Merge pull request #42913 from aveshagarwal/master-fix-taint-based-eviction-no-node-cidr

Automatic merge from submit-queue

Fix taint based pod eviction for clusters where controller manager is not running with allocate-node-cidrs set

Fixes https://github.com/kubernetes/kubernetes/issues/42733

In my cluster, I have not set allocate-node-cidr, and It is causing taint based pod eviction to fail. 

@gmarek @kubernetes/sig-scheduling-bugs @davidopp @derekwaynecarr

pkg/controller/node/nodecontroller.go

@@ -415,6 +415,53 @@ func NewNodeController(
 				}
 			},
 		}
+	} else {
+		nodeEventHandlerFuncs = cache.ResourceEventHandlerFuncs{
+			AddFunc: func(originalObj interface{}) {
+				obj, err := api.Scheme.DeepCopy(originalObj)
+				if err != nil {
+					utilruntime.HandleError(err)
+					return
+				}
+				node := obj.(*v1.Node)
+				if nc.taintManager != nil {
+					nc.taintManager.NodeUpdated(nil, node)
+				}
+			},
+			UpdateFunc: func(oldNode, newNode interface{}) {
+				node := newNode.(*v1.Node)
+				prevNode := oldNode.(*v1.Node)
+				if nc.taintManager != nil {
+					nc.taintManager.NodeUpdated(prevNode, node)
+
+				}
+			},
+			DeleteFunc: func(originalObj interface{}) {
+				obj, err := api.Scheme.DeepCopy(originalObj)
+				if err != nil {
+					utilruntime.HandleError(err)
+					return
+				}
+
+				node, isNode := obj.(*v1.Node)
+				// We can get DeletedFinalStateUnknown instead of *v1.Node here and we need to handle that correctly. #34692
+				if !isNode {
+					deletedState, ok := obj.(cache.DeletedFinalStateUnknown)
+					if !ok {
+						glog.Errorf("Received unexpected object: %v", obj)
+						return
+					}
+					node, ok = deletedState.Obj.(*v1.Node)
+					if !ok {
+						glog.Errorf("DeletedFinalStateUnknown contained non-Node object: %v", deletedState.Obj)
+						return
+					}
+				}
+				if nc.taintManager != nil {
+					nc.taintManager.NodeUpdated(node, nil)
+				}
+			},
+		}
 	}
 
 	if nc.runTaintManager {