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

OpenStack Nova – installation and overview

In this post, we will look into Nova, the cloud fabric component of OpenStack. We will see how Nova is installed and go briefly through the individual components and Nova services. Overview Before getting into the installation process, let us briefly discuss the various components of Nova on the controller and compute nodes. First, there … Continue reading OpenStack Nova – installation and overview

OpenStack Keystone – a deep-dive into tokens and policies

In the previous post, we have installed Keystone and provided an overview of its functionality. Today, we will dive in detail into a typical authorization handshake and take you through the Keystone source code to see how it works under the hood. The overall workflow Let us first take a look at the overall process … Continue reading OpenStack Keystone – a deep-dive into tokens and policies

Automating provisioning with Ansible – working with inventories

So far, we have used Ansible inventories more or less as a simple list of nodes. But there is much more you can do with inventories - you can assign hosts to groups, build hierarchies of groups, use dynamic inventories and assign variables. In this post, we will look at some of these options. Groups … Continue reading Automating provisioning with Ansible – working with inventories

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