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

Python up an EKS cluster – part I

When you want to try out Kubernetes, you have several choices. You can install Kubernetes in a cluster, ¬†install it locally using Minikube, or use one of the Kubernets offerings of the major cloud providers like AWS, GCP or Azure. In this post, we set up a Kubernetes cluster on Amazons EKS platform. As I … Continue reading Python up an EKS cluster – part I

Factoring integers on a quantum computer with Qiskit

After all the work done in the previous posts, we are now ready to actually implement Shor's factoring algorithm on a real quantum computer, using once more IBMs Q Experience and the Qiskit framework. First, recall that Shor's algorithm is designed to factor an integer M, with the restriction that M is supposed to be … Continue reading Factoring integers on a quantum computer with Qiskit

Implementing the quantum Fourier transform with Qiskit

The quantum Fourier transform is a key building block of many quantum algorithms, from Shor's factoring algorithm over matrix inversion to quantum phase estimation and simulations. Time to see how this can be implemented with Qiskit. Recall that the quantum Fourier transform (or, depending on conventions, its inverse) is given by $latex |x \rangle \mapsto … Continue reading Implementing the quantum Fourier transform with Qiskit