Posts on SETE

PV Erweiterung 1

Mon, 06 Apr 2026 00:00:00 +0000

Disclaimer:
Ich arbeitederzeit bei Fronius.
Es sind keine Komponenten von der Firma Fronius zur Verfügung gestellt worden. Alle Komponenten wurden selbst bezahlt. Ich bekommen keinerlei Vergütung dafür über diesen Umbau zu schreiben. Bitte dies auch nicht als Werbung zu verstehen, sondern als reinen Erfahrungsbericht. Dies ist keine Anleitung oder Beratung. Die technischen Vorschriften können sich ändern je nach Voraussetzungen.

Ziele Link zu Überschrift

Umbau der Anlage von Mikroinverter auf Stringinverter.
3Phasen Drehfeld im Notstrombetrieb.
Vorbereitung auf Batteriespeicher und Notstromumschaltung.

Ausgangslage Link zu Überschrift

Jahresgesamtverbrauch ~2500 kWh
Netzzugang 4 KW
Einspeisebegrenzung 4 kW

Warmwasseraufbereitung Link zu Überschrift

Boiler zur Warmwasseraufbereitung mit Luftwärmepumpe: warmwasser-waermepumpe-wpa-450
Nominale Stromaufnahme ~1 KW (Wärmepumpe)

Linux Mint Unattended Installation

Mon, 22 Dec 2025 00:00:00 +0000

Originally published on LinkedIn on 2025-12-22.

An Article about Rubenshof - Linux Mint Unattended Installer

Every year we set up some devices for our students at school. This year we had the situation of delayed deliveries, because a donation of notebooks took longer than expected. So we have to get faster with setting the devices up. I took this challenge and created a unattended Workstation setup for our school.

Cloud-Init What?

Sun, 23 Nov 2025 00:00:00 +0000

Originally published on LinkedIn on 2025-11-23.

It’s common for IT Administrators managing classical enterprise Virtual Machine (VM) infrastructure to overlook powerful, existing tools for automation and scale-out. While the benefits of cloud-native deployment patterns—like disposable, self-configuring infrastructure—are well-understood, many don’t realize that similar, workflow-based efficiency is achievable for their on-premises VMs. The necessary technology has been available for years.

The most effective solution for modernizing VM deployment involves adopting a two staged approach:

0 Vulnerabilities - Think twice about it

Wed, 22 Oct 2025 00:00:00 +0000

Originally published on LinkedIn on 2025-10-22.

Vulnerability scans can be tricky and there are different strategies. It starts already at the datasets provided by the different OS and how they are implemented from the scan tools. For example Alpine. A lot Engineers think it is secure because 0 vulnerabilities shown at scans with tools like trivy.

But there is security.alpinelinux.org and information about potential CVEs within Alpine packages.

And Alpine provides also information about CVEs which are already fixed within the secdb.alpinelinux.org service.

Opennebula evaluation for Homelab

Sat, 18 Oct 2025 00:00:00 +0000

Originally published on LinkedIn on 2025-10-18.

Since I didn’t use Opennebula for a while but had good experience with it at the past, I decided to check what is new within this project. Therefore I instantiated a miniONE instance in the proxmox Homelab.

Deploy miniONE on the virtualized node: Hotwto Deploy
Validate the installation: Validation
Run Kubernetes on miniONE: K8S rollout

Deployment Link zu Überschrift

miniONE installation on ubuntu 24.04

Monitoring a TV Headend

Wed, 22 Jan 2025 00:00:00 +0000

Originally published on LinkedIn on 2025-01-22.

In my experience working with cloud environments, I’ve extensively used Prometheus, Grafana, and Alertmanager for monitoring. However, when dealing with TV Headends, I’ve encountered a common challenge: the lack of Prometheus endpoints for directly scraping metrics.

To overcome this, we can leverage the widely available SNMP (Simple Network Management Protocol)

Integrating SNMP with Prometheus Link zu Überschrift

SNMP Exporter Link zu Überschrift

Prometheus offers an official open-source SNMP exporter, making it easy to collect SNMP data.
To effectively gather metrics from less common hardware, utilize MIB (Management Information Base) files provided by the manufacturer. For example, Astro Strobel BC4 headends offer a downloadable ZIP file containing relevant MIBs from their controller’s web interface.

