Trigger implementation completes the kubeconfig Generator's interface
conformance. Behavior matches spec §9.5 + §8.5 defense-in-depth:
- ALWAYS returns 403 + Kubernetes-shaped Status JSON (whether the
token is valid or not). Attackers cannot distinguish "valid
token, no permission" from "no such token" by status code or
response shape — both are 403 with byte-identical structure modulo
the resource/verb message slot.
- Status JSON conforms to k8s.io Status object: kind=Status,
apiVersion=v1, metadata={}, status=Failure, reason=Forbidden,
code=403, message=verisimilar real-kubectl error string.
- Message format mirrors kubectl's actual output:
<resource> is forbidden: User "system:anonymous" cannot <verb>
resource "<resource>" in API group "" in the namespace "default"
where <resource> is the last segment of r.URL.Path and <verb> is
derived from the HTTP method (GET/HEAD → list, POST → create, PUT
→ update, PATCH → patch, DELETE → delete, others → list). This is
richer than spec §9.5's hardcoded "list" — kubectl ships the verb
based on the action it's attempting, so a /apis/.../pods DELETE
response saying "cannot list" would tip the attacker off. Method
mapping is forensic gold for the operator (which kubectl action
actually fired) and verisimilar to the attacker.
- Event.Extra captures the kubectl_path / kubectl_method /
kubectl_query / kubectl_ua fields per spec §9.5 line 1234. UA
capture is the forensic prize — kubectl ships its version + arch
in the UA string ("kubectl/v1.30.0 (linux/amd64) kubernetes/...").
- Source-IP triplet (realIP / lastNonEmptyXFF / optionalHeader) is
a content-copy of webbug/docx/pdf — sanctioned duplication per
Phase 2/3/4 anti-relitigation set. Phase 9 middleware extraction
collapses these into one shared helper.
- Nil-token path returns the same 403+Status with verisimilar
message + headers, and nil event so the handler cannot persist
a row with empty TokenID (FK violation) — spec §8.5.
Tests cover (~36 cases including subtests):
- 403 + JSON content-type + cache headers
- Status JSON shape (Kind/APIVersion/metadata={}/Status/Reason/Code)
- Message resource extraction: pods, secrets, single-resource get,
API version probe, trailing slash, healthz probe (6 paths)
- Verb derivation from HTTP method (7 methods, 5 distinct verbs)
- User "system:anonymous" impersonation present
- kubectl_path/method/query/ua in Extra JSON
- Empty query string handled
- Source-IP precedence (11 subcases mirroring docx/pdf for parity)
- Missing UA/Referer → nil pointers
- Nil-token defense-in-depth: still returns 403 + parseable Status,
nil event, response-shape parity with valid-token case (HTTP code
+ JSON kind/version/status/reason/code all identical so an
attacker cannot probe token validity by diffing responses)
Generator now satisfies generators.Generator interface. Registry wire-up
in next commit.