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running-stabilization-loop

Use after major refactors or risky infrastructure changes to run iterative stabilization loops in kube-test: clean state, run the v3 matrix (k3s/rke2, autoscaler, leapmicro/microos, multi-arch), proactively debug failures over SSH/journalctl, apply fixes, retest until green, then validate upgrade paths from the latest tag to current staging.

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SKILL.md
Quality
Evals
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Running Stabilization Loop

Overview

Use this workflow when the goal is not only to detect failures, but to fix them and prove full regression safety after major changes.

Usage

/running-stabilization-loop

Buddy Prompt Template

Use this exact prompt when delegating the loop to another agent:

Run the full kube-hetzner v3 stabilization loop end-to-end, do not stop at pass/fail reporting.

Goals:
1) Make every matrix scenario pass from simple to complex.
2) Fix root causes in kube-hetzner (not workarounds in test harness) unless explicitly required.
3) Re-run full matrix after fixes to prove no regressions.
4) Validate upgrade path from latest git tag to current staging for both k3s and rke2.
5) When Tailscale credentials are available, include the Tailscale node-transport
   scenarios: secure single-network Tailnet access, plus Flannel with multiple
   Hetzner Networks, route auto-approval, autoscaler scale-up/down,
   `tailscale status`, and cross-network pod traffic.
6) Include final v3 polish scenarios when touched: Cilium Gateway API with
   `enable_kube_proxy=false`, embedded registry mirror on k3s or RKE2, endpoint
   output sanity, and example validation.

Hard requirements:
- Use /Users/karim/.ssh/id_ed25519 with IdentitiesOnly=yes for all SSH.
- Use /Volumes/MysticalTech/Code/kube-test/run_v3_matrix.sh and summary-*.md as source of truth.
- If RKE2/K3s apply hangs, SSH during apply and inspect journalctl/cloud-init immediately.
- If destroy hangs, run cleanup and delete stuck autoscaled servers via hcloud.
- Keep changes minimal and production-safe; run Terraform and OpenTofu validation before each rerun.
- For Tailscale node transport, verify single-network clusters work without
  route approval when route advertisement is disabled; for multinetwork, verify
  node-private routes are approved and SNAT is disabled for advertised routes.
  Do not mistake external overlay SSH access for supported Kubernetes node
  transport.
- For Cilium Gateway API, verify GatewayClass exists, Gateway is accepted, and
  HTTPRoute serves through the Hetzner LoadBalancer. For embedded registry
  mirror, verify `registries.yaml`, `embedded-registry: true`, peer ports, and
  image-pull behavior.

Deliverables:
- Final scenario matrix results with log paths.
- List of fixes made with files changed.
- Upgrade test result (tag -> staging) and any required migration notes.
- Confirmation cleanup is complete and no khv3-* resources are left.

Test Environment

  • Module code: /Volumes/MysticalTech/Code/kube-hetzner
  • Test harness: /Volumes/MysticalTech/Code/kube-test
  • Matrix runner: /Volumes/MysticalTech/Code/kube-test/run_v3_matrix.sh
  • SSH key (required): /Users/karim/.ssh/id_ed25519

Invariants

  1. Always use -o IdentitiesOnly=yes -i /Users/karim/.ssh/id_ed25519 for SSH.
  2. Always start from a clean scenario state before new loops.
  3. If any matrix scenario fails, debug and fix it before continuing.
  4. After targeted fixes, rerun the full matrix to guard against regressions.
  5. For destroy hangs with autoscaler/LB leftovers, use cleanup and hcloud deletes.
  6. Do not keep temporary broad firewall overrides after root cause is fixed.
  7. Treat scenarios_v3/summary-*.md + scenario logs/*.log as canonical run evidence.

Workflow

digraph stabilize_flow {
    rankdir=TB;
    node [shape=box];

    sync [label="1. Sync branch + terraform gates"];
    clean [label="2. Kill stale runs + cleanup state"];
    images [label="3. Verify/build required snapshots"];
    matrix [label="4. Run matrix (simple -> complex)"];
    debug [label="5. Proactive SSH/journal triage"];
    fix [label="6. Implement fix + rerun failing scenarios"];
    full [label="7. Full matrix regression rerun"];
    upgrade [label="8. Upgrade path tests (latest tag -> staging)"];
    finalize [label="9. Final cleanup + commit/push"];

    sync -> clean;
    clean -> images;
    images -> matrix;
    matrix -> debug;
    debug -> fix;
    fix -> full;
    full -> upgrade;
    upgrade -> finalize;
}

