UPSTREAM: <carry>: add machine api label and taint functionality

This change re-adds the machine api support for labels and taints on
node groups. The code was removed upstream as it is openshift specific,
see this pull request[0].

[0]: kubernetes#5249

cluster-autoscaler/cloudprovider/clusterapi/clusterapi_nodegroup_test.go

@@ -1297,6 +1297,7 @@ func TestNodeGroupTemplateNodeInfo(t *testing.T) {
 
 	type testCaseConfig struct {
 		nodeLabels         map[string]string
+		nodegroupLabels    map[string]string
 		includeNodes       bool
 		expectedErr        error
 		expectedCapacity   map[corev1.ResourceName]int64
@@ -1359,10 +1360,11 @@ func TestNodeGroupTemplateNodeInfo(t *testing.T) {
 					gpuapis.ResourceNvidiaGPU: 1,
 				},
 				expectedNodeLabels: map[string]string{
-					"kubernetes.io/os":       "linux",
-					"kubernetes.io/arch":     "arm64",
 					"kubernetes.io/hostname": "random value",
-					"my-custom-label":        "custom-value",
+					"kubernetes.io/os":       "linux",
+					"kubernetes.io/arch":     "amd64",
+					"nodeGroupLabel":         "value",
+					"anotherLabel":           "anotherValue",
 				},
 			},
 		},
@@ -1396,6 +1398,12 @@ func TestNodeGroupTemplateNodeInfo(t *testing.T) {
 	}
 
 	test := func(t *testing.T, testConfig *testConfig, config testCaseConfig) {
+		if testConfig.machineDeployment != nil {
+			unstructured.SetNestedStringMap(testConfig.machineDeployment.Object, config.nodegroupLabels, "spec", "template", "spec", "metadata", "labels")
+		} else {
+			unstructured.SetNestedStringMap(testConfig.machineSet.Object, config.nodegroupLabels, "spec", "template", "spec", "metadata", "labels")
+		}
+
 		if config.includeNodes {
 			for i := range testConfig.nodes {
 				testConfig.nodes[i].SetLabels(config.nodeLabels)

cluster-autoscaler/cloudprovider/clusterapi/clusterapi_unstructured.go

@@ -174,37 +174,28 @@ func (r unstructuredScalableResource) MarkMachineForDeletion(machine *unstructur
 }
 
 func (r unstructuredScalableResource) Labels() map[string]string {
-	annotations := r.unstructured.GetAnnotations()
-	// annotation value of the form "key1=value1,key2=value2"
-	if val, found := annotations[labelsKey]; found {
-		labels := strings.Split(val, ",")
-		kv := make(map[string]string, len(labels))
-		for _, label := range labels {
-			split := strings.SplitN(label, "=", 2)
-			if len(split) == 2 {
-				kv[split[0]] = split[1]
-			}
-		}
-		return kv
+	labels, found, err := unstructured.NestedStringMap(r.unstructured.Object, "spec", "template", "spec", "metadata", "labels")
+	if !found || err != nil {
+		return nil
 	}
-	return nil
+	return labels
 }
 
 func (r unstructuredScalableResource) Taints() []apiv1.Taint {
-	annotations := r.unstructured.GetAnnotations()
-	// annotation value the form of "key1=value1:condition,key2=value2:condition"
-	if val, found := annotations[taintsKey]; found {
-		taints := strings.Split(val, ",")
-		ret := make([]apiv1.Taint, 0, len(taints))
-		for _, taintStr := range taints {
-			taint, err := parseTaint(taintStr)
-			if err == nil {
-				ret = append(ret, taint)
-			}
+	taints, found, err := unstructured.NestedSlice(r.unstructured.Object, "spec", "template", "spec", "taints")
+	if !found || err != nil {
+		return nil
+	}
+	ret := make([]apiv1.Taint, len(taints))
+	for i, t := range taints {
+		if v, ok := t.(apiv1.Taint); ok {
+			ret[i] = v
+		} else {
+			// if we cannot convert the interface to a Taint, return early with zero value
+			return nil
 		}
-		return ret
 	}
-	return nil
+	return ret
 }
 
 // A node group can scale from zero if it can inform about the CPU and memory