allow context override with -x

txn2 · Nov 24, 2018 · 6e4bb36 · 6e4bb36
1 parent b2a27f6
commit 6e4bb36
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Showing 3 changed files with 30 additions and 19 deletions.
diff --git a/cmd/kubefwd/kubefwd.go b/cmd/kubefwd/kubefwd.go
@@ -31,7 +31,7 @@ func newRootCmd() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "kubefwd",
 		Short: "Expose Kubernetes services for local development.",
-		Example: "  kubefwd services --help\n" +
+		Example: " kubefwd services --help\n" +
 			"  kubefwd svc -n the-project\n" +
 			"  kubefwd svc -n the-project -l app=wx,component=api\n" +
 			"  kubefwd svc -n default -n the-project\n",

diff --git a/cmd/kubefwd/services/services.go b/cmd/kubefwd/services/services.go
@@ -35,6 +35,7 @@ import (
 )
 
 var namespaces []string
+var contexts []string
 
 func init() {
 	cfgFilePath := ""
@@ -53,6 +54,7 @@ func init() {
 	}
 
 	Cmd.Flags().StringP("kubeconfig", "c", cfgFilePath, "absolute path to a kubectl config file")
+	Cmd.Flags().StringSliceVarP(&contexts, "context", "x", []string{}, "specify a context to override the current context")
 	Cmd.Flags().StringSliceVarP(&namespaces, "namespace", "n", []string{}, "Specify a namespace. Specify multiple namespaces by duplicating this argument.")
 	Cmd.Flags().StringP("selector", "l", "", "Selector (label query) to filter on; supports '=', '==', and '!=' (e.g. -l key1=value1,key2=value2).")
 }
@@ -91,30 +93,35 @@ Try:
 		}
 
 		// k8s rest config
-		config := utils.K8sConfig(cmd)
-		selector := cmd.Flag("selector").Value.String()
+		// TODO: Future support for multiple contexts
+		config := utils.K8sConfig(cmd, contexts)
 
-		if len(namespaces) < 1 {
-			namespaces = []string{"default"}
+		// create the client set
+		clientSet, err := kubernetes.NewForConfig(config)
+		if err != nil {
+			panic(err.Error())
 		}
 
+		// labels selector to filter services
+		// see: https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/
+		selector := cmd.Flag("selector").Value.String()
 		listOptions := metav1.ListOptions{}
 		if selector != "" {
 			listOptions.LabelSelector = selector
 		}
 
-		// create the client set
-		clientSet, err := kubernetes.NewForConfig(config)
-		if err != nil {
-			panic(err.Error())
+		// if no namespaces were specified, explicitly set
+		// one to "default"
+		if len(namespaces) < 1 {
+			namespaces = []string{"default"}
 		}
 
-		wg := &sync.WaitGroup{}
-
 		// ipC is the class C for the local IP address
 		// increment this for each cluster
 		ipC := 27
 
+		wg := &sync.WaitGroup{}
+
 		for i, namespace := range namespaces {
 			err = fwdServices(FwdServiceOpts{
 				Wg:           wg,

diff --git a/pkg/utils/utils.go b/pkg/utils/utils.go
@@ -64,27 +64,31 @@ func (p *Publisher) Write(b []byte) (int, error) {
 	return 0, nil
 }
 
-func K8sConfig(cmd *cobra.Command) *restclient.Config {
+func K8sConfig(cmd *cobra.Command, contexts []string) *restclient.Config {
 
 	cfgFilePath := cmd.Flag("kubeconfig").Value.String()
-	namespace := cmd.Flag("namespace").Value.String()
-
-	if namespace == "" {
-		namespace = "default"
-	}
 
 	if cfgFilePath == "" {
 		fmt.Println("No config found. Use --kubeconfig to specify one")
 		os.Exit(1)
 	}
 
+	overrides := &clientcmd.ConfigOverrides{}
+
+	if len(contexts) > 0 {
+		overrides = &clientcmd.ConfigOverrides{CurrentContext: contexts[0]}
+	}
+
 	// use the current context in kubeconfig
-	config, err := clientcmd.BuildConfigFromFlags("", cfgFilePath)
+	restConfig, err := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
+		&clientcmd.ClientConfigLoadingRules{ExplicitPath: cfgFilePath},
+		overrides,
+	).ClientConfig()
 	if err != nil {
 		panic(err.Error())
 	}
 
-	return config
+	return restConfig
 }
 
 type PortForwardOpts struct {