Files
PFVCluster/k8s
mrcharles bad40feae6 feat(k8s): add worker join script + 6 worker nodes to env config
- env.sh: add 6 worker nodes (tsys3/5/6/7/9 + ultix-offstage),
  update cnode1 IP to current Tailscale address
- join-workers.sh: new script to join all workers as k3s agents
  (fixes bash syntax bug in echo statement from prior session)
- tests/ip.sh: pass-through wrapper for ip command

[#367] [#368]
2026-08-06 13:11:43 -05:00
..

k8s/ — pfv-k8s Cluster Setup Scripts

Redmine: #362 (initial build, closed) · #367 (rebuild, open) · #368 (worker join, open)

Scripts to bootstrap and manage the k3s control plane on cnode1/2/3. All cluster communication goes over Tailscale IPs — no LAN traffic.

Current State

3-node HA control plane (k3s v1.36.2+k3s1, embedded etcd):

Node Tailscale IP Role Tainted
pfv-k8s-cnode1 100.97.178.106 control-plane, etcd NoSchedule
pfv-k8s-cnode2 100.109.34.72 control-plane, etcd NoSchedule
pfv-k8s-cnode3 100.106.222.18 control-plane, etcd NoSchedule

Scripts

Script Purpose
env.sh Shared config: node IPs, SSH opts, k3s version. Sourced by all scripts.
wipe.sh Remove existing k3s from all cnodes (clean slate).
install-cp.sh Full bootstrap: cnode1 (--cluster-init) then cnode2/3 join.
join-servers.sh Re-join cnode2/3 only (if cnode1 is already up).
post-setup.sh Apply NoSchedule taints, fetch kubeconfig, verify.
verify.sh Health check: nodes Ready, Tailscale IPs, taints, etcd, CoreDNS.
probe-nodes.sh Verify SSH + Tailscale reachability.

Usage

# Full bootstrap from scratch:
bash k8s/wipe.sh
bash k8s/install-cp.sh
bash k8s/post-setup.sh
bash k8s/verify.sh

# Access the cluster:
export KUBECONFIG=~/.kube/config.pfv-k8s
kubectl get nodes

Design Decisions

  • k3s (not Talos): This is a regular R&D cluster, not ITAR/classified. Talos architecture is documented in docs/ for when that requirement comes online. k3s on stock Debian is simpler to operate.
  • Tailscale-only transport: --node-ip, --advertise-address, and --tls-san are all set to Tailscale IPs. No LAN IP appears in any node status or certificate.
  • VXLAN flannel: Pods communicate via flannel VXLAN overlay on top of Tailscale's WireGuard. Double-encrypted, but functional and reliable.
  • NoSchedule taint: All 3 cnodes are tainted so no user workloads schedule on the control plane. Only system components (CoreDNS, metrics-server, flannel, kube-proxy) with built-in tolerations run here.
  • Embedded etcd: 3-node HA etcd quorum. Tolerates 1 node failure.