Coding

48 posts

Keycloak with PostgreSQL-HA on Kubernetes

This is a follow-up to my previous article on how to setup a Keycloak instance with Postgres on k8s. Surprisingly, it was quite popular on HackerNews and received lots of comments. Among them were questions regarding high-availability and failure resistance. In the original article I described a fairly simple setup running Keycloak and Postgres pods which were accessing manually created PersistenceVolumes and Claims. I showed how to do all that both with handcrafted YAMLs as well as with Helm charts. There is also a repository containing YAMLs and configurations, so before you start working with the solution described here, maybe […]

Keycloak with PostgreSQL on Kubernetes

In this article we will learn how to deploy Keycloak with PostgreSQL on Kubernetes. We will first do everything manually with separate YAMLs and then later with Helm. Our k8s environment will run in Kind, which is an easy to use k8s variant for local expermentation. The sources are located here. Keycloak Keycloak is one of the most popular open-source Identity and Access Management providers. It can run in various environments, from small shops up to giant data centers. Although this article isn’t about IAM’s in general and how to use them, let’s provide a simple definition just to make […]

GnuCOBOL on Windows – from Compilation to HelloWorld

COBOL is an old language from 1959, partly based on programming language work by Grace Hopper, with a strong focus on business applications. There are still many COBOL programs running around the globe, mostly in banking, insurance, and governments. Although frequently criticized as a sloppy designed, non-computer-scientific, and a badly structured language in general, COBOL still dominates in many fields that affect our daily lives. For example, when you interact with your bank account there’s almost always some piece of COBOL code quietly working along. When you deal with any kind of “bureaucracy” there’s almost always some complex COBOL-based batch-process that […]

Reactive apps with Angular & ngrx

Building web apps by following certain reactive patterns and conventions is a proven way of delivering stable and scalable software. The tool set we’ll be talking about is known under the acronym ngrx and it comprises of several sub-packages. Here I’ll refer to them simply as ‘ngrx’ but, please, take into account that there are many of them with the same prefix, like ngrx/state, ngrx/effects, ngrx/core and so on. We’ll develop a simple Angular 4.x app showing a table in master-detail design. The UI plugin used to create the table is the nice datatables.net library.   The sources can be found here.  A working demo […]

WebVR with A-Frame & Angular

The goal of this article is to describe the inner workings of an environment for WebVR components that’s based on A-Frame & Angular 2. As the design and maintenance of components like these are complex and repetitive tasks it’d be of much help to have a mechanism to offload the boilerplate like base structures, build-scripts, polyfills and other ‘usual suspects’ found in almost every web-oriented project. This is the main reason why this project exists. I wanted to have a tool-set that could not only help me create nice WebVR components but also deliver them easily by following best practices and accepted Web Standards. The […]

Thrill – Big Data Processing with C++

Yesterday, I discovered an experimental Big Data processing framework written in C++ called Thrill. As most of you surely know, the well-known frameworks of this kind are mostly based on JVM, like Apache Spark or Apache Flink. This, of course, has many advantages, like easily accessible interfaces and a more domain-oriented approach, as we don’t have to deal with “Ceremony Code” or any internals that don’t touch our domain logic. However, everything comes at a cost and utilizing a VM is a price to be paid no matter how optimized your code is. It’s no wonder these projects often resort to […]

Intro to Angular 2 – Part 6 – ServiceWorkers

In the last installment we learned how to run JavaScripts over different threads by using WebWorkers. This time we’ll go a few steps further and learn how to use ServiceWorkers to achieve not only separation of code but also to build up client-side proxies. These proxies are the most important building blocks of so-called Progressive Web Apps as they allow web apps to function under rough conditions like slow bandwidths or broken connections. ServiceWorkers can also be used for push-based services or background synchronization as they run completely detached from the Browser DOM. A ServiceWorker is basically a SharedWorker with super-powers. However, the […]