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

Learn how to create and use Python Decorators

Python is an amazing language to program in. Its easy to get started and you can dig as deep as you want. Today I’m going to show you how to use Python Decorators.

Continue reading

Posted in Open Source, Python | Comments Off

Working with the Python Keystone Client with OpenStack Keystone

Keystone is an OpenStack project that provides Identity, Token, Catalog and Policy services for use specifically by projects in the OpenStack family. For the python-keystoneclient there’s a Python API (the keystoneclient module), and a command-line script (keystone). I’m going to cover the Python API part today.

Continue reading

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

Tutorial: Go (Golang) Pointers in 5 Minutes

In my previous Go articles I showed you how to setup Go on Ubuntu as well as how to create a couple different REST projects (here and here). Today, I’m going to go over how to use pointers and references in Go.

Continue reading

Posted in Go, Open Source | 2 Comments

Tutorial: Building Middleware in Python with WebOb and Paste

Roaming about the Internet looking at OpenStack information I stumbled upon a slideshow that has some good starter code for a simple Python WSGI application using WebOb and Paste. I decided to take what the author started there and turn it into a simple tutorial for those new to WebOb and Paste.

In today’s article we will walk through how to setup and configure your WSGI application to use these technologies to build a very simple Middleware filter.

Continue reading

Posted in Open Source, Python | 1 Comment