This approach allows for seamless integration of traditional SNMP data with the powerful monitoring capabilities of the Prometheus ecosystem.

Virtualized School IT Lab

Sun, 19 Jan 2025 00:00:00 +0000

Originally published on LinkedIn on 2025-01-19.

This Lab environment was created for a showcase at a local school. The school, a small community-driven institution based on Montessori principles, serves approximately 70 children and teachers. Open Source and Free and Open-Source Software (FOSS) are valued by some of the teaching staff, and they requested assistance with certain aspects of the school’s infrastructure. Considering this preference, a cloud solution was deemed unsuitable.

Important Note: This is solely a LAB environment and should not be used for production purposes. It lacks critical security measures, including data protection, backups, encryption, network isolation, and other essential elements required for production environments. This lab is intended for demonstration and educational purposes only.

PV Anlage

Fri, 02 Aug 2024 00:00:00 +0000

Ziele Link zu Überschrift

Die Errichtung einer PV-Anlage, um den Energiebedarf der Warmwasseraufbereitung abzudecken. Inselbetrieb ist nicht vorgesehen.

Ausgangslage: Link zu Überschrift

Boiler zur Warmwasseraufbereitung: warmwasser-waermepumpe-wpa-450

Nominale Stromaufnahme ~1 KW (Wärmepumpe)

Netzzugang 4 KW

Durchführung Link zu Überschrift

Planung PV: Link zu Überschrift

Einbindung in Homeassistant
3,5 KWp Generatorleistung
Bestehendes Open-Source-Projekt, um Daten des Wechselrichters auszulesen und in Homeassistant zu integrieren
Einbinden der Zählerdaten in Homeassistant
Mikrowechselrichter, um Gleichspannungen in Strings gering zu halten

Komponenten: Link zu Überschrift

Homeassistant in Docker auf bestehendem Linux-Nextcloud-Server
MQTT-Server in Homeassistant
Daten auf NFS-Storages
Hoymiles Wechselrichter HMS-1600 2x
OpenDTU DIAMEX DX-DTU-MAX, Gateway für Hoymiles 1x
Mitterbauer AMIS-Leser 1x
JA Solar Solarmodul 435W Glas-Glas Full Black Bifacial 8x

Einmeldung NetzOOE: Link zu Überschrift

Da diese Anlage die Generatorleistung von 800W übersteigt und somit kein Balkonkraftwerk ist, habe ich die Anlage bei der NetzOOE eingemeldet. Dies kann von einem Elektrotechnik-Fachbetrieb, der Marktpartner bei der NetzOOE ist, eingemeldet werden. Wird der Netzzugang nicht überschritten, ist das eine relativ unkomplizierte Sache.

vault snap to S3 in kubernetes

Wed, 24 May 2023 00:00:00 +0000

Originally published on LinkedIn on 2023-05-24.

Hashicorp Vault Link zu Überschrift

In vault-enterprise there would be an integrated solution to upload backups to S3 compatible storages. In the Open Source version of Vault this feature is missing, so I had to create some solution for this.

Most times I use the integrated raft storage inside the vault cluster in kubernetes. Data of this StatefulSet is stored in PersistentVolumeClaims. (Where I also patched the default persistentVolumeReclaimPolicy to Retain the deletion of the StatefulSet, but that’s a different story)

GitOPS with ArgoCD

Fri, 12 May 2023 00:00:00 +0000

Originally published on LinkedIn on 2023-05-12.

Intro Link zu Überschrift

In 2007, when I started to work in tech, IT administrators relied often on shell scripts to automate their workflows. Virtualisation was not that popular and tools like PXE boot and bootstrap files where used to automate the installation of operating systems on multiple servers simultaneously. The network layer was very often operated without automation at all. Later, KVM was also gaining popularity, enabling administrators to create and manage virtual machines. As infrastructure became more complex, configuration management tools like Chef and Ansible became popular, allowing administrators to define infrastructure as code and apply configuration changes across multiple servers quickly and easily.

