Files
home-network-k3s-impl/infra/ansible/roles/node_health/files
jakman85andClaude Opus 5 9d00a3fcd3 fix(node_health): memory.swap blamed the wrong thing, and could not see the defect
The WARN read "roles/node_baseline runs swapoff and neutralises the fstab entry;
this node has not been baselined yet". That was a MIS-DIAGNOSIS. All three prod
nodes HAD been baselined, had their fstab swap line commented out by the role, and
were still swapping 977 MiB each after a reboot. Anyone reading that WARN would
have re-run the role that had already run, and watched swap come back next boot.

The detail now names the actual mechanism — systemd-gpt-auto-generator re-creating
a .swap unit from the partition TYPE GUID 0657fd6d-a4ab-43c4-84e5-0933c84b4f4f at
every boot, without reading /etc/fstab — says in as many words that this is not
"the node has not been baselined", and points at `node-baseline.yml --tags system`.

The check was also blind in the other direction: SwapTotal == 0 is not evidence
that swap is disabled, only that nothing has been swapped on yet this boot, so a
node freshly swapoff-ed PASSed while still set to swap again on reboot — exactly
the state the old role left behind. The collector now reports memory.swap_persistence
(swap.target masked?, .swap units the generators emitted this boot, which of them
are masked, leftover active fstab swap lines — all world-readable, no root, no
systemctl parsing), and the check WARNs on "clean now, swapping after the next
reboot".

Rendered against every fact shape (swap active + unmasked, swap off + unmasked,
after the fix, a dev VM with no swap partition at all, per-unit mask only,
persistence unreadable, an older collector's output with the key absent, and
/proc/meminfo unreadable) and verified live on k3s-prod-1 post-reboot:
  [PASS] memory.swap — no swap active and none can be activated: swap.target is masked

Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-07 22:35:31 -05:00
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