Merge pull request kubernetes#42992 from NickrenREN/syncUnboundClaim

Automatic merge from submit-queue (batch tested with PRs 43453, 42992)

make sure that the volume satisfies the requirements of the claim before binding

check if the volume requested by the claim satisfies the requirements of the claim before binding when
syncUnboundClaim and claim.Spec.VolumeName is not set, although the volume is asked by user


**Release note**:
```release-note
NONE
```

pkg/controller/volume/persistentvolume/binder_test.go

@@ -254,12 +254,33 @@ func TestSync(t *testing.T) {
 			// unbound, but does not match the selector. Check it gets bound
 			// and no annBoundByController is set.
 			"2-8 - claim prebound to unbound volume that does not match the selector",
-			newVolumeArray("volume2-3", "1Gi", "", "", v1.VolumePending, v1.PersistentVolumeReclaimRetain, classEmpty),
-			newVolumeArray("volume2-3", "1Gi", "uid2-3", "claim2-3", v1.VolumeBound, v1.PersistentVolumeReclaimRetain, classEmpty, annBoundByController),
-			withLabelSelector(labels, newClaimArray("claim2-3", "uid2-3", "1Gi", "volume2-3", v1.ClaimPending, nil)),
-			withLabelSelector(labels, newClaimArray("claim2-3", "uid2-3", "1Gi", "volume2-3", v1.ClaimBound, nil, annBindCompleted)),
+			newVolumeArray("volume2-8", "1Gi", "", "", v1.VolumePending, v1.PersistentVolumeReclaimRetain, classEmpty),
+			newVolumeArray("volume2-8", "1Gi", "uid2-8", "claim2-8", v1.VolumeBound, v1.PersistentVolumeReclaimRetain, classEmpty, annBoundByController),
+			withLabelSelector(labels, newClaimArray("claim2-8", "uid2-8", "1Gi", "volume2-8", v1.ClaimPending, nil)),
+			withLabelSelector(labels, newClaimArray("claim2-8", "uid2-8", "1Gi", "volume2-8", v1.ClaimBound, nil, annBindCompleted)),
 			noevents, noerrors, testSyncClaim,
 		},
+		{
+			// syncClaim with claim pre-bound to a PV that exists and is
+			// unbound, but its size is smaller than requested.
+			//Check that the claim status is reset to Pending
+			"2-9 - claim prebound to unbound volume that size is smaller than requested",
+			newVolumeArray("volume2-9", "1Gi", "", "", v1.VolumePending, v1.PersistentVolumeReclaimRetain, classEmpty),
+			newVolumeArray("volume2-9", "1Gi", "", "", v1.VolumePending, v1.PersistentVolumeReclaimRetain, classEmpty),
+			newClaimArray("claim2-9", "uid2-9", "2Gi", "volume2-9", v1.ClaimBound, nil),
+			newClaimArray("claim2-9", "uid2-9", "2Gi", "volume2-9", v1.ClaimPending, nil),
+			[]string{"Warning VolumeMismatch"}, noerrors, testSyncClaim,
+		},
+		{
+			// syncClaim with claim pre-bound to a PV that exists and is
+			// unbound, but its class does not match. Check that the claim status is reset to Pending
+			"2-10 - claim prebound to unbound volume that class is different",
+			newVolumeArray("volume2-10", "1Gi", "1", "", v1.VolumePending, v1.PersistentVolumeReclaimRetain, classGold),
+			newVolumeArray("volume2-10", "1Gi", "", "", v1.VolumePending, v1.PersistentVolumeReclaimRetain, classGold),
+			newClaimArray("claim2-10", "uid2-10", "1Gi", "volume2-10", v1.ClaimBound, nil),
+			newClaimArray("claim2-10", "uid2-10", "1Gi", "volume2-10", v1.ClaimPending, nil),
+			[]string{"Warning VolumeMismatch"}, noerrors, testSyncClaim,
+		},
 
 		// [Unit test set 3] Syncing bound claim
 		{

pkg/controller/volume/persistentvolume/pv_controller.go

@@ -225,6 +225,25 @@ func (ctrl *PersistentVolumeController) syncClaim(claim *v1.PersistentVolumeClai
 	}
 }
 
+//checkVolumeSatisfyClaim checks if the volume requested by the claim satisfies the requirements of the claim
+func checkVolumeSatisfyClaim(volume *v1.PersistentVolume, claim *v1.PersistentVolumeClaim) error {
+	requestedQty := claim.Spec.Resources.Requests[v1.ResourceName(v1.ResourceStorage)]
+	requestedSize := requestedQty.Value()
+
+	volumeQty := volume.Spec.Capacity[v1.ResourceStorage]
+	volumeSize := volumeQty.Value()
+	if volumeSize < requestedSize {
+		return fmt.Errorf("Storage capacity of volume[%s] requested by claim[%v] is not enough", volume.Name, claimToClaimKey(claim))
+	}
+
+	requestedClass := v1.GetPersistentVolumeClaimClass(claim)
+	if v1.GetPersistentVolumeClass(volume) != requestedClass {
+		return fmt.Errorf("Class of volume[%s] is not the same as claim[%v]", volume.Name, claimToClaimKey(claim))
+	}
+
+	return nil
+}
+
 // syncUnboundClaim is the main controller method to decide what to do with an
 // unbound claim.
 func (ctrl *PersistentVolumeController) syncUnboundClaim(claim *v1.PersistentVolumeClaim) error {
@@ -295,7 +314,15 @@ func (ctrl *PersistentVolumeController) syncUnboundClaim(claim *v1.PersistentVol
 				// User asked for a PV that is not claimed
 				// OBSERVATION: pvc is "Pending", pv is "Available"
 				glog.V(4).Infof("synchronizing unbound PersistentVolumeClaim[%s]: volume is unbound, binding", claimToClaimKey(claim))
-				if err = ctrl.bind(volume, claim); err != nil {
+				if err = checkVolumeSatisfyClaim(volume, claim); err != nil {
+					glog.V(4).Infof("Can't bind the claim to volume %q: %v", volume.Name, err)
+					//send a event
+					ctrl.eventRecorder.Event(volume, v1.EventTypeWarning, "VolumeMismatch", "Volume's size is smaller than requested or volume's class does not match with claim")
+					//volume does not satisfy the requirements of the claim
+					if _, err = ctrl.updateClaimStatus(claim, v1.ClaimPending, nil); err != nil {
+						return err
+					}
+				} else if err = ctrl.bind(volume, claim); err != nil {
 					// On any error saving the volume or the claim, subsequent
 					// syncClaim will finish the binding.
 					return err