du.nkel.dev

Local-only Marstek Venus E Battery Integration with Home Assistant

Sun, 11 Jan 2026 00:00:00 +0000

Integrating a cheap (~1050€) 5kWh AC-coupled battery into an existing 30kWp PV system. The goal: Zero-cloud dependency, full local control via Modbus TCP, and a 'Zero Export' regulation loop using Home Assistant. This post covers the physical installation using a standard TV mount, RS485 wiring, and the complete software logic.

Lokale Einbindung und Steuerung vom Marstek Venus E Batteriespeicher mit Home Assistant

Sun, 11 Jan 2026 00:00:00 +0000

In diesem Beitrag beschreibe ich die Integration eines günstigen (~1050€) 5kWh AC-Speichers in eine bestehende 30kWp PV-Anlage mit Open-Source tools. Das Ziel: Null Cloud-Abhängigkeit und volle lokale Kontrolle mittels Modbus TCP und Nulleinspeisungs-Automatik in Home Assistant. Ich zeige die physische Installation mit einer Standard-TV-Wandhalterung, die RS485-Verkabelung und teile die komplette Software-Logik.

Automating rootless Docker host updates with Ansible

Sat, 15 Nov 2025 00:00:00 +0000

Running apt upgrade on hosts with rootless Docker services can break them. A version mismatch occurs between the running user daemon and the newly upgraded system binaries, causing containers to fail on restart. This post provides an ansible playbook that detects critical package changes and automatically restarts only the necessary rootless user daemons, preventing downtime and manual intervention.

Keycloak SSO with docker compose and nginx

Sun, 11 Feb 2024 00:00:00 +0000

I always hesitated to deploy an extra tool for user management and SSO, but the current state of the web makes it very difficult to keep up with security, CVEs etc. Why not trust one of the longest standing solutions for identity and access management? Keycloak is open source, interoperable with major SSO protocols (OpenID Connect (OIDC), OAuth 2.0, SAML), and robust. The setup with docker compose is not complicated, but it was not straight forward either. This is why I provide a summary of the process below.

Mastodon with docker rootless, compose, and nginx reverse proxy

Tue, 12 Dec 2023 00:00:00 +0000

Everyone talks about docker rootless, e.g. for security reasons, but no one actually seems to do it. Very little information is available. Migrations from rootfull systems? File permissions? Reverse-proxy setup? Here I go through the steps to run Mastodon

IPSEC between OPNsense and pfSense

Sat, 12 Nov 2022 00:00:00 +0000

A site-to-site connection between pfSense/OPNsense with IPSEC is straight-forward. This post explains some of the peculiarities needed to establish a connection, if one side is behind a Carrier-grade NAT or in an internal subnet. This can happen, for example, with an upstream WAN uplink that uses a dynamic IP address. I also show how to handle routing with multiple subnets on one end, using Classless Inter-Domain Routing (CIDR). The sections are largely independent, choose what's interesting to you.

Proxmox root migration (a report)

Thu, 04 Aug 2022 00:00:00 +0000

Migration is a tedious process because it depends on a number of custom setup parameters. Understandably, the Proxmox docs provide only basic information on how to migrate the hypervisor itself.

Flashing the Supermicro variant of SAS9201-16e (SAS2116)

Sun, 05 Dec 2021 00:00:00 +0000

Flashing SAS Cards feels like a trip to the 90s, with all the peculiarities included. This particular LSI SAS9201-16e card left me puzzled, until I realized it is the Supermicro variant that needs special handling. Let's see if I can pull together the important pieces, so that those who come after me don't need to give up on their cards.

Proxmox Hypervisor Monitoring with Telegraf and InfluxDB

Wed, 05 May 2021 00:00:00 +0000

This is a description of the process to install Telegraf on proxmox to collect sensor reading, smart data and metrics in InfluxDB 2.0.

Building SnapOS Image for Raspberry Pi Zero W with buildroot in WSL2

Sat, 10 Apr 2021 00:00:00 +0000

This is a description of the process to create `sdcard.img` for the Raspberry Pi Zero W with HiFiBerry DAC Hat in Windows Subsystem for Linux (WSL2).

Running docker inside an unprivileged LXC container on Proxmox

Thu, 25 Mar 2021 00:00:00 +0000

This is a brief description of the setup process for running docker in unprivileged LXC containers on proxmox. There are two primary sources, one is a post on Reddit and a more general discussion on linuxcontainers.org.