Step 1: Sync Branch and Run Gates

cd /Volumes/MysticalTech/Code/kube-hetzner
git checkout staging
git pull --ff-only origin staging
terraform fmt -recursive
terraform init -backend=false
terraform validate
tmpdir="$(mktemp -d)"
rsync -a --exclude .git --exclude .terraform --exclude .terraform-tofu ./ "$tmpdir"/
(cd "$tmpdir" && tofu init -backend=false && tofu validate)
rm -rf "$tmpdir"

cd /Volumes/MysticalTech/Code/kube-test
terraform init -upgrade

Step 2: Kill Stale Runs and Clean State

pkill -f run_v3_matrix.sh || true
pkill -f "terraform -chdir=/Volumes/MysticalTech/Code/kube-test/scenarios_v3" || true

Destroy all scenarios:

for d in \
  s1-k3s-basic \
  s2-rke2-basic \
  s3-k3s-autoscaler \
  s4-rke2-autoscaler \
  s5-leapmultiarch \
  s6-mixed-os \
  s7-kubeapi-join-lb
do
  terraform -chdir="/Volumes/MysticalTech/Code/kube-test/scenarios_v3/$d" destroy -auto-approve || true
done
find /Volumes/MysticalTech/Code/kube-test/scenarios_v3 -name ".terraform.tfstate.lock.info" -delete

If resources are stuck (especially autoscaler nodes), run:

cd /Volumes/MysticalTech/Code/kube-test
/Volumes/MysticalTech/Code/kube-hetzner/scripts/cleanup.sh

Optional alias:

alias cleanupkh='/Volumes/MysticalTech/Code/kube-hetzner/scripts/cleanup.sh'

And if autoscaled servers still exist, delete directly:

ids="$(hcloud server list -o columns=id,name | awk '/khv3-/{print $1}')"
if [ -n "$ids" ]; then
  echo "$ids" | xargs -n1 hcloud server delete
fi

Step 3: Verify Snapshot Prerequisites

Expected snapshots:

  • Leap Micro: k3s x86, k3s arm, rke2 x86, rke2 arm (4 total)
  • MicroOS: x86 + arm (2 total, optional but recommended for mixed-os scenarios)

Check:

hcloud image list --type snapshot -o columns=id,name,architecture,labels

Create missing ones from kube-test:

cd /Volumes/MysticalTech/Code/kube-test
export HCLOUD_TOKEN="$(awk -F'\"' '/hcloud_token/{print $2}' terraform.tfvars)"

packer init hcloud-leapmicro-snapshots.pkr.hcl
for distro in k3s rke2; do
  packer build -var "selinux_package_to_install=${distro}" hcloud-leapmicro-snapshots.pkr.hcl
done

packer init hcloud-microos-snapshots.pkr.hcl
packer build hcloud-microos-snapshots.pkr.hcl

Step 4: Run Matrix (Simple to Complex)

Run full matrix:

cd /Volumes/MysticalTech/Code/kube-test
RUN_ID="$(date +%Y%m%d-%H%M%S)" ./run_v3_matrix.sh | tee "scenarios_v3/matrix-${RUN_ID}.log"

Run targeted scenarios:

cd /Volumes/MysticalTech/Code/kube-test
RUN_ID="$(date +%Y%m%d-%H%M%S)" SCENARIOS="s2-rke2-basic s4-rke2-autoscaler" ./run_v3_matrix.sh

Step 5: Proactive Debugging During Runs

Do not wait for timeout-only diagnosis. SSH while apply is running if progress stalls.

Find nodes:

hcloud server list -o columns=id,name,status,ipv4 | grep khv3-

SSH:

ssh -i /Users/karim/.ssh/id_ed25519 \
  -o IdentitiesOnly=yes \
  -o StrictHostKeyChecking=no \
  -o UserKnownHostsFile=/dev/null \
  root@<node-ip>

Core checks:

systemctl is-system-running
cloud-init status --long || true
journalctl -u cloud-init -u cloud-config -u sshd --no-pager -n 200
journalctl -u k3s -u k3s-agent -u rke2-server -u rke2-agent --no-pager -n 300

RKE2-specific checks:

ls -lah /etc/rancher/rke2
cat /etc/rancher/rke2/config.yaml
systemctl cat rke2-server
systemctl cat rke2-agent

If terraform-installed scripts fail, run the exact failing commands manually and capture output (do not only read terraform stderr).

