experiment: add message to allowed admission response

Signed-off-by: Alexander Yastrebov <alexander.yastrebov@zalando.de>

cmd/webhook/admission/definitions.go

@@ -47,10 +47,12 @@ type admissionRequest struct {
  Object json.RawMessage `json:"object,omitempty"`
 }
 
+// See https://pkg.go.dev/k8s.io/api/admission/v1#AdmissionResponse
 type admissionResponse struct {
- UID string `json:"uid"`
- Allowed bool `json:"allowed"`
- Result *status `json:"status,omitempty"`
+ UID string `json:"uid"`
+ Allowed bool `json:"allowed"`
+ Result *status `json:"status,omitempty"`
+ Warnings []string `json:"warnings,omitempty"`
 }
 
 type status struct {

cmd/webhook/admission/routegroup.go

@@ -28,6 +28,17 @@ func (rga *RouteGroupAdmitter) admit(req *admissionRequest) (*admissionResponse,
  }, nil
  }
 
+ if rgItem.Metadata.Name == "admission-test" {
+ return &admissionResponse{
+ UID: req.UID,
+ Allowed: true,
+ Warnings: []string{
+ "This is a test warning1, see https://opensource.zalando.com/skipper/kubernetes/routegroups/",
+ `Argument "foo" is not allowed for filter fooBarBazQux due to whatever, see https://opensource.zalando.com/skipper/kubernetes/routegroups/ for details.`,
+ },
+ }, nil
+ }
+
  return &admissionResponse{
  UID: req.UID,
  Allowed: true,