func main()

in hack/tools/allocatable_diff/main.go [52:121]
61 lines of code
5 McCabe index (conditional complexity)

func main() {
	if clusterName == "" {
		log.Fatalf("cluster name cannot be empty")
	}
	restConfig := config.GetConfigOrDie()
	kubeClient := lo.Must(client.New(restConfig, client.Options{}))
	ctx := context.Background()
	ctx = options.ToContext(ctx, &options.Options{ClusterName: clusterName, IsolatedVPC: true, VMMemoryOverheadPercent: overheadPercent})

	file := lo.Must(os.OpenFile(outFile, os.O_RDWR|os.O_CREATE, 0777))
	defer file.Close()

	w := csv.NewWriter(file)
	defer w.Flush()

	nodeList := &v1.NodeList{}
	lo.Must0(kubeClient.List(ctx, nodeList))

	ctx, op := operator.NewOperator(ctx, &coreoperator.Operator{
		Manager:             lo.Must(manager.New(restConfig, manager.Options{})),
		KubernetesInterface: kubernetes.NewForConfigOrDie(restConfig),
	})
	cloudProvider := cloudprovider.New(
		op.InstanceTypesProvider,
		op.InstanceProvider,
		op.EventRecorder,
		op.GetClient(),
		op.AMIProvider,
		op.SecurityGroupProvider,
		op.CapacityReservationProvider,
	)
	instanceTypes := lo.Must(cloudProvider.GetInstanceTypes(ctx, nil))

	// Write the header information into the CSV
	lo.Must0(w.Write([]string{"Instance Type", "Expected Capacity", "", "", "Expected Allocatable", "", "", "Actual Capacity", "", "", "Actual Allocatable", ""}))
	lo.Must0(w.Write([]string{"", "Memory (Mi)", "CPU (m)", "Storage (Mi)", "Memory (Mi)", "CPU (m)", "Storage (Mi)", "Memory (Mi)", "CPU (m)", "Storage (Mi)", "Memory (Mi)", "CPU (m)", "Storage (Mi)"}))

	nodeList.Items = lo.Filter(nodeList.Items, func(n v1.Node, _ int) bool {
		return n.Labels["karpenter.sh/provisioner-name"] != "" && n.Status.Allocatable.Memory().Value() != 0
	})
	sort.Slice(nodeList.Items, func(i, j int) bool {
		return nodeList.Items[i].Labels[v1.LabelInstanceTypeStable] < nodeList.Items[j].Labels[v1.LabelInstanceTypeStable]
	})
	for _, node := range nodeList.Items {
		instanceType, ok := lo.Find(instanceTypes, func(i *corecloudprovider.InstanceType) bool {
			return i.Name == node.Labels[v1.LabelInstanceTypeStable]
		})
		if !ok {
			log.Fatalf("retrieving instance type for instance %s", node.Labels[v1.LabelInstanceTypeStable])
		}
		allocatable := instanceType.Allocatable()

		// Write the details of the expected instance and the actual instance into a CSV line format
		lo.Must0(w.Write([]string{
			string(instanceType.Name),
			fmt.Sprintf("%d", instanceType.Capacity.Memory().Value()/1024/1024),
			fmt.Sprintf("%d", instanceType.Capacity.Cpu().MilliValue()),
			fmt.Sprintf("%d", instanceType.Capacity.StorageEphemeral().Value()/1024/1024),
			fmt.Sprintf("%d", allocatable.Memory().Value()/1024/1024),
			fmt.Sprintf("%d", allocatable.Cpu().MilliValue()),
			fmt.Sprintf("%d", allocatable.StorageEphemeral().Value()/1024/1024),
			fmt.Sprintf("%d", node.Status.Capacity.Memory().Value()/1024/1024),
			fmt.Sprintf("%d", node.Status.Capacity.Cpu().MilliValue()),
			fmt.Sprintf("%d", node.Status.Capacity.StorageEphemeral().Value()/1024/1024),
			fmt.Sprintf("%d", node.Status.Allocatable.Memory().Value()/1024/1024),
			fmt.Sprintf("%d", node.Status.Allocatable.Cpu().MilliValue()),
			fmt.Sprintf("%d", node.Status.Allocatable.StorageEphemeral().Value()/1024/1024),
		}))
	}
}