Update ObservabilityPolicy API to have minimum one target ref (nginx#2753)

Update Observability API to have one minimum one target ref

Problem: User wants ObservabilityPolicy CRD should require a minimum of 1 TargetRef.

Solution: Add validation to have minimum one target ref for the ObservabilityPolicy CRDs.

Author: miledxz

apis/v1alpha1/observabilitypolicy_types.go

@@ -47,6 +47,7 @@ type ObservabilityPolicySpec struct {
 	// Objects must be in the same namespace as the policy.
 	// Support: HTTPRoute, GRPCRoute.
 	//
+	// +kubebuilder:validation:MinItems=1
 	// +kubebuilder:validation:MaxItems=16
 	// +kubebuilder:validation:XValidation:message="TargetRef Kind must be: HTTPRoute or GRPCRoute",rule="(self.exists(t, t.kind=='HTTPRoute') || self.exists(t, t.kind=='GRPCRoute'))"
 	// +kubebuilder:validation:XValidation:message="TargetRef Group must be gateway.networking.k8s.io.",rule="self.all(t, t.group=='gateway.networking.k8s.io')"

config/crd/bases/gateway.nginx.org_observabilitypolicies.yaml

@@ -85,6 +85,7 @@ spec:
                   - name
                   type: object
                 maxItems: 16
+                minItems: 1
                 type: array
                 x-kubernetes-validations:
                 - message: 'TargetRef Kind must be: HTTPRoute or GRPCRoute'

deploy/crds.yaml

@@ -904,6 +904,7 @@ spec:
                   - name
                   type: object
                 maxItems: 16
+                minItems: 1
                 type: array
                 x-kubernetes-validations:
                 - message: 'TargetRef Kind must be: HTTPRoute or GRPCRoute'