Cannot patch new rules onto this resource

[Kezzsim]

I'm trying to make this ingress more dynamic in scripting by using kubectl's patch to add more rules, every time I want to setup a new subdomain and point to a new backend service that gets created. In theory this should be easy, just write an RFC6902 patch and apply it... easy, right?

Not so much...

Every time I run:
kubectl patch ingresses.networking.k8s.io test-ingress --type='json' -p='[{"op":"add","path":"/spec/rules/","value":{"host":"boingonetworks.test.com","http":{"paths":[{"backend":{"serviceName":"server-boingonetworks","servicePort":3003}}]}}}]'
from the cli I always get:
ingress.networking.k8s.io/test-ingress patched (no change)

Then I verify with the yml within GKE's dashboard and sure enough... no new rule under the ingress...

For the time being I will resort to reading in the ingress as JSON from kubectl -> adding to the array -> running kubectl apply on the output but I know deep down that this is vulnerable to a race condition if this gets run in multiple instances, where it could become inaccurate if it's reading in the config at the same time another entity is applying it...

[Kezzsim]

Kubectl is a little bit verbose in the way it accepts patches

I thought if I did it at position 0 it would overwrite the existing element, but instead it has the desired behavior, so the functional version of the command above is:
kubectl patch ingresses.networking.k8s.io test-ingress --type='json' -p='[{"op":"add","path":"/spec/rules/0","value":{"host":"boingonetworks.test.com","http":{"paths":[{"backend":{"serviceName":"server-boingonetworks","servicePort":3003}}]}}}]'