node labels and taints do not change, node events are ignored in daemonset controller

Signed-off-by: xigang <wangxigang2014@gmail.com>

pkg/controller/daemon/daemon_controller_test.go

@@ -3580,3 +3580,43 @@ func TestStoreDaemonSetStatus(t *testing.T) {
 		})
 	}
 }
+
+func TestShouldIgnoreNodeUpdate(t *testing.T) {
+	cases := []struct {
+		name           string
+		newNode        *v1.Node
+		oldNode        *v1.Node
+		expectedResult bool
+	}{
+		{
+			name:           "Nothing changed",
+			oldNode:        newNode("node1", nil),
+			newNode:        newNode("node1", nil),
+			expectedResult: true,
+		},
+		{
+			name:           "Node labels changed",
+			oldNode:        newNode("node1", nil),
+			newNode:        newNode("node1", simpleNodeLabel),
+			expectedResult: false,
+		},
+		{
+			name: "Node taints changed",
+			oldNode: func() *v1.Node {
+				node := newNode("node1", nil)
+				setNodeTaint(node, noScheduleTaints)
+				return node
+			}(),
+			newNode:        newNode("node1", nil),
+			expectedResult: false,
+		},
+	}
+
+	for _, c := range cases {
+		result := shouldIgnoreNodeUpdate(*c.oldNode, *c.newNode)
+
+		if result != c.expectedResult {
+			t.Errorf("[%s] unexpected results: %v", c.name, result)
+		}
+	}
+}