Small refactoring around drain - move drain logic to separate function.

pkg/kubectl/cmd/drain.go

@@ -183,7 +183,7 @@ func (o *DrainOptions) RunDrain() error {
 		return err
 	}
 
-	pods, err := o.GetPodsForDeletion()
+	pods, err := o.getPodsForDeletion()
 	if err != nil {
 		return err
 	}
@@ -195,17 +195,55 @@ func (o *DrainOptions) RunDrain() error {
 	return nil
 }
 
-// GetPodsForDeletion returns all the pods we're going to delete.  If there are
+// getPodsForDeletion returns all the pods we're going to delete.  If there are
 // any unmanaged pods and the user didn't pass --force, we return that list in
 // an error.
-func (o *DrainOptions) GetPodsForDeletion() ([]api.Pod, error) {
-	pods := []api.Pod{}
-	podList, err := o.client.Pods(api.NamespaceAll).List(api.ListOptions{FieldSelector: fields.SelectorFromSet(fields.Set{"spec.nodeName": o.nodeInfo.Name})})
+func (o *DrainOptions) getPodsForDeletion() ([]api.Pod, error) {
+	pods, unreplicatedPodNames, daemonSetPodNames, err := GetPodsForDeletionOnNodeDrain(
+		o.client,
+		o.nodeInfo.Name,
+		o.factory.Decoder(true),
+		o.Force,
+		o.IgnoreDaemonsets,
+	)
 	if err != nil {
-		return pods, err
+		return []api.Pod{}, err
+	}
+
+	daemonSetErrors := !o.IgnoreDaemonsets && len(daemonSetPodNames) > 0
+	unreplicatedErrors := !o.Force && len(unreplicatedPodNames) > 0
+
+	switch {
+	case daemonSetErrors && unreplicatedErrors:
+		return []api.Pod{}, errors.New(unmanagedMsg(unreplicatedPodNames, daemonSetPodNames, true))
+	case daemonSetErrors && !unreplicatedErrors:
+		return []api.Pod{}, errors.New(unmanagedMsg([]string{}, daemonSetPodNames, true))
+	case unreplicatedErrors && !daemonSetErrors:
+		return []api.Pod{}, errors.New(unmanagedMsg(unreplicatedPodNames, []string{}, true))
+	}
+
+	if len(unreplicatedPodNames) > 0 {
+		fmt.Fprintf(o.out, "WARNING: About to delete these %s\n", unmanagedMsg(unreplicatedPodNames, []string{}, false))
+	}
+	if len(daemonSetPodNames) > 0 {
+		fmt.Fprintf(o.out, "WARNING: Skipping %s\n", unmanagedMsg([]string{}, daemonSetPodNames, false))
+	}
+
+	return pods, nil
+}
+
+// GetPodsForDeletionOnNodeDrain returns pods that should be deleted on node drain as well as some extra information
+// about possibly problematic pods (unreplicated and deamon sets).
+func GetPodsForDeletionOnNodeDrain(client *client.Client, nodename string, decoder runtime.Decoder, force bool,
+	ignoreDeamonSet bool) (pods []api.Pod, unreplicatedPodNames []string, daemonSetPodNames []string, finalError error) {
+
+	pods = []api.Pod{}
+	unreplicatedPodNames = []string{}
+	daemonSetPodNames = []string{}
+	podList, err := client.Pods(api.NamespaceAll).List(api.ListOptions{FieldSelector: fields.SelectorFromSet(fields.Set{"spec.nodeName": nodename})})
+	if err != nil {
+		return []api.Pod{}, []string{}, []string{}, err
 	}
-	unreplicatedPodNames := []string{}
-	daemonSetPodNames := []string{}
 
