Merge pull request #65837 from clandry94/pvc_describe_claimed_by

Automatic merge from submit-queue (batch tested with PRs 65838, 65837). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>. output which pods are a pvc in use when kubectl describe pvc is run **What this PR does / why we need it**: This PR implements a feature request to display the pods mounted to a PVC when `kubectl describe pvc` is ran. We need it since the only way to see which pods are bound to a PVC is by checking the volume mounts of each individual pod in the namespace. Example Output: ``` $ kubectl get pods,pvc NAME READY STATUS RESTARTS AGE test-pod 1/1 Running 0 2h NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE test-pvc Bound pvc-718681dd-70cc-11e7-aa14-42010af00029 100Gi RWO us-east1-b 345d ``` ``` $ kubectl describe pvc Name: elasticsearch-data-elasticsearch-data-us-east1-b-0 Namespace: partners-production StorageClass: us-east1-b Status: Bound Volume: pvc-718681dd-70cc-11e7-aa14-42010af00029 Labels: <none> Annotations: <none> Finalizers: [kubernetes.io/pvc-protection] Capacity: 1Gi Access Modes: RWO Events: <none> Mounted By: test-pod ``` Pods using the PVC are shown with the `Mounted By` field **Which issue(s) this PR fixes**: Closes #65233 **Special notes for your reviewer**: **Release note**: ```release-note Running `kubectl describe pvc` now shows which pods are mounted to the pvc being described with the `Mounted By` field ```

Merge pull request #65837 from clandry94/pvc_describe_claimed_by
54db2273 · Kubernetes Submit Queue · GitHub · b6c52143 · d9569948 · 54db2273
Unverified Commit 54db2273 authored Jul 06, 2018 by Kubernetes Submit Queue Committed by GitHub Jul 06, 2018
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Showing with 75 additions and 2 deletions

describe.go pkg/printers/internalversion/describe.go +75 -2

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--- a/pkg/printers/internalversion/describe.go
+++ b/pkg/printers/internalversion/describe.go
@@ -1291,12 +1291,52 @@ func (d *PersistentVolumeClaimDescriber) Describe(namespace, name string, descri
 		return "", err
 	}

+	pc := d.Core().Pods(namespace)
+
+	mountPods, err := getMountPods(pc, pvc.Name)
+	if err != nil {
+		return "", err
+	}
+
 	events, _ := d.Core().Events(namespace).Search(legacyscheme.Scheme, pvc)

-	return describePersistentVolumeClaim(pvc, events)
+	return describePersistentVolumeClaim(pvc, events, mountPods)
+}
+
+func getMountPods(c coreclient.PodInterface, pvcName string) ([]api.Pod, error) {
+	nsPods, err := c.List(metav1.ListOptions{})
+	if err != nil {
+		return []api.Pod{}, err
+	}
+
+	var pods []api.Pod
+
+	for _, pod := range nsPods.Items {
+		pvcs := getPvcs(pod.Spec.Volumes)
+
+		for _, pvc := range pvcs {
+			if pvc.PersistentVolumeClaim.ClaimName == pvcName {
+				pods = append(pods, pod)
+			}
+		}
+	}
+
+	return pods, nil
 }

-func describePersistentVolumeClaim(pvc *api.PersistentVolumeClaim, events *api.EventList) (string, error) {
+func getPvcs(volumes []api.Volume) []api.Volume {
+	var pvcs []api.Volume
+
+	for _, volume := range volumes {
+		if volume.VolumeSource.PersistentVolumeClaim != nil {
+			pvcs = append(pvcs, volume)
+		}
+	}
+
+	return pvcs
+}
+
+func describePersistentVolumeClaim(pvc *api.PersistentVolumeClaim, events *api.EventList, mountPods []api.Pod) (string, error) {
 	return tabbedString(func(out io.Writer) error {
 		w := NewPrefixWriter(out)
 		w.Write(LEVEL_0, "Name:\t%s\n", pvc.Name)
@@ -1342,6 +1382,8 @@ func describePersistentVolumeClaim(pvc *api.PersistentVolumeClaim, events *api.E
 			DescribeEvents(events, w)
 		}

+		printPodsMultiline(w, "Mounted By", mountPods)
+
 		return nil
 	})
 }
@@ -3867,6 +3909,37 @@ func printTaintsMultilineWithIndent(w PrefixWriter, initialIndent, title, innerI
 	}
 }

+// printPodsMultiline prints multiple pods with a proper alignment.
+func printPodsMultiline(w PrefixWriter, title string, pods []api.Pod) {
+	printPodsMultilineWithIndent(w, "", title, "\t", pods)
+}
+
+// printPodsMultilineWithIndent prints multiple pods with a user-defined alignment.
+func printPodsMultilineWithIndent(w PrefixWriter, initialIndent, title, innerIndent string, pods []api.Pod) {
+	w.Write(LEVEL_0, "%s%s:%s", initialIndent, title, innerIndent)
+
+	if pods == nil || len(pods) == 0 {
+		w.WriteLine("<none>")
+		return
+	}
+
+	// to print pods in the sorted order
+	sort.Slice(pods, func(i, j int) bool {
+		cmpKey := func(pod api.Pod) string {
+			return pod.Name
+		}
+		return cmpKey(pods[i]) < cmpKey(pods[j])
+	})
+
+	for i, pod := range pods {
+		if i != 0 {
+			w.Write(LEVEL_0, "%s", initialIndent)
+			w.Write(LEVEL_0, "%s", innerIndent)
+		}
+		w.Write(LEVEL_0, "%s\n", pod.Name)
+	}
+}
+
 // printPodTolerationsMultiline prints multiple tolerations with a proper alignment.
 func printPodTolerationsMultiline(w PrefixWriter, title string, tolerations []api.Toleration) {
 	printTolerationsMultilineWithIndent(w, "", title, "\t", tolerations)