Applications

TL;DR I replaced Open WebUI with OpenClaw – a lighter, WebSocket-based AI assistant gateway that installs from npm, supports multiple chat channels (web, Telegram, Discord, WhatsApp), and deploys on k3s as a single Deployment with a custom Docker image. The primary model provider is Anthropic’s direct API (Claude Sonnet 4.5), with LiteLLM/Bedrock as a fallback. The biggest deployment lesson: OpenClaw binds to loopback by default, which makes it invisible to Kubernetes Services and health probes. The fix is --bind lan, which requires a gateway token for authentication. ...

TL;DR Cardboard is a TCG price tracker that monitors sealed product prices across 10 trading card games. It scrapes TCGPlayer and eBay using a three-tier strategy: pure API calls for bulk data, headless Selenium for product pages, and non-headless Selenium with a virtual display for sites that actively detect headless browsers. The scrapers run as Kubernetes Jobs on the same k3s cluster from Cluster Genesis. A Flask dashboard with Chart.js renders historical price data, profit/loss calculations, and portfolio tracking. All scraping is intentionally rate-limited to match normal human browsing patterns – the goal is polite data collection, not stress testing someone else’s infrastructure. ...

TL;DR The digital signage system was pulling weather from OpenWeatherMap, calendar events from Google Calendar, and device status from MQTT – three separate API keys, three separate failure modes. Home Assistant already had all of this data. I built an HA proxy service that exposes weather, forecasts, calendar events, temperature sensors, and arbitrary entity queries through a single Flask API backed by the Home Assistant REST API. Five new endpoints replaced three external dependencies. I also added API key authentication with role-based access control, wrote 37 tests, fixed MQTT addressing after a VLAN migration, and fought through 6 CI/CD fixes to get the pipeline deploying on self-hosted ARC runners. ...

TL;DR I built a complete swing trading research platform from an empty scaffold to 13,674 lines of Python in a single day. Five phases: data layer and backtesting, fundamentals and sentiment, portfolio construction, ML signals and Monte Carlo, then paper trading with a terminal dashboard. 199 tests across 48 test files. The platform fetches from Yahoo Finance, FRED, SEC EDGAR, and news APIs, runs technical and fundamental analysis, backtests strategies with walk-forward validation, and presents recommendations through a Rich terminal dashboard with human-in-the-loop approval. No cloud dependencies, no subscriptions, no vendor lock-in. ...

TL;DR Jellyfin dies mid-stream when a Kubernetes pod restarts because all transcode state is in-memory. I forked it, added a Redis-backed ITranscodeSessionStore, and wired in atomic lease-based pod takeover. The fork is at github.com/ZoltyMat/jellyfin-ha, and I also published a repo-level diff document at docs/FORK-DIFF.md showing exactly what changed versus upstream Jellyfin. Single-instance deployments need zero config changes because it falls back to a no-op store transparently. The Problem Jellyfin is great. It’s also built with the assumption that exactly one server instance is running at a time. Transcode state — which pods are running FFmpeg, what segments have been written, who owns a given play session — lives entirely in memory. When the process dies, that state is gone. ...

TL;DR Over the last six posts, I’ve documented converting Jellyfin from a single-process media server into a two-replica, PostgreSQL-backed, sticky-session-coordinated deployment on k3s. Five of six failover tests passed cleanly. The key result: zero-downtime failover — killing a pod doesn’t take down the service. Users on the surviving replica see no interruption; displaced users reconnect in seconds. Node maintenance no longer kills Jellyfin for the household. But this project isn’t finished, and some problems can’t be solved with this architecture. This final post is an honest inventory of what’s still broken, what was deferred, and what the path forward looks like. ...

TL;DR Phase 3 is where the rubber meets the road. We have PostgreSQL for persistent data (Day 4) and NFS for shared config. But Jellyfin still holds critical runtime state — sessions, users, devices, tasks — in 11 ConcurrentDictionary instances scattered across singleton managers. Two pods with independent memory spaces means two independent views of reality. This post covers the state externalization decision: what got moved to Redis, what got solved by sticky sessions, what got disabled entirely, and why pragmatism beat perfection for a homelab media server. ...

TL;DR Jellyfin stores everything in SQLite. Metadata, users, activity logs, authentication — all of it lives in .db files that lock under concurrent access. To run multiple replicas, we need a real network-accessible database. This post covers Phase 1 of the HA conversion: forking Jellyfin, designing a pluggable database provider interface, implementing it for PostgreSQL with Npgsql, generating EF Core migrations, writing integration tests with Testcontainers, and building a custom Docker image. ...

TL;DR Jellyfin is a fantastic open-source media server. It is also, architecturally, a single-process application that assumes it’s the only instance running. SQLite as the database. Eleven ConcurrentDictionary caches holding sessions, users, devices, and task queues in memory. A file-based config directory that gets written to at runtime. None of this survives a second pod. This is the first post in a seven-part series documenting how I converted Jellyfin into a highly available, multi-replica deployment on my home k3s cluster. The project spans two repositories, four phases, ~20 GitHub Issues executed by AI agents, and a live failover demo where I killed a pod and the service continued with zero downtime — users on the surviving replica never saw an interruption. ...

TL;DR I deployed a private, self-hosted ChatGPT alternative on the homelab k3s cluster. Open WebUI provides a polished chat interface. LiteLLM acts as a proxy that translates the OpenAI API into AWS Bedrock’s Converse API. Four models are available: Claude Sonnet 4, Claude Haiku 4.5, Amazon Nova Micro, and Amazon Nova Lite. Authentication is handled by the existing OAuth2 Proxy – no additional SSO configuration needed. The whole stack runs in three pods consuming under 500MB of RAM, and the only ongoing cost is per-request Bedrock pricing. No API keys from OpenAI or Anthropic required. ...