Kubernetes15 min read
Passing the CKA exam after years of Kubernetes
How I prepared for and passed the Certified Kubernetes Administrator exam, and what I'd do differently knowing what I know now.
Blog
Kubernetes12 min read
Choosing a Kubernetes dashboard for your team
Headlamp, OpenShift Console, or the deprecated Kubernetes Dashboard. Here's how they compare and which one fits your team.
OpenShift9 min read
OpenShift Switched to OVN-Kubernetes. Here's What Changed.
OpenShift switched from OpenShift SDN to OVN-Kubernetes. Here's what changed and what you need to know.
Helm13 min read
Library Charts and the Death of Copy-Paste Templates
You have 5 charts that all need the same labels, annotations, and helper functions. Copy-paste isn't the answer.
OpenShift9 min read
How Your Developers Log Into OpenShift (And Why kubeadmin Isn't Enough)
How do your developers log into the OpenShift console? If the answer is kubeadmin, we need to talk.
OpenShift8 min read
Installing Operators on OpenShift: Skip the Helm Chart, Use OperatorHub
You need to install a database operator. In vanilla Kubernetes, you'd use Helm. In OpenShift, there's a better way.
Helm11 min read
Helm Hooks: Controlling When Things Happen
Your database migration runs before the app starts. How do you guarantee that in Helm?
OpenShift8 min read
Where Do Your Images Live? OpenShift's Internal Registry and ImageStreams
Your images don't live in Docker Hub anymore. Where do they go? Inside the cluster, in an internal registry managed by OpenShift.
Helm10 min read
Stop Hosting Your Helm Charts on GitHub Releases
Your charts shouldn't live in a GitHub repo's releases page. OCI registries solve chart distribution properly.
OpenShift7 min read
DeploymentConfig Is Dead. Long Live Deployment.
DeploymentConfig looks like Deployment but it's not. And you should probably stop using it.
Kubernetes7 min read
Namespace Is the New Cluster Boundary
Namespaces aren't just for organizing resources. They're your first line of defense against a single team eating the whole cluster.
OpenShift9 min read
Changing Kernel Parameters on OpenShift Nodes: The MachineConfig Way
You need to change a kernel parameter on all your worker nodes. How? OpenShift's MachineConfig is the answer.
Kubernetes9 min read
Server-Side Apply: Who Wins When Three People Apply the Same Resource?
Three people, three kubectl apply, one resource. Server-Side Apply finally gives you a real answer to who wins.
OpenShift8 min read
You Didn't Install Prometheus. OpenShift Did.
Where are your metrics? You didn't install Prometheus. OpenShift did it for you. Here's how to use the built-in monitoring stack.
Kubernetes8 min read
Debugging Crashed Containers with kubectl debug
You can't exec into a crashed container. It's crashed. Here's how kubectl debug gets you out of that hole.
Helm14 min read
Building Helm Charts the Right Way
Every team eventually builds their own Helm chart. Here's how to do it right from the start.
Kubernetes8 min
Endpoints Are Dead. Long Live EndpointSlices.
kubectl get endpoints shows you one thing. EndpointSlices show you another. Here's why the old model broke and what replaced it.
OpenShift10 min read
Your Pod Won't Start: Decoding OpenShift's Security Context Constraints
Your pod won't start. The error says: unable to validate against any security context constraint. Here's what that means and how to fix it.
OpenShift9 min read
OpenShift Routes vs Kubernetes Ingress: An Honest Comparison
OpenShift has Routes. Kubernetes has Ingress. Which one should you use? The answer depends on your cluster.
Kubernetes10 min
From 10 to 10,000 Requests: HPA v2 and the Art of Actually Scaling
Your app handles 10 requests per second. Traffic doubles. What happens? If you're only using CPU metrics, the answer is probably wrong.
OpenShift8 min read
Day One with OpenShift: oc is Not kubectl (But Also Kind of Is)
I joined a new project and the onboarding doc said: install oc. Here's what I learned switching from kubectl to OpenShift's CLI.
Kubernetes9 min
Kubernetes 1.24 Killed Two Things: Docker and Your Excuse for Bad Pod Security
Everyone talked about dockershim removal. Nobody talked about Pod Security Admission replacing PSP. That's the bigger deal.
Kubernetes8 min read
How Services Find Pods (And Why You Should Care)
Pods die. Their IPs change. How do you find them? Services, and the networking model underneath.
Linux6 min read
Vim survival guide for Linux admins
The minimum vim knowledge you need to survive on a Linux server. Editing config files without wanting to throw your keyboard.
Linux6 min read
Understanding the Linux filesystem hierarchy
Where things live on a Linux system and why. A practical guide to the directory layout.
Linux7 min read
Understanding PAM authentication
How Linux authentication works under the hood. PAM modules, configuration files, and common customizations.
Kubernetes7 min
A Node Dies Mid-Rollout: PodDisruptionBudgets Save Your Uptime
You're doing a rolling update. Halfway through, a node dies. How many pods stay running? PDBs decide.
Linux6 min read
Understanding Linux swap space
What swap is, when Linux uses it, how much you need, and how to configure swap files and partitions.
Kubernetes8 min
Your Pods Are Exposed: Locking Down Kubernetes Networking
Every pod in your cluster can talk to every other pod by default. That's terrifying. Here's how NetworkPolicies fix it.
Linux7 min read
Tuning Linux kernel parameters with sysctl
Runtime kernel tuning with sysctl. Network performance, memory management, and security hardening parameters.
Backend10 min read
What I learned building a banking backend
A banking app needs more than CRUD. It needs authentication that actually works, transactions that don't lose money, and an architecture that doesn't collapse when you add features.
