refactor: Add option struct to optimize parameter transfer (#112)

Signed-off-by: Extreme <1403539044@qq.com>
Co-authored-by: Rob Scott <rob.scott87@gmail.com>

pkg/capacity/capacity.go

@@ -19,44 +19,43 @@ import (
 	"fmt"
 	"os"
 
-	"k8s.io/client-go/kubernetes"
-	metrics "k8s.io/metrics/pkg/client/clientset/versioned"
-
 	"github.com/robscott/kube-capacity/pkg/kube"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes"
 	v1beta1 "k8s.io/metrics/pkg/apis/metrics/v1beta1"
+	metrics "k8s.io/metrics/pkg/client/clientset/versioned"
 )
 
 // FetchAndPrint gathers cluster resource data and outputs it
-func FetchAndPrint(showContainers, showPods, showUtil, showPodCount, excludeTainted, availableFormat bool, podLabels, nodeLabels, namespaceLabels, namespace, kubeContext, kubeConfig, impersonateUser string, impersonateGroup string, output, sortBy string) {
-	clientset, err := kube.NewClientSet(kubeContext, kubeConfig, impersonateUser, impersonateGroup)
+func FetchAndPrint(opts Options) {
+	clientset, err := kube.NewClientSet(opts.KubeConfig, opts.KubeContext, opts.ImpersonateUser, opts.ImpersonateGroup)
 	if err != nil {
 		fmt.Printf("Error connecting to Kubernetes: %v\n", err)
 		os.Exit(1)
 	}
 
-	podList, nodeList := getPodsAndNodes(clientset, excludeTainted, podLabels, nodeLabels, namespaceLabels, namespace)
+	podList, nodeList := getPodsAndNodes(clientset, opts.ExcludeTainted, opts.PodLabels, opts.NodeLabels, opts.NamespaceLabels, opts.Namespace)
 	var pmList *v1beta1.PodMetricsList
 	var nmList *v1beta1.NodeMetricsList
 
-	if showUtil {
-		mClientset, err := kube.NewMetricsClientSet(kubeContext, kubeConfig)
+	if opts.ShowUtil {
+		mClientset, err := kube.NewMetricsClientSet(opts.KubeContext, opts.KubeConfig)
 		if err != nil {
 			fmt.Printf("Error connecting to Metrics API: %v\n", err)
 			os.Exit(4)
 		}
 
-		pmList = getPodMetrics(mClientset, namespace)
-		if namespace == "" && namespaceLabels == "" {
-			nmList = getNodeMetrics(mClientset, nodeLabels)
+		pmList = getPodMetrics(mClientset, opts.Namespace)
+		if opts.Namespace == "" && opts.NamespaceLabels == "" {
+			nmList = getNodeMetrics(mClientset, opts.NodeLabels)
 		}
 	}
 
 	cm := buildClusterMetric(podList, pmList, nodeList, nmList)
-	showNamespace := namespace == ""
+	showNamespace := opts.Namespace == ""
 
-	printList(&cm, showContainers, showPods, showUtil, showPodCount, showNamespace, output, sortBy, availableFormat)
+	printList(&cm, opts.ShowContainers, opts.ShowPods, opts.ShowUtil, opts.ShowPodCount, showNamespace, opts.OutputFormat, opts.SortBy, opts.AvailableFormat)
 }
 
 func getPodsAndNodes(clientset kubernetes.Interface, excludeTainted bool, podLabels, nodeLabels, namespaceLabels, namespace string) (*corev1.PodList, *corev1.NodeList) {

pkg/capacity/options.go

@@ -0,0 +1,22 @@
+package capacity
+
+// Options is a struct containing the command line options
+// FetchAndPrint depends on
+type Options struct {
+	ShowContainers   bool
+	ShowPods         bool
+	ShowUtil         bool
+	ShowPodCount     bool
+	PodLabels        string
+	NodeLabels       string
+	ExcludeTainted   bool
+	NamespaceLabels  string
+	Namespace        string
+	KubeContext      string
+	KubeConfig       string
+	OutputFormat     string
+	SortBy           string
+	AvailableFormat  bool
+	ImpersonateUser  string
+	ImpersonateGroup string
+}

pkg/cmd/root.go

@@ -22,22 +22,7 @@ import (
 	"github.com/spf13/cobra"
 )
 
-var showContainers bool
-var showPods bool
-var showUtil bool
-var showPodCount bool
-var podLabels string
-var nodeLabels string
-var excludeTainted bool
-var namespaceLabels string
-var namespace string
-var kubeContext string
-var kubeConfig string
-var outputFormat string
-var sortBy string
-var availableFormat bool
-var impersonateUser string
-var impersonateGroup string
+var opts capacity.Options
 
 var rootCmd = &cobra.Command{
 	Use:   "kube-capacity",
@@ -48,50 +33,49 @@ var rootCmd = &cobra.Command{
 			fmt.Printf("Error parsing flags: %v", err)
 		}
 
