Add Snapshot() method to the NodeDeletionTracker

cluster-autoscaler/core/scaledown/actuation/actuator.go

@@ -66,12 +66,9 @@ func NewActuator(ctx *context.AutoscalingContext, csr *clusterstate.ClusterState
 	}
 }
 
-// CheckStatus should return an immutable snapshot of ongoing deletions. Before the TODO is addressed, a live object
-// is returned instead of an immutable snapshot.
+// CheckStatus should returns an immutable snapshot of ongoing deletions.
 func (a *Actuator) CheckStatus() scaledown.ActuationStatus {
-	// TODO: snapshot information from the tracker instead of keeping live
-	// updated object.
-	return a.nodeDeletionTracker
+	return a.nodeDeletionTracker.Snapshot()
 }
 
 // ClearResultsNotNewerThan removes information about deletions finished before or exactly at the provided timestamp.

cluster-autoscaler/core/scaledown/deletiontracker/nodedeletiontracker.go

@@ -168,3 +168,26 @@ func (n *NodeDeletionTracker) ClearResultsNotNewerThan(t time.Time) {
 	defer n.Unlock()
 	n.deletionResults.DropNotNewerThan(t)
 }
+
+// Snapshot return a copy of NodeDeletionTracker.
+func (n *NodeDeletionTracker) Snapshot() *NodeDeletionTracker {
+	n.Lock()
+	defer n.Unlock()
+	snapshot := NewNodeDeletionTracker(n.evictionsTTL)
+	for k, val := range n.emptyNodeDeletions {
+		snapshot.emptyNodeDeletions[k] = val
+	}
+	for k, val := range n.drainedNodeDeletions {
+		snapshot.drainedNodeDeletions[k] = val
+	}
+	for k, val := range n.deletionsPerNodeGroup {
+		snapshot.deletionsPerNodeGroup[k] = val
+	}
+	for _, eviction := range n.evictions.ToSlice() {
+		snapshot.evictions.RegisterElement(eviction)
+	}
+	for _, result := range n.deletionResults.ToSlice() {
+		snapshot.deletionResults.RegisterElement(result)
+	}
+	return snapshot
+}

cluster-autoscaler/core/scaledown/scaledown.go

@@ -65,6 +65,7 @@ type Actuator interface {
 }
 
 // ActuationStatus is used for feeding Actuator status back into Planner
+// TODO: Replace ActuationStatus with simple struct with getter methods.
 type ActuationStatus interface {
 	// DeletionsInProgress returns two lists of node names that are
 	// currently undergoing deletion, for empty and non-empty (i.e. drained)
@@ -77,10 +78,4 @@ type ActuationStatus interface {
 	// the Actuator and hence are likely to get recreated elsewhere in the
 	// cluster.
 	RecentEvictions() (pods []*apiv1.Pod)
-	// DeletionResults returns a map of recent node deletion results, keyed
-	// by the node name. Note: if node deletion was scheduled more than
-	// once, only the latest result will be present.
-	// The timestamp returned as the second value indicates the time at
-	// which the last result was collected.
-	DeletionResults() (map[string]status.NodeDeleteResult, time.Time)
 }