Reject VS/VSR resources with enabled plus features for OSS

pkg/apis/configuration/validation/validation.go

@@ -373,6 +373,7 @@ func validateUpstreams(upstreams []v1alpha1.Upstream, fieldPath *field.Path, isP
 		allErrs = append(allErrs, validateTime(u.SlowStart, idxPath.Child("slow-start"))...)
 		allErrs = append(allErrs, validateBuffer(u.ProxyBuffers, idxPath.Child("buffers"))...)
 		allErrs = append(allErrs, validateSize(u.ProxyBufferSize, idxPath.Child("buffer-size"))...)
+		allErrs = append(allErrs, rejectPlusResourcesInOSS(u, idxPath, isPlus)...)
 
 		for _, msg := range validation.IsValidPortNum(int(u.Port)) {
 			allErrs = append(allErrs, field.Invalid(idxPath.Child("port"), u.Port, msg))
@@ -796,3 +797,21 @@ func validateVirtualServerRouteSubroutes(routes []v1alpha1.Route, fieldPath *fie
 
 	return allErrs
 }
+
+func rejectPlusResourcesInOSS(upstream v1alpha1.Upstream, idxPath *field.Path, isPlus bool) field.ErrorList {
+	allErrs := field.ErrorList{}
+
+	if isPlus {
+		return allErrs
+	}
+
+	if upstream.HealthCheck != nil {
+		allErrs = append(allErrs, field.Forbidden(idxPath.Child("healthCheck"), "active health checks are only supported in NGINX Plus"))
+	}
+
+	if upstream.SlowStart != "" {
+		allErrs = append(allErrs, field.Forbidden(idxPath.Child("slow-start"), "slow start is only supported in NGINX Plus"))
+	}
+
+	return allErrs
+}

pkg/apis/configuration/validation/validation_test.go

@@ -1992,3 +1992,22 @@ func TestValidateIntFromStringFails(t *testing.T) {
 		t.Errorf("validateIntFromString() returned no errors for invalid input %v", input)
 	}
 }
+
+func TestRejectPlusResourcesInOSS(t *testing.T) {
+	upstream := v1alpha1.Upstream{
+		SlowStart:   "10s",
+		HealthCheck: &v1alpha1.HealthCheck{},
+	}
+
+	allErrsPlus := rejectPlusResourcesInOSS(upstream, field.NewPath("upstreams").Index(0), true)
+	allErrsOSS := rejectPlusResourcesInOSS(upstream, field.NewPath("upstreams").Index(0), false)
+
+	if len(allErrsPlus) != 0 {
+		t.Errorf("rejectPlusResourcesInOSS() returned errors %v for NGINX Plus for upstream %v", allErrsPlus, upstream)
+	}
+
+	if len(allErrsOSS) == 0 {
+		t.Errorf("rejectPlusResourcesInOSS() returned no errors for NGINX OSS for upstream %v", upstream)
+	}
+
+}