-		if err := validateOutputType(outputFormat); err != nil {
+		if err := validateOutputType(opts.OutputFormat); err != nil {
 			fmt.Println(err)
 			os.Exit(1)
 		}
 
-		capacity.FetchAndPrint(showContainers, showPods, showUtil, showPodCount, excludeTainted, availableFormat, podLabels,
-			nodeLabels, namespaceLabels, namespace, kubeContext, kubeConfig, impersonateUser, impersonateGroup, outputFormat, sortBy)
+		capacity.FetchAndPrint(opts)
 	},
 }
 
 func init() {
-	rootCmd.PersistentFlags().BoolVarP(&showContainers,
+	rootCmd.PersistentFlags().BoolVarP(&opts.ShowContainers,
 		"containers", "c", false, "includes containers in output")
-	rootCmd.PersistentFlags().BoolVarP(&showPods,
+	rootCmd.PersistentFlags().BoolVarP(&opts.ShowPods,
 		"pods", "p", false, "includes pods in output")
-	rootCmd.PersistentFlags().BoolVarP(&showUtil,
+	rootCmd.PersistentFlags().BoolVarP(&opts.ShowUtil,
 		"util", "u", false, "includes resource utilization in output")
-	rootCmd.PersistentFlags().BoolVarP(&showPodCount,
+	rootCmd.PersistentFlags().BoolVarP(&opts.ShowPodCount,
 		"pod-count", "", false, "includes pod count per node in output")
-	rootCmd.PersistentFlags().BoolVarP(&availableFormat,
-		"available", "a", false, "includes quantity available instead of percentage used (ignored with csv or tsv output types)")
-	rootCmd.PersistentFlags().StringVarP(&podLabels,
+	rootCmd.PersistentFlags().BoolVarP(&opts.AvailableFormat,
+		"available", "a", false, "includes quantity available instead of percentage used")
+	rootCmd.PersistentFlags().StringVarP(&opts.PodLabels,
 		"pod-labels", "l", "", "labels to filter pods with")
-	rootCmd.PersistentFlags().StringVarP(&nodeLabels,
+	rootCmd.PersistentFlags().StringVarP(&opts.NodeLabels,
 		"node-labels", "", "", "labels to filter nodes with")
-	rootCmd.PersistentFlags().BoolVarP(&excludeTainted,
+	rootCmd.PersistentFlags().BoolVarP(&opts.ExcludeTainted,
 		"no-taint", "", false, "exclude nodes with taints")
-	rootCmd.PersistentFlags().StringVarP(&namespaceLabels,
+	rootCmd.PersistentFlags().StringVarP(&opts.NamespaceLabels,
 		"namespace-labels", "", "", "labels to filter namespaces with")
-	rootCmd.PersistentFlags().StringVarP(&namespace,
+	rootCmd.PersistentFlags().StringVarP(&opts.Namespace,
 		"namespace", "n", "", "only include pods from this namespace")
-	rootCmd.PersistentFlags().StringVarP(&kubeContext,
+	rootCmd.PersistentFlags().StringVarP(&opts.KubeContext,
 		"context", "", "", "context to use for Kubernetes config")
-	rootCmd.PersistentFlags().StringVarP(&kubeConfig,
+	rootCmd.PersistentFlags().StringVarP(&opts.KubeConfig,
 		"kubeconfig", "", "", "kubeconfig file to use for Kubernetes config")
-	rootCmd.PersistentFlags().StringVarP(&sortBy,
+	rootCmd.PersistentFlags().StringVarP(&opts.SortBy,
 		"sort", "", "name",
 		fmt.Sprintf("attribute to sort results by (supports: %v)", capacity.SupportedSortAttributes))
-	rootCmd.PersistentFlags().StringVarP(&outputFormat,
+	rootCmd.PersistentFlags().StringVarP(&opts.OutputFormat,
 		"output", "o", capacity.TableOutput,
 		fmt.Sprintf("output format for information (supports: %v)", capacity.SupportedOutputs()))
-	rootCmd.PersistentFlags().StringVarP(&impersonateUser,
+	rootCmd.PersistentFlags().StringVarP(&opts.ImpersonateUser,
 		"as", "", "", "user to impersonate kube-capacity with")
-	rootCmd.PersistentFlags().StringVarP(&impersonateGroup,
+	rootCmd.PersistentFlags().StringVarP(&opts.ImpersonateGroup,
 		"as-group", "", "", "group to impersonate kube-capacity with")
 }