 	for _, pod := range podList.Items {
 		_, found := pod.ObjectMeta.Annotations[types.ConfigMirrorAnnotationKey]
@@ -220,11 +258,11 @@ func (o *DrainOptions) GetPodsForDeletion() ([]api.Pod, error) {
 		if found {
 			// Now verify that the specified creator actually exists.
 			var sr api.SerializedReference
-			if err := runtime.DecodeInto(o.factory.Decoder(true), []byte(creatorRef), &sr); err != nil {
-				return pods, err
+			if err := runtime.DecodeInto(decoder, []byte(creatorRef), &sr); err != nil {
+				return []api.Pod{}, []string{}, []string{}, err
 			}
 			if sr.Reference.Kind == "ReplicationController" {
-				rc, err := o.client.ReplicationControllers(sr.Reference.Namespace).Get(sr.Reference.Name)
+				rc, err := client.ReplicationControllers(sr.Reference.Namespace).Get(sr.Reference.Name)
 				// Assume the only reason for an error is because the RC is
 				// gone/missing, not for any other cause.  TODO(mml): something more
 				// sophisticated than this
@@ -232,7 +270,7 @@ func (o *DrainOptions) GetPodsForDeletion() ([]api.Pod, error) {
 					replicated = true
 				}
 			} else if sr.Reference.Kind == "DaemonSet" {
-				ds, err := o.client.DaemonSets(sr.Reference.Namespace).Get(sr.Reference.Name)
+				ds, err := client.DaemonSets(sr.Reference.Namespace).Get(sr.Reference.Name)
 
 				// Assume the only reason for an error is because the DaemonSet is
 				// gone/missing, not for any other cause.  TODO(mml): something more
@@ -245,7 +283,7 @@ func (o *DrainOptions) GetPodsForDeletion() ([]api.Pod, error) {
 					daemonset_pod = true
 				}
 			} else if sr.Reference.Kind == "Job" {
-				job, err := o.client.ExtensionsClient.Jobs(sr.Reference.Namespace).Get(sr.Reference.Name)
+				job, err := client.ExtensionsClient.Jobs(sr.Reference.Namespace).Get(sr.Reference.Name)
 
 				// Assume the only reason for an error is because the Job is
 				// gone/missing, not for any other cause.  TODO(mml): something more
@@ -254,7 +292,7 @@ func (o *DrainOptions) GetPodsForDeletion() ([]api.Pod, error) {
 					replicated = true
 				}
 			} else if sr.Reference.Kind == "ReplicaSet" {
-				rs, err := o.client.ExtensionsClient.ReplicaSets(sr.Reference.Namespace).Get(sr.Reference.Name)
+				rs, err := client.ExtensionsClient.ReplicaSets(sr.Reference.Namespace).Get(sr.Reference.Name)
 
 				// Assume the only reason for an error is because the RS is
 				// gone/missing, not for any other cause.  TODO(mml): something more
@@ -270,34 +308,14 @@ func (o *DrainOptions) GetPodsForDeletion() ([]api.Pod, error) {
 			daemonSetPodNames = append(daemonSetPodNames, pod.Name)
 		case !replicated:
 			unreplicatedPodNames = append(unreplicatedPodNames, pod.Name)
-			if o.Force {
+			if force {
 				pods = append(pods, pod)
 			}
 		default:
 			pods = append(pods, pod)
 		}
 	}
-
-	daemonSetErrors := !o.IgnoreDaemonsets && len(daemonSetPodNames) > 0
-	unreplicatedErrors := !o.Force && len(unreplicatedPodNames) > 0
-
-	switch {
-	case daemonSetErrors && unreplicatedErrors:
-		return []api.Pod{}, errors.New(unmanagedMsg(unreplicatedPodNames, daemonSetPodNames, true))
-	case daemonSetErrors && !unreplicatedErrors:
-		return []api.Pod{}, errors.New(unmanagedMsg([]string{}, daemonSetPodNames, true))
-	case unreplicatedErrors && !daemonSetErrors:
-		return []api.Pod{}, errors.New(unmanagedMsg(unreplicatedPodNames, []string{}, true))
-	}
-
-	if len(unreplicatedPodNames) > 0 {
-		fmt.Fprintf(o.out, "WARNING: About to delete these %s\n", unmanagedMsg(unreplicatedPodNames, []string{}, false))
-	}
-	if len(daemonSetPodNames) > 0 {
-		fmt.Fprintf(o.out, "WARNING: Skipping %s\n", unmanagedMsg([]string{}, daemonSetPodNames, false))
-	}
-
-	return pods, nil
+	return pods, unreplicatedPodNames, daemonSetPodNames, nil
 }
 
 // Helper for generating errors or warnings about unmanaged pods.