Posted in Open Source, OpenStack, Python | 1 Comment

Running a Python (or almost anything) as a service with automatic restart via Upstart

Pretty often I run into a situation where I’d like a Linux application I’ve created to run as a service. Basically, run my Python, Go (GoLang), Ruby, etc. application on start-up and respawn it if it gets any kind of termination/kill signal. Today I’ll show you how to do this with a simple Python Tornado application.

Continue reading

Posted in Open Source, Python, Tornado, Ubuntu | 1 Comment