Reintroduce snapshot state 'Populated' (#830)

The snapshot state 'Populated' was replaced with 'Ready' in commit
`1f839f4`. However, logic to handle old snapshots still in state
'Populated' was left out.

This commit adds the state 'Populated' back and adds logic to transfer
snapshots in state 'Populated' to 'Ready'.

Author: gonzolino

api/snapshot.go

@@ -18,9 +18,10 @@ type Snapshot struct {
 type SnapshotState string
 
 const (
-	SnapshotStatePending SnapshotState = "Pending"
-	SnapshotStateReady   SnapshotState = "Ready"
-	SnapshotStateFailed  SnapshotState = "Failed"
+	SnapshotStatePending   SnapshotState = "Pending"
+	SnapshotStatePopulated SnapshotState = "Populated"
+	SnapshotStateReady     SnapshotState = "Ready"
+	SnapshotStateFailed    SnapshotState = "Failed"
 )
 
 type SnapshotStatus struct {

internal/controllers/image_controller.go

@@ -746,7 +746,7 @@ func (r *ImageReconciler) createImageFromSnapshot(ctx context.Context, log logr.
 		return false, nil
 	}
 
-	if snapshot.Status.State != providerapi.SnapshotStateReady {
+	if snapshot.Status.State != providerapi.SnapshotStateReady && snapshot.Status.State != providerapi.SnapshotStatePopulated {
 		log.V(1).Info("snapshot is not populated", "state", snapshot.Status.State)
 		return false, nil
 	}

internal/controllers/snapshot_controller.go

@@ -249,8 +249,20 @@ func (r *SnapshotReconciler) reconcileSnapshot(ctx context.Context, id string) e
 		return nil
 	}
 
-	if snapshot.Status.State == providerapi.SnapshotStateReady {
+	// SnapshotStatePopulated is no longer actively used. It has been replaced by SnapshotStateReady.
+	// This block will transition any snapshots that are in SnapshotStatePopulated to SnapshotStateReady.
+	if snapshot.Status.State == providerapi.SnapshotStatePopulated {
 		log.V(1).Info("Snapshot already populated")
+		snapshot.Status.State = providerapi.SnapshotStateReady
+		if _, err = r.store.Update(ctx, snapshot); err != nil {
+			return fmt.Errorf("failed to update snapshot: %w", err)
+		}
+
+		return nil
+	}
+
+	if snapshot.Status.State == providerapi.SnapshotStateReady {
+		log.V(1).Info("Snapshot is ready")
 		return nil
 	}