Linux6 min read
tmux: terminal multiplexing made simple
Using tmux to manage terminal sessions. Panes, windows, and why your SSH sessions should survive disconnects.
Backend9 min read
Why I tried Spring Boot (and what confused me)
Everything in Node.js is a callback. In Spring Boot, nothing is. The mental model is completely different, and switching was harder than I expected.
Kubernetes8 min read
CronJob Finally Graduated to batch/v1 in Kubernetes 1.21
CronJobs are GA in Kubernetes 1.21. Here's what that means, and how Jobs and CronJobs actually work.
Linux5 min read
Time synchronization with NTP
Keeping Linux clocks accurate with chrony and systemd-timesyncd. Why time matters and how to configure it.
Linux9 min read
SSH hardening: securing remote access
Practical steps to lock down SSH on your Linux server. Key-based auth, disabling root login, and fail2ban basics.
Backend8 min read
Building a real app with Express.js and a team
The JWT tutorial worked. Now I needed to build something real, with other people. Here's what happens when theory meets a team project.
Backend7 min read
From frontend JavaScript to my first backend API
I'd been writing frontend JavaScript for a while, but had no idea what happened on the other side of my API calls. Here's how I went from fetch() to actually building the server.
Kubernetes9 min read
DaemonSets and StatefulSets: When Deployments Aren't Enough
You need exactly one pod on every node. Deployment can't do that. Here's what can.
Linux7 min read
Setting up Apache on Ubuntu
Installing and configuring Apache. Virtual hosts, .htaccess, modules, and the settings you'll want to change.
Linux7 min read
Securing Linux with fail2ban
Setting up fail2ban to protect SSH and web services. Writing custom filters and understanding ban actions.
Kubernetes11 min read
Your App Pods Can Talk to the Kubernetes API (And You Probably Didn't Know)
By default, every pod in your cluster has API access. RBAC is how you lock that down.
Linux7 min read
rsync: the Swiss Army knife of file sync
Copying files efficiently with rsync. Local and remote sync, incremental backups, and the flags you'll actually use.
Kubernetes8 min read
Stop Putting Environment Variables Directly in Your Deployment Manifests
Hardcoded env vars in Deployment specs are a maintenance nightmare. ConfigMaps and Secrets exist for a reason.
Linux6 min read
Package management with apt
Installing, removing, and managing software packages on Ubuntu and Debian. Repositories, pins, and common gotchas.
Kubernetes10 min read
Persistent Volumes: Keeping Data Alive When Pods Die
Your pod restarts and all its data is gone. Persistent Volumes fix that, but the setup is more nuanced than the docs suggest.
Kubernetes10 min read
Your Pod Keeps Getting OOMKilled: Resource Requests, Limits, and QoS Classes
Diagnosing OOMKilled pods, setting sensible resource requests and limits, and understanding the QoS class framework.
Helm12 min read
Helm 2, Tiller, and the Messy Beginning of Kubernetes Package Management
In 2019, deploying to Kubernetes meant writing YAML. Lots of YAML. Helm 2 tried to fix that, but came with its own baggage.
Linux10 min read
Bash scripting for beginners
Writing your first bash scripts. Variables, conditionals, loops, and the patterns you'll actually use on a server.
Linux8 min read
Nginx basics: serving static content
Setting up Nginx as a static file server and reverse proxy. Configuration basics, virtual hosts, and performance tuning.
Linux7 min read
NFS: sharing files across Linux machines
Setting up NFS shares between Linux servers. Server configuration, client mounting, and performance tuning.
Linux7 min read
Managing users and groups on Linux
Adding, modifying, and removing users. How groups work and why /etc/passwd still matters.
Kubernetes9 min read
Kubernetes Probes and Init Containers: Knowing When Your Pod Is Actually Ready
A pod is running. But is it ready? Understanding liveness, readiness, and startup probes, plus how init containers set the stage.
Linux6 min read
Managing SSL certificates with Let's Encrypt
Getting free SSL certificates with Let's Encrypt and certbot. Installation, renewal, and troubleshooting.
Linux8 min read
Managing services with systemd
Starting, stopping, and debugging services with systemctl. Writing basic unit files and understanding targets.
Linux7 min read
Log management with journalctl and rsyslog
Reading systemd logs with journalctl, configuring rsyslog for remote logging, and managing log rotation.
Linux7 min read
Linux process management: ps, top, and beyond
Finding runaway processes, understanding process states, and managing background jobs.
Linux8 min read
Linux networking basics: ip, ss, and troubleshooting
Checking interfaces, routing, and connections with modern Linux networking tools. Replacing ifconfig and netstat.
Linux7 min read
Linux memory management: free, vmstat, and /proc
Understanding how Linux uses memory. Reading free correctly, using vmstat, and what /proc/meminfo actually tells you.
Linux8 min read
Linux file permissions explained
How Linux file permissions work, what chmod numbers actually mean, and when to use chown vs chgrp.
Linux12 min read
iptables essentials: a practical guide to Linux firewalling
A hands-on guide to iptables. Covers chains, tables, rule syntax, and real examples for securing a Linux server.
Linux10 min read
grep, sed, and awk: the Linux text processing trio
Finding, replacing, and transforming text from the command line. Practical examples for each tool.
Linux9 min read
Disk management with LVM
Logical Volume Management: resizing partitions without reboots, adding disks on the fly, and snapshots.
Linux7 min read
Cron jobs: scheduling tasks on Linux
How cron works, writing crontab entries, common pitfalls, and when to use alternatives.