Articles by Thomas Jungbauer

In standard OpenShift Container Platform (OCP) installations, the cluster networking operator relies on default scripts to configure the external bridge, br-ex. While these defaults work for simple setups, production environments frequently demand robust and redundant setups, such as LACP bonding or active-backup configurations that the default scripts cannot guess.

In this article, we explore advanced configurations for the br-ex bridge on OpenShift. We will configure a worker node with a high-availability active-backup bond, attach it to an OVS bridge (br-ex), and ensure the node maintains connectivity.

OpenShift GitOps based on Argo CD is a powerful tool to manage the infrastructure and applications on an OpenShift cluster. Initially, there were two ways of deployment: centralized and decentralized (or distributed). Both methods had their own advantages and disadvantages. The choice was mainly between scalability and centralization. With OpenShift GitOps v1.19, the Argo CD Agent was finally generally available. This agent tries to solve this problem by bringing the best of both worlds together. In this quite long article, I will show you how to install and configure the Argo CD Agent with OpenShift GitOps using hub and spoke architecture.

It’s time to dig into OpenShift Virtualization. You read that right, OpenShift Virtualization, based on kubevirt allows you to run Virtual Machines on top of OpenShift, next to Pods. If you come from a pure Kubernetes background, OpenShift Virtualization can feel like stumbling into a different dimension. In the world of Pods, we rarely care about Layer 2, MAC addresses, or VLANs. The SDN (Software Defined Network) handles the magic and we are happy.

But Virtual Machines are different…​.

This page provides an interactive visualization of all available ArgoCD applications from the openshift-clusterconfig-gitops repository.

The repository demonstrates the usage of OpenShift GitOps with (mainly) Helm Charts that I use for my own clusters. As easy Secret Management I have Sealed Secrets. It focuses on main cluster configuration using a GitOps approach. Some of the charts or configurations are discussied in my blog posts. Please refer to the different GitOps blog posts for more details and to understand why it is done this way.

The GitOps Catalog page provides an interactive visualization of all available ArgoCD applications from the openshift-clusterconfig-gitops repository. Check out the page GitOps Catalog for more details.

Recently, I encountered a problem deploying a Hosted Control Plane (HCP) at a customer site. The installation started successfully—etcd came up fine—but then it just stopped. The virtual machines were created, but they never joined the cluster. No OVN or Multus pods ever started. The only meaningful message in the cluster-version-operator pod logs was:

This page shows the latest updates to the stderr.at Helm Charts Repository. The charts are designed for OpenShift and Kubernetes deployments, with a focus on GitOps workflows using Argo CD.

In the previous articles, we deployed a distributed tracing infrastructure with TempoStack and OpenTelemetry Collector. We also deployed a Grafana instance to visualize the traces. The configuration was done in a way that allows everybody to read the traces. Every system:authenticated user is able to read ALL traces. This is usually not what you want. You want to limit trace access to only the appropriate namespace.

In this article, we’ll limit the read access to traces. The users of the team-a namespace will only be able to see their own traces.

While we have been using the integrated tracing UI in OpenShift, it is time to summon Grafana. Grafana is a visualization powerhouse that allows teams to build custom dashboards, correlate traces with logs and metrics, and gain deep insights into their applications. In this article, we’ll deploy a dedicated Grafana instance for team-a in their namespace, configure a Tempo datasource, and create a dashboard to explore distributed traces.

While we have created our distributed tracing infrastructure, we created two tenants as an example. In this article, I will show you how to add a new tenant and which changes must be made in the TempoStack and the OpenTelemetry Collector.

This article was mainly created as a quick reference guide to see which changes must be made when adding new tenants.