Support check command with multiple config files

Resolves: #472
Signed-off-by: Alexei Ledenev <alexei.led@gmail.com>

cmd/flux/check.go

@@ -28,7 +28,6 @@ import (
 	"github.com/spf13/cobra"
 	apimachineryversion "k8s.io/apimachinery/pkg/version"
 	"k8s.io/client-go/kubernetes"
-	"k8s.io/client-go/tools/clientcmd"
 )
 
 var checkCmd = &cobra.Command{
@@ -133,7 +132,7 @@ func kubectlCheck(ctx context.Context, version string) bool {
 }
 
 func kubernetesCheck(version string) bool {
-	cfg, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
+	cfg, err := utils.KubeConfig(kubeconfig, kubecontext)
 	if err != nil {
 		logger.Failuref("Kubernetes client initialization failed: %s", err.Error())
 		return false

internal/utils/utils.go

@@ -34,6 +34,7 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	rbacv1 "k8s.io/api/rbac/v1"
 	apiruntime "k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/clientcmd"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/kustomize/api/filesys"
@@ -134,7 +135,7 @@ func ExecTemplate(obj interface{}, tmpl, filename string) error {
 	return file.Sync()
 }
 
-func KubeClient(kubeConfigPath string, kubeContext string) (client.Client, error) {
+func KubeConfig(kubeConfigPath string, kubeContext string) (*rest.Config, error) {
 	configFiles := SplitKubeConfigPath(kubeConfigPath)
 	configOverrides := clientcmd.ConfigOverrides{}
 
@@ -147,6 +148,15 @@ func KubeClient(kubeConfigPath string, kubeContext string) (client.Client, error
 		&configOverrides,
 	).ClientConfig()
 
+	if err != nil {
+		return nil, fmt.Errorf("kubernetes configuration load failed: %w", err)
+	}
+
+	return cfg, nil
+}
+
+func KubeClient(kubeConfigPath string, kubeContext string) (client.Client, error) {
+	cfg, err := KubeConfig(kubeConfigPath, kubeContext)
 	if err != nil {
 		return nil, fmt.Errorf("kubernetes client initialization failed: %w", err)
 	}