feat(conformance): L0 guard that the external-dns annotationPrefix matches the tree
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Add assertion (8) to internal-services-publish-no-public-dns. The external-dns
HelmRelease must declare annotationPrefix explicitly, and every
external-dns annotation in apps/, platform/, runbooks/ and catalog/render.py
must use that prefix. The v0.23.0 default-prefix change on 2026-11-07
ignored the controller: none, target and hostname annotations while
assertions (1)-(3) stayed green.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
This commit is contained in:
jakman85andClaude Opus 5.5 committed 2026-11-07 17:56:12 -06:00
1 parent 267446c68f
commit 9c51f60a35
2 files changed
+128 -6

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@@ -26,7 +26,10 @@
# KNOWN_NON_CATALOG_PUBLISHERS — shrink-only, stale entries FAIL;
# (7) the check is LOAD-BEARING: whole-repo scope declared in chainsaw-test.yaml, honoured by
# ci/l0.sh's --include-scope union, and ci/gate.sh blocks on an l0 failure. NO hand-written
# ci/l0.sh stage (whole-repo-invariants-wired fails the gate if one appears).
# ci/l0.sh stage (whole-repo-invariants-wired fails the gate if one appears);
# (8) the external-dns HelmRelease declares `annotationPrefix` explicitly and it matches the
# prefix of EVERY external-dns annotation in the tree and in catalog/render.py — added after
# the 2026-11-07 v0.23.0 default-prefix change silently voided (1)-(3) at runtime.
#
# WHAT THIS DOES *NOT* PROVE (honest gaps — it is STATIC, offline, cluster-free):
# - That the record is gone from Cloudflare. Live read; belongs beside
@@ -90,9 +93,18 @@ CHECKS = 0
# ControllerValue = "dns-controller" -> the value that CLAIMS an object
# source/annotations/processors.go IsControllerMismatch skips a source object when the key is
# PRESENT and the value is NOT ControllerValue. So "disowned" == key present, value != claimed.
CONTROLLER_KEY = "external-dns.alpha.kubernetes.io/controller"
#
# THE PREFIX IS NOT A CONSTANT OF NATURE. Every key external-dns reads is `<annotationPrefix><name>`,
# and the prefix is a runtime flag whose DEFAULT moved in v0.22.0 (#6424: alpha -> GA, "with no
# fallback"). On 2026-11-07 the chart bump to v0.23.0 made every key below invisible to the running
# controller while this check — which only asserted the keys were PRESENT — stayed green. (8) now
# ties ANNOTATION_PREFIX to the HelmRelease's explicit `annotationPrefix`.
ANNOTATION_PREFIX = "external-dns.alpha.kubernetes.io/"
CONTROLLER_KEY = ANNOTATION_PREFIX + "controller"
CONTROLLER_CLAIMED = "dns-controller"
HOSTNAME_KEY = "external-dns.alpha.kubernetes.io/hostname"
HOSTNAME_KEY = ANNOTATION_PREFIX + "hostname"
# Any key that looks like an external-dns annotation, under ANY prefix variant (alpha, GA, typos).
EXTERNAL_DNS_KEY_RE = re.compile(r"^external-dns(\.[a-z0-9-]+)*\.kubernetes\.io/")
def check(cond, msg):
@@ -231,9 +243,7 @@ for sub in SCAN_DIRS:
ann = md.get("annotations") or {}
if kind == "HTTPRoute":
routes.append((rel, d))
elif kind == "Service" and any(
a.startswith("external-dns.alpha.kubernetes.io/") for a in ann
):
elif kind == "Service" and any(EXTERNAL_DNS_KEY_RE.match(a) for a in ann):
dns_services.append((rel, d))
check(len(routes) > 0, "inventory: no HTTPRoute found under apps/ platform/ runbooks/ — parse "
@@ -444,6 +454,67 @@ check(
"and the whole-repo-invariants-wired meta-test fails the gate on a hand-written stage.",
)
# =============================================================================================
# (8) THE RUNNING CONTROLLER READS THE PREFIX THIS TREE WRITES.
# (a) the external-dns HelmRelease sets `values.annotationPrefix` EXPLICITLY (an upstream
# default is exactly what moved under us) and it equals ANNOTATION_PREFIX;
# (b) it does not ALSO enable `--enable-legacy-annotation-prefix` (dual-read hides a
# half-migration; upstream says the flag will be removed);
# (c) every external-dns-looking annotation key on any object under apps/ platform/ runbooks/
# uses ANNOTATION_PREFIX — a key under another prefix is silently ignored at runtime;
# (d) catalog/render.py emits no external-dns key under another prefix.
# Migrating to the GA prefix = change ANNOTATION_PREFIX, the HelmRelease value, the renderer
# and every manifest in ONE commit; this assertion fails on any partial state.
# =============================================================================================
HR_PATH = ROOT / "platform/externaldns/helmrelease.yaml"
hr = next((d for d in docs_of(HR_PATH) if d.get("kind") == "HelmRelease"
and (d.get("metadata") or {}).get("name") == "external-dns"), None)
check(hr is not None, f"(8) {HR_PATH.relative_to(ROOT)} holds no HelmRelease `external-dns` — "
f"cannot prove which annotation prefix the controller reads")
values = ((hr or {}).get("spec") or {}).get("values") or {}
hr_prefix = values.get("annotationPrefix")
check(
hr_prefix == ANNOTATION_PREFIX,
f"(8a) external-dns HelmRelease `values.annotationPrefix` is {hr_prefix!r}, but every "
f"external-dns annotation in this tree uses {ANNOTATION_PREFIX!r}. A mismatch (or relying on "
f"the upstream default, which changed in v0.22.0) makes the controller IGNORE `controller: "
f"none`, the Gateway `target` and Service `hostname` — internal names go public, public names "
f"answer RFC1918 (incident 2026-11-07).",
)
extra = values.get("extraArgs") or []
extra_s = " ".join(f"{k}={v}" for k, v in extra.items()) if isinstance(extra, dict) \
else " ".join(map(str, extra))
check("enable-legacy-annotation-prefix" not in extra_s and "annotation-prefix" not in extra_s,
"(8b) external-dns extraArgs must not set --annotation-prefix or "
"--enable-legacy-annotation-prefix; the prefix is declared ONLY via values.annotationPrefix "
"so this check can see it")
foreign: list[str] = []
seen_keys = 0
for sub in SCAN_DIRS:
base = ROOT / sub
if not base.is_dir():
continue
for p in sorted(base.rglob("*.yaml")):
rel = p.relative_to(ROOT).as_posix()
for d in docs_of(p):
for k in annotations_of(d):
if isinstance(k, str) and EXTERNAL_DNS_KEY_RE.match(k):
seen_keys += 1
if not k.startswith(ANNOTATION_PREFIX):
foreign.append(f"{rel}:{'/'.join(ident(d))} {k}")
check(seen_keys > 0, "(8c) no external-dns annotation found anywhere — parse contract broken "
"(the Gateway target alone guarantees at least one)")
check(not foreign,
f"(8c) external-dns annotations under a prefix the controller does NOT read "
f"({ANNOTATION_PREFIX!r} is configured): {foreign}")
render_src = read(CATALOG / "render.py")
bad_render = sorted({m for m in re.findall(r"external-dns(?:\.[a-z0-9-]+)*\.kubernetes\.io/",
render_src) if m != ANNOTATION_PREFIX})
check(not bad_render,
f"(8d) catalog/render.py emits external-dns keys under {bad_render}, but the controller "
f"reads {ANNOTATION_PREFIX!r}")
# =============================================================================================
if FAILURES:
for f in FAILURES: