func mutatePod()

in webhooks/alloydb-mutating-wh/handlers/pod_tolerations_handler.go [106:174]
65 lines of code
8 McCabe index (conditional complexity)

func mutatePod(ar *v1beta1.AdmissionReview, tols []corev1.Toleration) *v1beta1.AdmissionResponse {

	log.Info("handlers.mutatePod():Starting to add AlloyDB Omninodepool specific tolerations to the pod")
	raw := ar.Request.Object.Raw
	pod := corev1.Pod{}
	if err := json.Unmarshal(raw, &pod); err != nil {
		return &v1beta1.AdmissionResponse{
			UID:     ar.Request.UID,
			Allowed: false,
			Result: &metav1.Status{
				Message: err.Error(),
			},
		}
	}

	if pod.TypeMeta.Kind != "Pod" {
		return &v1beta1.AdmissionResponse{
			UID:     ar.Request.UID,
			Allowed: false,
			Result: &metav1.Status{
				Message: "Invalid Kind for the request, only pods are supported for mutation",
			},
		}
	}

	if len(tols) == 0 {
		return &v1beta1.AdmissionResponse{
			UID:     ar.Request.UID,
			Allowed: true,
			Result: &metav1.Status{
				Status: "Success",
			},
		}

	}
	existing := pod.Spec.Tolerations  // Existing tolerations
	combined := []corev1.Toleration{} // Existing & newly added combined
	if len(existing) == 0 {           // When no existing tolerations, combined = newly added only
		combined = tols
	} else {
		for _, t := range tols {
			if !exists(t, existing) {
				combined = append(combined, t)
			}
		}
		combined = append(combined, existing...)
	}
	patch, err := constructPatch(combined)
	if err != nil {
		log.Errorf("handlers.mutatePod():Could not create a patch for adding tolerations to the pod:: %v", err)
		return &v1beta1.AdmissionResponse{
			UID:     ar.Request.UID,
			Allowed: false,
			Result: &metav1.Status{
				Message: err.Error(),
			},
		}
	}
	log.Info("handlers.mutatePod():Added the AlloyDB Omni nodepool specific tolerations to the pod & returning the patch")
	return &v1beta1.AdmissionResponse{
		UID:     ar.Request.UID,
		Allowed: true,
		Patch:   patch,
		PatchType: func() *v1beta1.PatchType {
			pt := v1beta1.PatchTypeJSONPatch
			return &pt
		}(),
	}
}