feedback: de-duplicate loadRESTConfig

pkg/agent/run.go

@@ -17,18 +17,17 @@ import (
 
 	"github.com/cenkalti/backoff"
 	"github.com/hashicorp/go-multierror"
-	"github.com/jetstack/preflight/pkg/logs"
 	json "github.com/json-iterator/go"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/spf13/cobra"
-	"k8s.io/client-go/rest"
-	"k8s.io/client-go/tools/clientcmd"
 	"sigs.k8s.io/controller-runtime/pkg/manager"
 
 	"github.com/jetstack/preflight/api"
 	"github.com/jetstack/preflight/pkg/client"
 	"github.com/jetstack/preflight/pkg/datagatherer"
+	"github.com/jetstack/preflight/pkg/kubeconfig"
+	"github.com/jetstack/preflight/pkg/logs"
 	"github.com/jetstack/preflight/pkg/version"
 )
 
@@ -342,7 +341,7 @@ func getConfiguration() (Config, client.Client) {
 			logs.Log.Printf(`ignoring venafi-cloud.uploader_id. In Venafi Connection mode, this field is not needed.`)
 		}
 
-		cfg, err := loadRESTConfig("")
+		cfg, err := kubeconfig.LoadRESTConfig("")
 		if err != nil {
 			logs.Log.Fatalf("failed to load kubeconfig: %v", err)
 		}
@@ -568,28 +567,3 @@ func getInClusterNamespace() (string, error) {
 	}
 	return string(namespace), nil
 }
-
-func loadRESTConfig(path string) (*rest.Config, error) {
-	switch path {
-	// If the kubeconfig path is not provided, use the default loading rules
-	// so we read the regular KUBECONFIG variable or create a non-interactive
-	// client for agents running in cluster
-	case "":
-		loadingrules := clientcmd.NewDefaultClientConfigLoadingRules()
-		cfg, err := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
-			loadingrules, &clientcmd.ConfigOverrides{}).ClientConfig()
-		if err != nil {
-			return nil, fmt.Errorf("failed to load kubeconfig: %w", err)
-		}
-		return cfg, nil
-	// Otherwise use the explicitly named kubeconfig file.
-	default:
-		cfg, err := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
-			&clientcmd.ClientConfigLoadingRules{ExplicitPath: path},
-			&clientcmd.ConfigOverrides{}).ClientConfig()
-		if err != nil {
-			return nil, fmt.Errorf("failed to load kubeconfig from %s: %w", path, err)
-		}
-		return cfg, nil
-	}
-}

pkg/datagatherer/k8s/client.go

@@ -6,15 +6,15 @@ import (
 	"k8s.io/client-go/discovery"
 	"k8s.io/client-go/dynamic"
 	"k8s.io/client-go/kubernetes"
-	"k8s.io/client-go/rest"
-	"k8s.io/client-go/tools/clientcmd"
+
+	"github.com/jetstack/preflight/pkg/kubeconfig"
 )
 
 // NewDynamicClient creates a new 'dynamic' clientset using the provided kubeconfig.
 // If kubeconfigPath is not set/empty, it will attempt to load configuration using
 // the default loading rules.
 func NewDynamicClient(kubeconfigPath string) (dynamic.Interface, error) {
-	cfg, err := loadRESTConfig(kubeconfigPath)
+	cfg, err := kubeconfig.LoadRESTConfig(kubeconfigPath)
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
@@ -31,7 +31,7 @@ func NewDynamicClient(kubeconfigPath string) (dynamic.Interface, error) {
 func NewDiscoveryClient(kubeconfigPath string) (discovery.DiscoveryClient, error) {
 	var discoveryClient *discovery.DiscoveryClient
 
-	cfg, err := loadRESTConfig(kubeconfigPath)
+	cfg, err := kubeconfig.LoadRESTConfig(kubeconfigPath)
 	if err != nil {
 		return discovery.DiscoveryClient{}, errors.WithStack(err)
 	}
@@ -49,7 +49,7 @@ func NewDiscoveryClient(kubeconfigPath string) (discovery.DiscoveryClient, error
 // the default loading rules.
 func NewClientSet(kubeconfigPath string) (kubernetes.Interface, error) {
 	var clientset *kubernetes.Clientset
-	cfg, err := loadRESTConfig(kubeconfigPath)
+	cfg, err := kubeconfig.LoadRESTConfig(kubeconfigPath)
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
@@ -59,28 +59,3 @@ func NewClientSet(kubeconfigPath string) (kubernetes.Interface, error) {
 	}
 	return clientset, nil
 }
-
-func loadRESTConfig(path string) (*rest.Config, error) {
-	switch path {
-	// If the kubeconfig path is not provided, use the default loading rules
-	// so we read the regular KUBECONFIG variable or create a non-interactive
-	// client for agents running in cluster
-	case "":
-		loadingrules := clientcmd.NewDefaultClientConfigLoadingRules()
-		cfg, err := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
-			loadingrules, &clientcmd.ConfigOverrides{}).ClientConfig()
-		if err != nil {
-			return nil, errors.WithStack(err)
-		}
-		return cfg, nil
-	// Otherwise use the explicitly named kubeconfig file.
-	default:
-		cfg, err := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
-			&clientcmd.ClientConfigLoadingRules{ExplicitPath: path},
-			&clientcmd.ConfigOverrides{}).ClientConfig()
-		if err != nil {
-			return nil, errors.WithStack(err)
-		}
-		return cfg, nil
-	}
-}

pkg/kubeconfig/kubeconfig.go

@@ -0,0 +1,35 @@
+package kubeconfig
+
+import (
+	"github.com/pkg/errors"
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
+)
+
+// LoadRESTConfig loads the kube config from the provided path. If the path is
+// empty, the kube config will be loaded from KUBECONFIG, and if KUBECONFIG
+// isn't set, the in-cluster config will be used.
+func LoadRESTConfig(path string) (*rest.Config, error) {
+	switch path {
+	// If the kubeconfig path is not provided, use the default loading rules
+	// so we read the regular KUBECONFIG variable or create a non-interactive
+	// client for agents running in cluster
+	case "":
+		loadingrules := clientcmd.NewDefaultClientConfigLoadingRules()
+		cfg, err := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
+			loadingrules, &clientcmd.ConfigOverrides{}).ClientConfig()
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+		return cfg, nil
+	// Otherwise use the explicitly named kubeconfig file.
+	default:
+		cfg, err := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
+			&clientcmd.ClientConfigLoadingRules{ExplicitPath: path},
+			&clientcmd.ConfigOverrides{}).ClientConfig()
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+		return cfg, nil
+	}
+}