Add missing metav1.ObjectMeta to NetworkPolicyEvaluation API type (#6675

)

It seems that omitting the field was a mistake when defining the API.
New versions of the K8s code generators (client-gen specifically) will
not work with types missing this field.
See kubernetes/code-generator@688a73a
This is preventing us from updating to a more recent version of the K8s
libraries and of the code generators.

Note that I believe that this API was modeled after the upstream
TokenReview API (which like this one only supports the "create" verb,
and returns a response immediately). The TokenReview type does include a
metav1.ObjectMeta field.

Unfortunately, for backwards-compatibility, we need to use Protobuf
field number 3 for the metadata field, while K8s always uses 1. This is
a bit surprising, but it should only affect the wire format, and nothing
else.

Signed-off-by: Antonin Bas <[email protected]>

pkg/apis/controlplane/types.go

@@ -453,6 +453,7 @@ type NetworkPolicyNodeStatus struct {
 // NetworkPolicyEvaluation contains the request and response for a NetworkPolicy evaluation.
 type NetworkPolicyEvaluation struct {
 	metav1.TypeMeta
+	metav1.ObjectMeta
 	Request  *NetworkPolicyEvaluationRequest
 	Response *NetworkPolicyEvaluationResponse
 }

pkg/apis/controlplane/v1beta2/types.go

@@ -458,8 +458,16 @@ type NetworkPolicyNodeStatus struct {
 // NetworkPolicyEvaluation contains the request and response for a NetworkPolicy evaluation.
 type NetworkPolicyEvaluation struct {
 	metav1.TypeMeta `json:",inline"`
-	Request         *NetworkPolicyEvaluationRequest  `json:"request,omitempty" protobuf:"bytes,1,opt,name=request"`
-	Response        *NetworkPolicyEvaluationResponse `json:"response,omitempty" protobuf:"bytes,2,opt,name=response"`
+	// ObjectMeta was omitted by mistake when this type was first defined, and was added later on.
+	// To ensure backwards-compatibility, we had to use Protobuf field number 3 when adding the
+	// field, as 1 was already taken by the request field. This is unusual, as K8s API types
+	// always use 1 as the Protobuf field number for the metadata field, and that's also what we
+	// do for all other Antrea API types. It should only affect the wire format, and nothing else.
+	// When a new version of this API is introduced in the future (e.g., v1), we can correct
+	// this and assign 1 as the Protobuf field number for the metadata field.
+	metav1.ObjectMeta `json:"metadata,omitempty" protobuf:"bytes,3,opt,name=metadata"`
+	Request           *NetworkPolicyEvaluationRequest  `json:"request,omitempty" protobuf:"bytes,1,opt,name=request"`
+	Response          *NetworkPolicyEvaluationResponse `json:"response,omitempty" protobuf:"bytes,2,opt,name=response"`
 }
 
 // Entity contains Namespace and Pod name as a request parameter.