https://ygg.cz/en/ A chronological stream of everything — guides, troubleshooting, notes, analyses, projects and curated external sources. en Zdeněk Kubala — CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/) https://ygg.cz/en/troubleshooting/gnome-wayland-recovery/ https://ygg.cz/en/troubleshooting/gnome-wayland-recovery/ Fri, 01 May 2026 00:00:00 GMT troubleshooting After the Debian 12 → 13 upgrade the login ends on a black screen and the session drops back to GDM. Diagnosis, the actual cause and a permanent fix. https://ygg.cz/en/guide/esp32-sensor/ https://ygg.cz/en/guide/esp32-sensor/ Wed, 01 Apr 2026 00:00:00 GMT guide From breadboard to a sensor that runs for months untouched: ESPHome firmware, MQTT discovery into Home Assistant, deep sleep + OTA. https://ygg.cz/en/reference/nftables-cheat-sheet/ https://ygg.cz/en/reference/nftables-cheat-sheet/ Sun, 01 Mar 2026 00:00:00 GMT reference The reference card taped up in my server room — commands, tables and NAT masquerade. https://ygg.cz/en/note/postfix-spf-macros/ https://ygg.cz/en/note/postfix-spf-macros/ Sun, 01 Feb 2026 00:00:00 GMT note A short note after one rough weekend of undelivered mail. https://ygg.cz/en/project/self-hosted-monitoring/ https://ygg.cz/en/project/self-hosted-monitoring/ Sun, 01 Feb 2026 00:00:00 GMT project Prometheus + Grafana across the whole home and lab infrastructure. The goal: see problems before they surface — and understand how the systems behave over time. https://ygg.cz/en/link/cadastre-open-data/ https://ygg.cz/en/link/cadastre-open-data/ Thu, 01 Jan 2026 00:00:00 GMT link The best breakdown of the dataset contents I have read so far. Worth saving. https://ygg.cz/en/explainer/dns-delegation/ https://ygg.cz/en/explainer/dns-delegation/ Thu, 01 Jan 2026 00:00:00 GMT explainer DNS is a delegated tree: every zone can hand responsibility one level down. Understand that and you understand why changes propagate slowly and where to look for faults.