[operator] Add kube clientcmd util

pkg/util/kube/util.go

@@ -0,0 +1,56 @@
+package kube
+
+import (
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
+
+	"os"
+)
+
+func DefaultRestConfig(kubeconfig, context string, fns ...func(config *rest.Config)) (*rest.Config, error) {
+}
+
+func BuildClientConfig(kubeconfig, context string) (*rest.Config, error) {
+	c, err := BuildClientCmd(kubeconfig, context).ClientConfig()
+	if err != nil {
+		return nil, err
+	}
+	return
+}
+
+func SetRestDefaults(config *rest.Config) (*rest.Config) {
+	if config.GroupVersion == nil || config.GroupVersion.Empty() {
+		config.GroupVersion = &corev1.SchemeGroupVersion
+	}
+	if len(config.APIPath) == 0 {
+		if len(config.GroupVersion.Group) == 0 {
+			config.APIPath = "/api"
+		} else {
+			config.APIPath = "/apis"
+		}
+	}
+	if config.NegotiatedSerializer == nil {
+	}
+	return config
+}
+
+func BuildClientCmd(kubeconfig, context string, overrides ...func(configOverrides *clientcmd.ConfigOverrides)) clientcmd.ClientConfig {
+	if kubeconfig != "" {
+		info, err := os.Stat(kubeconfig)
+		if err != nil || info.Size() == 0 {
+			kubeconfig = ""
+		}
+	}
+	loadingRules := clientcmd.NewDefaultClientConfigLoadingRules()
+	loadingRules.DefaultClientConfig = &clientcmd.DefaultClientConfig
+	loadingRules.ExplicitPath = kubeconfig
+	configOverrides := &clientcmd.ConfigOverrides{
+		ClusterDefaults: clientcmd.ClusterDefaults,
+		CurrentContext:  context,
+	}
+	for _, fn := range overrides {
+		fn(configOverrides)
+	}
+	return clientcmd.NewNonInteractiveDeferredLoadingClientConfig(loadingRules, configOverrides)
+}