What are Terraform remote states?

Mon, 14 Feb 2022 00:00:00 +0000

Originally published on LinkedIn on 2022-02-14.

These days I learn to build a infrastructure in GCP. The past years I already worked with terraform and so I had already some experience with it. But I didn’t use terraform_remote_state as data source in the past.

A friend showed me how to use it, and it completely changed my way of writing terraform plans. Also the structure of my plans changed with this knowledge.

Service Ownership

Tue, 10 Aug 2021 00:00:00 +0000

Originally published on LinkedIn on 2021-08-10.

Over the last years I had the pleasure to take care at serveral internal IT tools as an engineer beside production IT. At the beginning it was just about set up a servers, give people access and keep it running (somehow). I often had to focus at multiple things at once. And it was okay. But years later, the company grew. Someone had to take ownership on tools which are used by everyone inside the company. I got asked to do this for a dedicated tool in internal IT and want to share my experiences a bit.

Use Build pipelines

Wed, 27 May 2020 00:00:00 +0000

Originally published on LinkedIn on 2020-05-27.

These days I was on vacation, and I’m preparing for my new job which I will start soon. A friend of mine asked for a bit of help with their mapserver RPM packages, because they needed a special combination of mapserver7.4.4 , php7.4, postgresql12 on CentOS7 and CentOS8.

Packer, Terraform, KVM Ansible solution: Link zu Überschrift

As I worked with some hashicorp products in the past I tried to create something local on my workstation on top of KVM together with packer, terraform-cli, terraform-libvirt and ansible. Nice to play around and get in touch with mapserver and compiling it. But this is way to complicated.

Use the power of automation

Fri, 01 May 2020 00:00:00 +0000

Originally published on LinkedIn on 2020-05-01.

I really like to automate things. So I also automate the creation and provision of base images for a datacenter environment.

There are some tools which solve this. In my case I prefer packer.io.

Why? Because it is opensource, supports a lot of different technologies, runs on different platforms and so on and so on. And it is simple and lightweight.

So with packer you can, build and provision images in cloud environments but also local with kvm, virtualbox or even hyper-v.

Get Fibre Channel HBA adapter metrics

Mon, 30 Mar 2020 00:00:00 +0000

Originally published on LinkedIn on 2020-03-30.

Since I deal with Fibre Channel, I have to deal with new tools as well. Today for example we had some issues on a Linux Server with Fibre Channel HBA setup. In fiber optic network you are looking for Rx/Tx power metrics, which I also get from the SAN switches. But to detect issues it’s good to see the RX/TX power also from the host side. The Linux support inside the company told me, that they can’t find metrics inside the system. So I tried to get some more knowledge about that topic.

Powershell + Gitlab

Sun, 19 Jan 2020 00:00:00 +0000

Originally published on LinkedIn on 2020-01-19.

In my last article I wrote about Powershell DevOps pipeline and that I would like to use gitlab-ce for that project. So today I combined some things that I’m interessted in, at my homelab. Lets spawn gitlab-ce with podman in a Centos 8.1 VM.

[administrator@podnode01 ~]$ sudo podman run --detach --hostname gitlab.test.vm --env GITLAB_OMNIBUS_CONFIG="external_url 'http://gitlab.test.vm/'"   --publish 443:443 --publish 80:80 --publish 222:22 --name gitlab gitlab/gitlab-ce:latest

Here we go. I create a git project on my local machine and pushed the repository to the gitlab-ce instance.

Powershell for me as PSDummy

Mon, 06 Jan 2020 00:00:00 +0000

Originally published on LinkedIn on 2020-01-06.

Hi together, as some of you know I took a new challenge last year and now I work for a big Healthcare Company in the IT department. Over the last years I got a lot of experience how to use automation tools in a homogeneous Linux infrastructure. In my new job things are different.

In the past I never thought to use Powershell, because there are tons of really good tools on Linux to configure and deploy stuff. Like Terraform, chef Ansible and so on…