First run of the 3-server harness: the config path works (VMs boot, config.yaml
rendered by the production generator, k3s installs, etcd forms), but three full
control-plane servers starved etcd of CPU on a labsim host running 18 VMs (load
8+). etcd lost leader continuously -> "storage is (re)initializing" -> k3s stuck
activating -> datastore reset. Not a harness bug; host capacity + etcd's latency
intolerance.
Fixes for a clean next run:
- LAB-ONLY etcd tuning (heartbeat-interval=500, election-timeout=5000) in the
install exec, clearly marked as not-production and not affecting what the
conversion test exercises -- the standard remedy for etcd under nested-virt.
- Shut the other labsim k8s/dualstack VMs before `up` (done at teardown).
Also fixed a real sim drift found en route: the sim MASTER router lacked the NAT
masquerade rules the backup had, so LAN had no internet whenever .253 was master.
Added masquerade for 172.31.0.0/16 out bond0.53 + pppoe0.
Full write-up: labsim/dualstack-evidence/etcd-harness-2026-09-07.md.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DMVzWZgiKW2wquf5z8S1yH
The rehearsal vehicle for cluster dual-stack. Unlike k8s-up.sh (1 server + 2
agents, inline INSTALL_K3S_EXEC), this builds 3 control-plane servers with
embedded etcd, each configured through /etc/rancher/k3s/config.yaml rendered by
labctl's own generate*Config via bin/render-config.js -- the exact production
code path. Node 1 cluster-inits; 2/3 join as etcd members (role=infra + server
URL, same shape as production worker1/worker2).
Carries the audit-policy.yaml the generated config references (byte-identical to
audit-policy.ts) -- without it the apiserver silently crash-loops. Validates the
embedded config.yaml as YAML before building each seed ISO.
Next: rehearse the dual-stack conversion on it (rolling config.yaml change,
quorum, mixed control plane, ServiceCIDR pickup).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DMVzWZgiKW2wquf5z8S1yH
