Notes

Rising Infrastructure Quality with YAML & JSON Schemas If you work in operations, DevOps, or platform engineering, you’re probably drowning in YAML files. Kubernetes manifests, Ansible playbooks, GitLab CI configurations, Helm charts—the list goes on. These YAML files control everything from cluster management and configuration to CI/CD pipelines and application deployments. But here’s the problem: YAML is notoriously forgiving. A typo, a missing field, or an incorrect indentation might not show up until you try to apply that configuration—and by then, it’s often too late. This is where JSON schemas come in, even though you’re working with YAML. ...

Introduction: When All Else Fails, Layer by Layer This week, I found myself knee-deep in troubleshooting Grafana Labs telemetry containers that refused to start properly in an OpenShift cluster (loki, mimir, prometheus, tempo, otel collector, spring boot services, etc.). The workloads looked good, the containers were running, but the telemetry data simply wouldn’t flow. Sound familiar? After hours of fruitless searching and even getting blocked by AI assistance (yes, even Claude couldn’t crack it), I realized I was in need of applying long learned principles. That’s when I decided to document the mental framework I developed over years of debugging network issues. ...

Introduction In Kubernetes clusters, pods rely on DNS resolution to communicate with other services and external resources. By default, pods use a DNS system within the cluster that operates with private addresses and the domain cluster.local. The DNS server responsible for this resolution is CoreDNS. Many applications are configured by default for standard Kubernetes setups, which can cause DNS resolution issues when deployed in OpenShift environments. Understanding how CoreDNS works and how to properly configure applications for OpenShift is crucial for ensuring reliable service discovery and communication. ...

Python virtual environments behind the scenes If you’ve been working with Python for a while, you’ve probably heard about virtual environments. Maybe you’ve even used them without fully understanding what’s happening behind the scenes. In this comprehensive guide, we’ll explore everything you need to know about Python virtual environments—from the basic concepts to the underlying mechanisms that make them work. What is a Python Virtual Environment? A Python virtual environment is an isolated Python installation that allows you to install packages and dependencies for a specific project without affecting your system’s global Python installation or other projects. Think of it as a separate, self-contained workspace for each of your Python projects. ...

Exploring Kargo.io as a GitOps deployment platform - from its impressive ArgoCD integration to the challenges that keep it from being enterprise-ready. A practical guide for platform engineers considering their next deployment tool.

Learn about CIDR notation, IP addressing, and subnetting in modern computer networking. This comprehensive guide covers the basics, benefits, and practical examples of Classless Inter-Domain Routing.

Why I’m publishing my personal notes After more than 10 years in tech, I’ve learned a considerable amount of what I know from publicly available resources — books, notes, documentation, and community projects. This platform is my way of giving back. When I encounter interesting problems or solutions in my daily work, I’ll write about them here. I believe the best way to learn is to teach, so I’ll explain the problems, solutions, and their benefits. ...