Use Patch instead of Update in the daemonset_controller when scaling

Signed-off-by: Aurel Canciu <[email protected]>

pkg/canary/daemonset_controller.go

@@ -18,6 +18,7 @@ package canary
 
 import (
  "context"
+ "encoding/json"
  "fmt"
 
  "go.uber.org/zap"
@@ -26,6 +27,7 @@ import (
  "k8s.io/apimachinery/pkg/api/errors"
  metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
  "k8s.io/apimachinery/pkg/runtime/schema"
+ "k8s.io/apimachinery/pkg/types"
  "k8s.io/client-go/kubernetes"
  "k8s.io/client-go/util/retry"
 
@@ -34,7 +36,7 @@ import (
 )
 
 var (
- daemonSetScaleDownNodeSelector = map[string]string{"flagger.app/scale-to-zero": "true"}
+ daemonSetScaleDownNodeSelector = map[string]interface{}{"flagger.app/scale-to-zero": "true"}
 )
 
 // DaemonSetController is managing the operations for Kubernetes DaemonSet kind
@@ -54,39 +56,35 @@ func (c *DaemonSetController) ScaleToZero(cd *flaggerv1.Canary) error {
  return fmt.Errorf("daemonset %s.%s get query error: %w", targetName, cd.Namespace, err)
  }
 
- daeCopy := dae.DeepCopy()
- daeCopy.Spec.Template.Spec.NodeSelector = make(map[string]string,
- len(dae.Spec.Template.Spec.NodeSelector)+len(daemonSetScaleDownNodeSelector))
- for k, v := range dae.Spec.Template.Spec.NodeSelector {
- daeCopy.Spec.Template.Spec.NodeSelector[k] = v
+ patch, err := c.getNodeSelectorPatch(daemonSetScaleDownNodeSelector)
+ if err == nil {
+ _, err = c.kubeClient.AppsV1().DaemonSets(dae.Namespace).Patch(context.TODO(), dae.GetName(), types.StrategicMergePatchType, patch, metav1.PatchOptions{})
  }
 
- for k, v := range daemonSetScaleDownNodeSelector {
- daeCopy.Spec.Template.Spec.NodeSelector[k] = v
- }
-
- _, err = c.kubeClient.AppsV1().DaemonSets(dae.Namespace).Update(context.TODO(), daeCopy, metav1.UpdateOptions{})
  if err != nil {
- return fmt.Errorf("updating daemonset %s.%s failed: %w", daeCopy.GetName(), daeCopy.Namespace, err)
+ return fmt.Errorf("updating daemonset %s.%s failed: %w", dae.GetName(), dae.Namespace, err)
  }
  return nil
 }
 
 func (c *DaemonSetController) ScaleFromZero(cd *flaggerv1.Canary) error {
  targetName := cd.Spec.TargetRef.Name
- dep, err := c.kubeClient.AppsV1().DaemonSets(cd.Namespace).Get(context.TODO(), targetName, metav1.GetOptions{})
+ dae, err := c.kubeClient.AppsV1().DaemonSets(cd.Namespace).Get(context.TODO(), targetName, metav1.GetOptions{})
  if err != nil {
  return fmt.Errorf("daemonset %s.%s query error: %w", targetName, cd.Namespace, err)
  }
 
- depCopy := dep.DeepCopy()
+ nodeSelector := map[string]interface{}{}
  for k := range daemonSetScaleDownNodeSelector {
- delete(depCopy.Spec.Template.Spec.NodeSelector, k)
+ nodeSelector[k] = nil
+ }
+ patch, err := c.getNodeSelectorPatch(nodeSelector)
+ if err == nil {
+ _, err = c.kubeClient.AppsV1().DaemonSets(dae.Namespace).Patch(context.TODO(), dae.GetName(), types.StrategicMergePatchType, patch, metav1.PatchOptions{})
  }
 
- _, err = c.kubeClient.AppsV1().DaemonSets(dep.Namespace).Update(context.TODO(), depCopy, metav1.UpdateOptions{})
  if err != nil {
- return fmt.Errorf("scaling up daemonset %s.%s failed: %w", depCopy.GetName(), depCopy.Namespace, err)
+ return fmt.Errorf("scaling up daemonset %s.%s failed: %w", dae.GetName(), dae.Namespace, err)
  }
  return nil
 }
@@ -324,6 +322,16 @@ func (c *DaemonSetController) getSelectorLabel(daemonSet *appsv1.DaemonSet) (str
  )
 }
 
+// createNodeSelectorPatch returns the nodeSelector field strategic patch used for scaling
+func (c *DaemonSetController) getNodeSelectorPatch(nodeSelector map[string]interface{}) ([]byte, error) {
+ nodeSelectorJSON, err := json.Marshal(nodeSelector)
+ if err != nil {
+ return nil, err
+ }
+ patch := []byte(fmt.Sprintf(`{"spec":{"template":{"spec":{"nodeSelector":%s}}}}`, nodeSelectorJSON))
+ return patch, nil
+}
+
 func (c *DaemonSetController) HaveDependenciesChanged(cd *flaggerv1.Canary) (bool, error) {
  return c.configTracker.HasConfigChanged(cd)
 }