Known high-frequency failures to check first:

  1. Root SSH lock on Leap Micro:
    • Symptom: User root not allowed because account is locked
    • Check: grep '^root:' /etc/shadow
    • Fix path: packer transactional-update stage, not volatile one-off edits.
  2. Firewall/API source mismatch false negatives:
    • Symptom: cluster healthy internally but kubectl/API unreachable from runner.
    • Check runner public source vs firewall_kube_api_source.
    • Fix: use explicit allowed source in test-only scenarios, then revert broad overrides.
  3. RKE2 config/path issues:
    • Confirm module writes persistent config under /etc/rancher/rke2.
    • If a script writes to non-persistent/incorrect paths, fix module scripts and rerun.

Step 6: Fix + Targeted Rerun Loop

  1. Implement minimal fix in /Volumes/MysticalTech/Code/kube-hetzner.
  2. Run gates:
cd /Volumes/MysticalTech/Code/kube-hetzner
terraform fmt -recursive
terraform init -backend=false
terraform validate
tmpdir="$(mktemp -d)"
rsync -a --exclude .git --exclude .terraform --exclude .terraform-tofu ./ "$tmpdir"/
(cd "$tmpdir" && tofu init -backend=false && tofu validate)
rm -rf "$tmpdir"
  1. Rerun only failed scenarios:
cd /Volumes/MysticalTech/Code/kube-test
RUN_ID="$(date +%Y%m%d-%H%M%S)" SCENARIOS="<failed-scenarios>" ./run_v3_matrix.sh

Repeat until targeted failures are resolved.

Step 7: Full Regression Rerun

After targeted failures are fixed, rerun all scenarios:

cd /Volumes/MysticalTech/Code/kube-test
RUN_ID="$(date +%Y%m%d-%H%M%S)" ./run_v3_matrix.sh

No change is done until this full rerun passes.

Step 8: Upgrade Path Loop (Latest Tag -> Staging)

Build a baseline on latest tag, then upgrade to current staging code.

LATEST_TAG="$(git -C /Volumes/MysticalTech/Code/kube-hetzner tag --list 'v*' --sort=-v:refname | head -n1)"
TAG_TREE="/tmp/kube-hetzner-${LATEST_TAG}"
git -C /Volumes/MysticalTech/Code/kube-hetzner worktree add --detach "$TAG_TREE" "$LATEST_TAG"

Create an upgrade scenario from a known-good matrix scenario (repeat for both k3s and rke2):

UPG="/Volumes/MysticalTech/Code/kube-test/scenarios_v3/upgrade-k3s-${LATEST_TAG#v}"
cp -R /Volumes/MysticalTech/Code/kube-test/scenarios_v3/s1-k3s-basic "$UPG"
sed -i '' "s|source    = \"/Volumes/MysticalTech/Code/kube-hetzner\"|source    = \"$TAG_TREE\"|" "$UPG/main.tf"
terraform -chdir="$UPG" init -upgrade
terraform -chdir="$UPG" apply -auto-approve

sed -i '' "s|source    = \"$TAG_TREE\"|source    = \"/Volumes/MysticalTech/Code/kube-hetzner\"|" "$UPG/main.tf"
terraform -chdir="$UPG" init -upgrade
terraform -chdir="$UPG" plan
terraform -chdir="$UPG" apply -auto-approve
terraform -chdir="$UPG" destroy -auto-approve

Cleanup worktree:

git -C /Volumes/MysticalTech/Code/kube-hetzner worktree remove "$TAG_TREE"

Step 9: Finalize

If requested to push directly to staging:

cd /Volumes/MysticalTech/Code/kube-hetzner
git status --short
git add -A
git commit -m "fix: stabilize v3 matrix and upgrade loops"
git push origin staging

Abort/Cleanup Shortcut

pkill -f run_v3_matrix.sh || true
pkill -f "terraform -chdir=/Volumes/MysticalTech/Code/kube-test/scenarios_v3" || true
for d in /Volumes/MysticalTech/Code/kube-test/scenarios_v3/s*; do
  terraform -chdir="$d" destroy -auto-approve || true
done
find /Volumes/MysticalTech/Code/kube-test/scenarios_v3 -name ".terraform.tfstate.lock.info" -delete
Repository
mysticaltech/terraform-hcloud-kube-hetzner
Path

.claude/skills/running-stabilization-loop/SKILL.md

Commit

a8b696d

Last updated
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