Linux on Charlie Howlett

Managing My Homelab with Ansible

Tue, 18 Aug 2026 00:00:00 +0000

In previous posts, I described how I set up my repurposed laptop server and Raspberry Pi server rack. Together, they have grown into a useful little homelab.

The top-level topology is simple, but the deployed services and their configuration complicate things quickly.

It can be tricky to keep track of:

Mobile Dev Setup

Fri, 03 Jul 2026 00:00:00 +0000

I’ve always felt quite restless once I start working on a project. If I’m sitting in a park, on a train, or away from my desk with an idea in my head, I often want to make a quick change or keep a thread of work moving. But without my laptop I’ve always had to settle for doing something else. Still, I have always been curious about what options were available so years ago I looked into Termux, an app that provides a terminal on your phone. I wanted to try coding on the go, but writing productive code from such a small screen and keyboard felt impractical. However, when AI agents came along the idea started to seem much more realistic so I decide to try again.

Monitoring My Homelab with Grafana

Wed, 17 Jun 2026 00:00:00 +0000

Once I had several processes running continuously in my homelab, I needed a single place to inspect what they were doing. Connecting to a machine via SSH and reading logs directly is useful, but hardly convenient, so I set up an observability platform. I use Grafana for querying and visualising logs, Loki for storing and querying logs, and Grafana Alloy for collecting and forwarding logs. The components run as Docker containers on a Raspberry Pi with an attached SSD for persistent storage.

Git Auto Sync

Sun, 14 Jun 2026 00:00:00 +0000

After setting up my Raspberry Pi home lab, I deployed a small project onto one of the Pis and immediately wanted a cleaner method for continuous deployment. The app lived in a Git repository, and I wanted the running copy on the Pi to update automatically whenever the repo changed.

The obvious approach would have been a webhook: GitHub sends a request, a local service receives it, and the Pi pulls the latest code. I decided against that for security reasons. I did not want to expose a service on my home network just so GitHub could tell it that a commit had landed, and I did not want to build a tunnel or webhook receiver for something that could be solved more simply.

Monitoring Devices on My Home Network

Sat, 13 Jun 2026 00:00:00 +0000

My router gives me a basic view of the devices currently connected to my network, but it does not expose historical information. I started this project to fill that gap: a small Raspberry Pi service that scans the LAN, records which devices it sees, and shows that data in a dashboard.

Implementation

The service periodically runs arp-scan to discover devices on the local network, then stores the results in a database with both the current device state and a history of online/offline events. That split lets the system track when a device first appeared, when it was last seen, and how its presence changed across a day or week.

Building a Raspberry Pi Server Rack

Fri, 12 Jun 2026 00:00:00 +0000

I had three old Raspberry Pis and an SSD sitting unused in a cupboard, so I decided to turn them into a small cluster of home servers. I wanted the finished setup to be compact and tidy enough to live on a little shelf in my television stand, rather than becoming another loose collection of boards, cables, and power adapters tucked away in some cupboard.

For the chassis, I joined two 12-inch server rack trays using a pair of small rack-mounting posts. This was cheaper than buying a premade desktop rack and gave me a reusable foundation: if I later expand the cluster or move it into a larger rack, the trays and mounting hardware can become part of the new setup.

Repurposing a Laptop as a Home Server

Fri, 22 May 2026 00:00:00 +0000

I was recently given an old laptop that had been retired by my company. Despite no longer being needed for work, it still had quite capable hardware, so I decided to repurpose it as a compact, general-purpose home server rather than let it go unused.

Because the server will remain plugged in, I removed the battery to reduce unnecessary heat and avoid leaving an ageing battery permanently charging. I also removed the display, which improved airflow, made the machine easier to fit into tight spaces, and left the power button accessible without needing to open and close a lid. I saved the screen so it can be reused in a future project.

Automating Lights with a Raspberry Pi

Thu, 02 Sep 2021 00:00:00 +0000

Pi Lights was a fairly simple idea and my first exploration into DIY home automation: measure the ambient light level throughout the day using a Raspberry Pi, then switch Wi-Fi lights on or off automatically.

Implementation

The system polls several light-dependent resistors and averages their readings before deciding whether to switch the lights. Using multiple sensors and rate-limiting changes made the automation less sensitive to brief shadows or sudden changes in brightness. A dedicated light-sensing Raspberry Pi HAT would have been more accurate, but I wanted to see if I could build a first pass using components I already had lying around. I ran the software as a Linux service so it would start automatically and continue working in the background without needing any attention.

Raspberry Pi Digital Lock

Fri, 02 Nov 2018 00:00:00 +0000

This first-year group project started with a simple brief: build a keypad-controlled digital lock using a Raspberry Pi. It was a small project, but a very rewarding one, and it introduced me to some great people. Ultimately, our project was chosen by the lecturer to be demonstrated at subsequent university open days.

The main constraint was that we were not allowed to rely on interrupt-driven input for the membrane keypad. Instead, we had to detect key presses by polling the Pi’s pins and working through the keypad matrix ourselves. On top of the basic four-digit passcode entry, we added status LEDs for correct and incorrect codes, a short delay after failed attempts to make brute forcing less practical, and a text-based interface for changing settings after the user had gained access. We also wrote software to attack our own system by generating electrical signals that mimicked key presses.