Some update transitions terminally error out

[euank]

What happened

There are a number of updates that do not work and result in the ingress being stuck in a broken state.

I'll list a few, but I expect there are quite a few more:

IPolicy duplicate-ish rules

Applying the following diff:

 apiVersion: ingress.k8s.ngrok.com/v1alpha1
 kind: IPPolicy
 metadata:
   name: test-policy
 spec:
   rules:
-  - action: allow
+  - action: deny
     cidr: 127.0.0.1/32

results in the terminal error:

2023-05-11T07:57:48Z	ERROR	Reconciler error	{"controller": "ippolicy", "controllerGroup": "ingress.k8s.ngrok.com", "controllerKind": "IPPolicy", "IPPolicy": {"name":"test-policy","namespace":"default"}, "namespace": "default", "name": "test-policy", "reconcileID": "3d692c18-9bd3-4275-b2d3-ed559c612093", "error": "HTTP 400: IP Policy Rule with CIDR '127.0.0.1/32' already exists [ERR_NGROK_1408]\n\nOperation ID: op_2PdfRGQmUcjcjXkqIRnvGASQQyr"}

even though the start and end states are both valid IP Policies.

OIDC->OAuth

Creating an edge with a valid OIDC config, and then deleting the OIDC config and replacing it with an OAuth config (in one kubectl apply) is a transition from a valid state to a valid state, but terminally errors out with:

2023-05-11T08:19:52Z	ERROR	Reconciler error	{"controller": "httpsedge", "controllerGroup": "ingress.k8s.ngrok.com", "controllerKind": "HTTPSEdge", "HTTPSEdge": {"name":"euank-test-ingress-ngrok-app","namespace":"default"}, "namespace": "default", "name": "euank-test-ingress-ngrok-app", "reconcileID": "35cc5666-885a-4215-acc2-0ac70ee6b893", "error": "HTTP 400: The edge specifies conflicting authentication modules. Only one of SAML, OIDC, or OAuth may be enabled. [ERR_NGROK_7079]\n\nOperation ID: op_2Pdi7YrFWhVcycMnDATcHy57itM"}

Changing route path-type

 apiVersion: networking.k8s.io/v1
 kind: Ingress
 metadata:
   name: test
 spec:
   ingressClassName: ngrok
   rules:
     - host: euank-test-ingress.ngrok.app
       http:
         paths:
           - path: /
-            pathType: Prefix
+            pathType: Exact
             backend:
               service:
                 name: test
                 port:
                   number: 80

The above is a transition from a valid state to a valid state, but applying that diff results in the terminal:

2023-05-11T08:27:19Z	ERROR	Reconciler error	{"controller": "httpsedge", "controllerGroup": "ingress.k8s.ngrok.com", "controllerKind": "HTTPSEdge", "HTTPSEdge": {"name":"euank-test-ingress-ngrok-app","namespace":"default"}, "namespace": "default", "name": "euank-test-ingress-ngrok-app", "reconcileID": "046c3afe-8063-495c-b0ec-e46b3794b7b7", "error": "HTTP 400: Route match expression '/' must be unique across all routes for HTTPS edge. [ERR_NGROK_7126]\n\nOperation ID: op_2Pdj1l1rOGnAAqEWlFdRWxsMjkd"}

What you think should happen instead

All of the above transitions are from a valid configuration to a valid configuration, so they should work.