Delay in SecurityPolicy change propagation for HTTPRoute when using targetSelectors

[luvk1412]

I am facing a delay in propagation of security policy when I change from one security policy to another security policy in a situation when security policy is applied to http-routes using labels.

I have tried few things to narrow down the cases in which it is happening:
Suppose i have following resources :

• sp-1 having targetSelectors for HTTPRoute as sp: sp-1
• sp-2 having targetSelectors for HTTPRoute as sp: sp-2
• HTTPRoute : route-1

Then for above:

• If route-1 has sp-1 applied via labels: sp: sp-1 and now if I change the labels to sp: sp-2 (to apply sp-2 to route-1), then it takes considerable amount of time for this change to propagate. I am verifying if changes are propagated or not via egctl c envoy-proxy route
• if route-1 has sp-1 applied via labels: sp: sp-1, and if i make some change in sp-1 itself and apply, the policy change is immediately propagated in route as well.
• if route-1 has sp-1 applied via targetRefs for route-1 in sp-1, then making change in policy or shifting targetRefs to sp-2, both changes immediately propagate.

So basically only in the first case, where policy is applied to a route via targetSelectors and we change from one predefined security policy to another predefined one, i see a delay in propagation and delay can be of minutes also. I want to know if this delay is expected and if yes is there a way to reduce it.

This is reproducible on my local using latest dev eg version.

[arkodg]

thanks for finding this @luvk1412 !
looks like the current predicate only takes ObservedGeneration into consideration

gateway/internal/provider/kubernetes/controller.go

Line 1105 in d00737b

// Watch HTTPRoute CRUDs and process affected Gateways.

we probably also need to reconcile when the route labels change

[arkodg]

Seems like a simpler fix, need to add https://pkg.go.dev/sigs.k8s.io/controller-runtime/pkg/predicate#LabelChangedPredicate, @luvk1412 interested in taking a stab at it ?

[luvk1412]

@arkodg sure why not, can give this a try. you can assign to me.