K3s

TL;DR Grafana went completely dark for about 26 hours on my home k3s cluster. Two things broke simultaneously: Loki entered CrashLoopBackOff, and Prometheus silently stopped ingesting metrics — its pods showed as healthy and 2/2 Running the whole time. The actual cause was Longhorn’s auto-balancer migrating replicas onto a freshly-added cluster node (k3s-agent-4) that had unstable storage during its first 48 hours. The replica I/O errors propagated directly into the workloads, corrupting mid-write files: a Prometheus WAL segment and a Loki TSDB index file. Both required offline surgery via a busybox pod to delete the corrupted files before the services could recover. ...

TL;DR Upgraded a production k3s cluster from v1.29.0+k3s1 to v1.34.4+k3s1 across 8 nodes — 3 control plane servers, 4 amd64 worker agents, and 1 arm64 Lima VM agent. The upgrade stepped through every minor version (v1.29 → v1.30 → v1.31 → v1.32 → v1.33 → v1.34) with etcd snapshots between each step. Longhorn was upgraded from v1.6.0 to v1.8.2 in two stages (v1.7.3 as an intermediate step). SSH was broken to all cluster nodes, so the entire upgrade was done via Proxmox QEMU Guest Agent (qm guest exec) and Lima CLI (limactl shell). Discovered that k3s intentionally pins Traefik to v2.11.24 even when bundling Helm chart v27 — Traefik v3 migration is a separate effort. ...

TL;DR Day two of the cluster was a marathon. I deployed two full-stack applications (Cardboard TCG tracker and Trade Bot), set up PostgreSQL with Longhorn persistent storage, created a cluster dashboard, configured Prometheus service monitors, built a dev workspace for remote SSH, and scaled the ARC runners. By the end, the cluster was running real workloads and I had a proper development workflow. The Deployment Pattern Before diving into the applications, I established a consistent deployment pattern that every service follows: ...

TL;DR Today was cluster genesis. Starting from 3 bare Proxmox hosts, I built the entire infrastructure-as-code pipeline: Terraform to provision VMs from cloud-init templates, Ansible to configure and bootstrap k3s, and a full GitOps deployment model with SOPS-encrypted secrets and S3-backed Terraform state. By end of day: 3 server nodes, 3 agent nodes, cert-manager with Route53 DNS-01 validation, and self-hosted GitHub Actions runners on the cluster itself. The Architecture The design goal was simple: everything as code, nothing manual, everything reproducible. ...