Containers
Implémenter le motif de conception 'Strangler Fig' dans OpenShift
Le motif de conception Strangler Fig a été documenté par Martin Fowler en 2004. Il fait référence à un arbre nommé le “figuier étrangleur” qui s’appuie sur son hôte pour ses premières années de vie, jusqu’à ce que ses racines touchent le sol. Il peut ainsi se nourrir et grandir de manière autonome. Son hôte sert alors de support et finit par mourir “étranglé”. C’est une analogie avec la ré-ingénierie d’un système en production: les composants d’un monolithe sont réécrits un à un, sous forme de micro-services, à coté du système existant. Les composants du monolithe sont alors remplacés au fil de l’eau par leur équivalent micro-service. Une fois tous les composants du monolithe remplacés, il peut alors être décommissionné. La question qui m’a été posée est: est-il possible d’implémenter ce motif à l’aide des outils et fonctions d’OpenShift ? Continuer la lecture
Install Kubernetes operators in OpenShift using only the CLI
OpenShift 4 went all-in on Kubernetes operators: they are used for installation of the platform itself but also to install databases, middlewares, etc. There are more and more operators available on the Operator Hub. Most software now provide an operator and describe how to use it. Nevertheless, almost every software documentation I read so far, includes the steps to install the operator using the nice GUI of OpenShift 4. But since my OpenShift environments are provisioned by a playbook, I want to be able to install operators using the CLI only! Continuer la lecture
Airgap OpenShift Installation: move the registry created using oc adm release mirror between environments
Some customers, especially large banks, have very tight security requirements. Most of them enforce a complete disconnection of their internal networks from the Internet. When installing OpenShift in such environments (this is named “disconnected” or “airgap” installation), all the OpenShift images have to be fetched (thanks to oc adm release mirror) in a dedicated registry from a bastion host that is both on the internal network and on the Internet. Continuer la lecture
Deploying Miniflux on OpenShift
Miniflux is a minimalist, open source and opinionated RSS feed reader. There is a hosted instance available at a fair price point but wouldn’t it be cooler to host your own instance on your OpenShift cluster? Let’s do it! Continuer la lecture
Deploying Invidious on OpenShift
Invidious is an alternative frontend to YouTube that is slimmer, faster and at the same time offer more features than YouTube itself. And even more important: it’s Open Source! There is a hosted instance at invidio.us if you want to give it a try. But, wouldn’t it be cooler to host your own instance on your OpenShift cluster? Let’s do it! Continuer la lecture
Running Red Hat SSO outside of OpenShift
In an article named Red Hat Single Sign-On: Give it a try for no cost!, I explained how to deploy Red Hat SSO very easily in any OpenShift cluster. As pointed by a reader in a comment, as widespread OpenShift can be, not everyone has access to a running OpenShift cluster. So, here is how to run Red Hat SSO outside of OpenShift: using only plain Docker commands. Continuer la lecture
One-liner to decode a Kubernetes secret (base64 encoded)
Creating a Kubernetes secret from a value is easy: $ oc create secret generic my-secret --from-literal=secretValue=super-secret secret/my-secret created But getting back this value (from a Shell script, for instance) is not so easy since it is now base64 encoded: $ oc get secret my-secret -o yaml apiVersion: v1 kind: Secret metadata: name: my-secret namespace: qlkube type: Opaque data: secretValue: c3VwZXItc2VjcmV0 Hopefully, since the latest versions of Kubernetes, there is now a one-liner to extract the field and base64 decode it: Continuer la lecture