Systems and Infrastructure

Welcome to my website. I’m Dami Ola. I work across cloud infrastructure, automation, and operations, mostly in AWS environments.

A lot of my work is about building something and then keeping it running once it is live. I spend time on infrastructure as code, CI/CD workflows, Linux environments, monitoring, and the identity and networking pieces that connect everything together.

I write about what happens after deployment. Where systems break, how failures show up, and what changes once automation is introduced. I document the fixes, the mistakes, and the parts that were not obvious at the start.

This site is a record of that work. It is mostly labs and walkthroughs that reflect real environments, along with the troubleshooting and decisions behind them.

If you are interested in DevOps or cloud infrastructure, you should find something useful here.

How Linux Questions Reveal Your Systems Thinking in DevOps Interviews

DevOps interviews rarely include a round labeled “Linux”, but Linux is present in almost every technical discussion. It appears when containers fail to start, when a deployment hangs, when disk fills unexpectedly, when a service cannot be reached. Linux questions inside DevOps interviews are rarely about commands alone. They reveal whether you understand how systems behave underneath modern infrastructure. Below are common Linux-style questions that come up in DevOps interviews, and what they actually evaluate. ...

What Actually Happens Between docker build and a Running Server

The first time I ever built a Docker image, it worked. The container started, port mapped, and the app responded in the browser. But if I’m being honest, I couldn’t clearly explain what happened between docker build and seeing that response. I understood the commands, but I did not fully understand the flow. In this write-up, I will walkthrough a small application from source code to a running container on a remote server and explain what is happening at each stage. ...

Lowering Setup Cost With Containers

Docker changed what I consider worth setting up. Without containers, trying new software usually means committing to an environment: Pick an OS. Install dependencies. Open ports. Configure access. Hope you remember what you did the next time you come back. Even when the goal is just to try something, the setup feels heavier than the thing you’re actually interested in. The cost in time adds up, now you’re more hesitant to fire up the service or tool. ...

I Got Tired of Rebuilding Docker Test Environments, So I Terraform’d It

I’m rebuilding part of my AWS setup and figured this was a good time to write this down instead of relying on memory and vibes. Any time I need a clean Docker environment to test images or mess around without breaking anything important, I really don’t want to be clicking through the AWS console or babysitting a server. The problem is always the same. I need an Ubuntu box, Docker installed, basic access set up, and I need it quickly. Doing this manually means clicking through EC2, setting up security groups, opening ports, SSH’ing in, installing Docker, and then deciding what to do with the instance when I’m done. ...

Joining Rocky Linux 9 to Windows Server 2022 Active Directory (UTM)

I’ve built and documented Windows Active Directory labs before, you will find some on this website and some on my GitHub. Linux joining AD is conceptually simpler, but operationally more fragile. One wrong DNS setting, one wrong network mode, nothing works, and now I’m mad at my computer, trying to figure out what went wrong. This lab documents the correct mental model, and the exact steps I took to complete it. ...

Windows AD Lab on UTM: Join a Windows 10 Client to the Domain

In a previous post, I explained the steps to take to create a Windows Active Directory (AD) and get it ready for client computers to join. You can find the post here. Today, I will be walking through the process of joining a Windows 10 client to the AD and also some “fun” things we can do with the AD, and try to replicate some domain/enterprise-wide settings used in the real world. ...

Windows AD Lab on UTM: Build a DC, DNS, and DHCP

This lab walks through the steps I took to build a basic Active Directory (AD) lab environment using Windows Server 2022 as the Domain Controller (DC) and Windows 10 as the client. Everything was done inside UTM. In a later post, I will cover joining a Linux client to this Windows server. Setting up the virtual machines I downloaded the Windows Server 2022 and Windows 10 Enterprise ISO files from Microsoft Evaluation Center. I noticed Microsoft took the Windows 10 ISO off their website because they stopped supporting security updates for Windows 10, but I have uploaded it here. You should still be able to find the Windows 10 Server on the Microsoft Evaluation Centre. I used to run this lab on VirtualBox on my 2019 Intel MacBook Pro, but I spilled a glass of margaritas on that computer. VirtualBox does not work well on Apple Silicon, so I switched to UTM. Don’t drink around your computer guys! ...