The live host restricted 6443/tcp to specific operator addresses, added by hand,
while this role still declared the port open to Anywhere with no source
restriction. The declared config was weaker than reality: running the base role
would have REMOVED the restriction and exposed the Kubernetes API to the
internet. Security was tightened on the host and never fed back into the source
of truth.
Found 2026-08-11 while diagnosing lost cluster access, which turned out to be an
ISP lease rotation (89.244.90.246 -> .236) against a hand-maintained allowlist.
Changes:
- defaults: k3s_api_allowed_sources (empty = 6443 closed to all external
sources, the safe failure; SSH unaffected so the host stays recoverable) and
k3s_api_revoked_sources, so rotated addresses are pruned rather than left as
standing grants to whoever the ISP reassigns them to
- tasks: grant approved sources, then remove any blanket rule, then revoke
retired ones. Order matters - grants are added before the blanket rule is
deleted so convergence never opens a window with no API access
- group_vars/all.yaml: the current operator address, plus the two stale grants
(.246 rotated, 85.132.220.102 historic) marked for revocation
- docs/verification.md: state that 6443 is source-restricted rather than
listing it as a plainly allowed port
Not yet converged against the live host - the role change is committed but
running it is a production action needing operator approval.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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