Merge pull request #61 from DanHam/respect-context

Use context passed via the commandline when discovering cluster version

internal/kubehelper/client.go

@@ -6,17 +6,27 @@ import (
 	"time"
 
 	"k8s.io/client-go/kubernetes"
-	restclient "k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/clientcmd"
 )
 
 func createKubeClient(timeout int64) (*kubernetes.Clientset, error) {
 	var cliKubeconfig string
+	var cliKubecontext string
+
+	// If there are mutiple occurrences of options supplied to kubectl, the
+	// last one takes precedence. The continue statements below ensures kuberlr
+	// preserves this behaviour
 	for index := 1; index < len(os.Args); index++ {
+		if index+1 < len(os.Args) && os.Args[index] == "--context" {
+			cliKubecontext = os.Args[index+1]
+			continue
+		}
+		if strings.HasPrefix(os.Args[index], "--context=") {
+			cliKubecontext = strings.TrimPrefix(os.Args[index], "--context=")
+			continue
+		}
 		if index+1 < len(os.Args) && os.Args[index] == "--kubeconfig" {
 			cliKubeconfig = os.Args[index+1]
-			// don't break here; in case there are multiple --kubeconfig options,
-			// the last one takes precedence
 			continue
 		}
 		if strings.HasPrefix(os.Args[index], "--kubeconfig=") {
@@ -28,34 +38,32 @@ func createKubeClient(timeout int64) (*kubernetes.Clientset, error) {
 		}
 	}
 
-	var restConfig *restclient.Config
-	var err error
-
+	// Let the NewDefaultClientConfigLoadingRules do the heavy lifting like
+	// parsing the KUBECONFIG value
+	// TIL: it's possible to specify multiple kubeconfig files via KUBECONFIG
+	// For example: `KUBECONFIG=~/cluster1.yaml:~/cluster2.yaml`
+	// See https://github.com/kubernetes/kubernetes/issues/46381#issuecomment-303926031
+	//
+	// The NewDefaultClientConfigLoadingRules function has all the logic built
+	// inside of it that handles this special case.
+	clientConfLoadingrules := clientcmd.NewDefaultClientConfigLoadingRules()
 	if cliKubeconfig != "" {
-		// give precedence to --kubeconfig flag
-		restConfig, err = clientcmd.BuildConfigFromFlags("", cliKubeconfig)
-	} else {
-		// Let the NewDefaultClientConfigLoadingRules do the heavy lifting like
-		// parsing the KUBECONFIG value
-		// TIL: it's possible to specify multiple kubeconfig files via KUBECONFIG
-		// For example: `KUBECONFIG=~/cluster1.yaml:~/cluster2.yaml`
-		// See https://github.com/kubernetes/kubernetes/issues/46381#issuecomment-303926031
-		//
-		// The NewDefaultClientConfigLoadingRules function has all the logic built
-		// inside of it that handles this special case.
-		clientConfLoadingrules := clientcmd.NewDefaultClientConfigLoadingRules()
-
-		restConfig, err = clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
-			clientConfLoadingrules,
-			&clientcmd.ConfigOverrides{}).ClientConfig()
+		clientConfLoadingrules.ExplicitPath = cliKubeconfig
+	}
+	clientConfOverrides := &clientcmd.ConfigOverrides{}
+	if cliKubecontext != "" {
+		clientConfOverrides.CurrentContext = cliKubecontext
 	}
+	restConfig, err := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
+		clientConfLoadingrules,
+		clientConfOverrides).ClientConfig()
 	if err != nil {
 		return nil, err
 	}
 
-	// lower the timeout value
+	// Lower the timeout value
 	restConfig.Timeout = time.Duration(timeout) * time.Second
 
-	// create the clientset
+	// Create the clientset
 	return kubernetes.NewForConfig(restConfig)
 }