OpenStack Nova – deep-dive into the provisioning process

In the last post, we did go through the installation process and the high-level architecture of Nova, talking about the Nova API server, the Nova scheduler and the Nova agent. Today, we will make this a bit more tangible by observing how a typical request to provision an instance flows through this architecture. The use … Continue reading OpenStack Nova – deep-dive into the provisioning process

WSGI, middleware, PasteDeploy and all that

When you are a Python programmer or study open source software written in Python, you will sooner or later be exposed to the WSGI standard and to related concepts like WSGI middleware. In this post, I will give you a short overview of this technology and point you to some additional references. What is WSGI? … Continue reading WSGI, middleware, PasteDeploy and all that

Automating provisioning with Ansible – variables and facts

In the playbooks that we have considered so far, we have used tasks, links to the inventory and modules. In this post, we will add another important feature of Ansible to our toolbox - variables. Declaring variables Using variables in Ansible is slightly more complex than you might expect at the first glance, mainly due … Continue reading Automating provisioning with Ansible – variables and facts

Managing traffic with Kubernetes ingress controllers

In one of the previous posts, we have learned how to expose arbitrary ports to the outside world using services and load balancers. However, we also found that this is not very efficient - in the worst case, the number of load balancers we need equals the number of services. Specifically for HTTP/HTTPS traffic, there … Continue reading Managing traffic with Kubernetes ingress controllers

Quantum teleportation

Quantum states are in many ways different from information stored in classical systems - quantum states cannot be cloned and quantum information cannot be erased. However, it turns out that quantum information can be transmitted and replicated by combining a quantum channel and a classical channel - a process known as quantum teleportation. Bell states … Continue reading Quantum teleportation