Background
The SSL conflict detector currently runs only in the admission webhook (ValidateCreate / ValidateUpdate for Gateway, Ingress, ApisixTls). apisix-ingress-controller#2810 / api7-ingress-controller#437 changed it from denying an overlapping SSL object to emitting an admission warning, because denial was both incomplete and a backward-compatibility break (an unrelated edit to an object that already coexists with an overlapping one got rejected).
Warning at admission is only a partial answer. This issue tracks moving to a reconcile-time, Gateway-API-aligned model.
Why admission-time detection is insufficient
The webhook only fires on object create/update, so it never sees conflicts that arise from:
- a certificate rotating inside its Secret (two previously-agreeing objects diverge, no object event),
- a
GatewayProxy / IngressClass change moving an object into a different group,
- the webhook being disabled (
failurePolicy: Ignore),
- objects created before the webhook was installed.
None of these produce any signal today.
Proposed direction (Gateway API OverlappingTLSConfig)
Gateway API specifies that overlapping SNIs are allowed, with the data plane serving the longest matching SNI, and v1.3 defines the OverlappingTLSConfig listener condition that controllers MUST set on overlapping listeners, with a documented tie-break (oldest creationTimestamp, then namespace/name).
Scope note
This is the reconcile-side follow-up to the warn-only detector in #437 / apisix-ingress#2810. Should be synced to apisix-ingress-controller as well once the design is agreed.
Background
The SSL conflict detector currently runs only in the admission webhook (
ValidateCreate/ValidateUpdatefor Gateway, Ingress, ApisixTls). apisix-ingress-controller#2810 / api7-ingress-controller#437 changed it from denying an overlapping SSL object to emitting an admission warning, because denial was both incomplete and a backward-compatibility break (an unrelated edit to an object that already coexists with an overlapping one got rejected).Warning at admission is only a partial answer. This issue tracks moving to a reconcile-time, Gateway-API-aligned model.
Why admission-time detection is insufficient
The webhook only fires on object create/update, so it never sees conflicts that arise from:
GatewayProxy/IngressClasschange moving an object into a different group,failurePolicy: Ignore),None of these produce any signal today.
Proposed direction (Gateway API
OverlappingTLSConfig)Gateway API specifies that overlapping SNIs are allowed, with the data plane serving the longest matching SNI, and v1.3 defines the
OverlappingTLSConfiglistener condition that controllers MUST set on overlapping listeners, with a documented tie-break (oldestcreationTimestamp, thennamespace/name).sslutil.HostsOverlap/ClientConfigHashlogic.OverlappingTLSConfig; define an equivalent for ApisixTls / Ingress).creationTimestamp; thennamespace/name) so operators know which certificate wins.Scope note
This is the reconcile-side follow-up to the warn-only detector in #437 / apisix-ingress#2810. Should be synced to apisix-ingress-controller as well once the design is agreed.