Support KUBECONFIG with multiple kube config files (#1126)

* support KUBECONFIG with multiple kube config files
* use a more cross-platform friendly implementation to get the current users home dir

fission/function.go

@@ -754,8 +754,8 @@ func fnTest(c *cli.Context) error {
 	routerURL := os.Getenv("FISSION_ROUTER")
 	if len(routerURL) == 0 {
 		// Portforward to the fission router
-		localRouterPort := util.SetupPortForward(util.GetKubeConfigPath(),
-			util.GetFissionNamespace(), "application=fission-router")
+		localRouterPort := util.SetupPortForward(util.GetFissionNamespace(),
+			"application=fission-router")
 		routerURL = "127.0.0.1:" + localRouterPort
 	} else {
 		routerURL = strings.TrimPrefix(routerURL, "http://")

fission/support/dump.go

@@ -60,7 +60,7 @@ func DumpInfo(c *cli.Context) error {
 	}
 
 	client := util.GetApiClient(util.GetServerUrl())
-	_, k8sClient := util.GetKubernetesClient(util.GetKubeConfigPath())
+	_, k8sClient := util.GetKubernetesClient()
 
 	ress := map[string]resources.Resource{
 		// kubernetes info

fission/util/portforward.go

@@ -25,7 +25,7 @@ import (
 	"strings"
 	"time"
 
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	meta_v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/tools/portforward"
 	"k8s.io/client-go/transport/spdy"
@@ -39,9 +39,9 @@ import (
 // is found by looking for a service in the same namespace and using
 // its targetPort. Once the port forward is started, wait for it to
 // start accepting connections before returning.
-func SetupPortForward(kubeConfig, namespace, labelSelector string) string {
-	log.Verbose(2, "Setting up port forward to %s in namespace %s using the kubeconfig at %s",
-		labelSelector, namespace, kubeConfig)
+func SetupPortForward(namespace, labelSelector string) string {
+	log.Verbose(2, "Setting up port forward to %s in namespace %s",
+		labelSelector, namespace)
 
 	localPort, err := findFreePort()
 	if err != nil {
@@ -62,7 +62,7 @@ func SetupPortForward(kubeConfig, namespace, labelSelector string) string {
 
 	log.Verbose(2, "Starting port forward from local port %v", localPort)
 	go func() {
-		err := runPortForward(kubeConfig, labelSelector, localPort, namespace)
+		err := runPortForward(labelSelector, localPort, namespace)
 		if err != nil {
 			log.Fatal(fmt.Sprintf("Error forwarding to controller port: %s", err.Error()))
 		}
@@ -101,8 +101,8 @@ func findFreePort() (string, error) {
 }
 
 // runPortForward creates a local port forward to the specified pod
-func runPortForward(kubeConfig string, labelSelector string, localPort string, ns string) error {
-	config, clientset := GetKubernetesClient(kubeConfig)
+func runPortForward(labelSelector string, localPort string, ns string) error {
+	config, clientset := GetKubernetesClient()
 
 	log.Verbose(2, "Connected to Kubernetes API")
 

fission/util/util.go

@@ -19,6 +19,7 @@ package util
 import (
 	"fmt"
 	"os"
+	"os/user"
 	"path/filepath"
 	"regexp"
 	"strings"
@@ -53,20 +54,6 @@ func GetFissionNamespace() string {
 	return fissionNamespace
 }
 
-func GetKubeConfigPath() string {
-	kubeConfig := os.Getenv("KUBECONFIG")
-	if len(kubeConfig) == 0 {
-		home := os.Getenv("HOME")
-		kubeConfig = filepath.Join(home, ".kube", "config")
-
-		if _, err := os.Stat(kubeConfig); os.IsNotExist(err) {
-			log.Fatal("Couldn't find kubeconfig file. " +
-				"Set the KUBECONFIG environment variable to your kubeconfig's path.")
-		}
-	}
-	return kubeConfig
-}
-
 func GetServerUrl() string {
 	return GetApplicationUrl("application=fission-api")
 }
@@ -77,8 +64,7 @@ func GetApplicationUrl(selector string) string {
 	fissionUrl := os.Getenv("FISSION_URL")
 	if len(fissionUrl) == 0 {
 		fissionNamespace := GetFissionNamespace()
-		kubeConfig := GetKubeConfigPath()
-		localPort := SetupPortForward(kubeConfig, fissionNamespace, "application=fission-api")
+		localPort := SetupPortForward(fissionNamespace, "application=fission-api")
 		serverUrl = "http://127.0.0.1:" + localPort
 	} else {
 		serverUrl = fissionUrl
@@ -128,10 +114,35 @@ func KubifyName(old string) string {
 	return newName
 }
 
-func GetKubernetesClient(kubeConfig string) (*restclient.Config, *kubernetes.Clientset) {
-	config, err := clientcmd.BuildConfigFromFlags("", kubeConfig)
+// GetKubernetesClient builds a new kubernetes client. If the KUBECONFIG
+// environment variable is empty or doesn't exist, ~/.kube/config is used for
+// the kube config path
+func GetKubernetesClient() (*restclient.Config, *kubernetes.Clientset) {
+	loadingRules := clientcmd.NewDefaultClientConfigLoadingRules()
+
+	kubeConfigPath := os.Getenv("KUBECONFIG")
+	if len(kubeConfigPath) == 0 {
+		usr, err := user.Current()
+		if err != nil {
+			log.Fatal(fmt.Sprintf("Could not get the current users directory: %s", err))
+		}
+
+		kubeConfigPath = filepath.Join(usr.HomeDir, ".kube", "config")
+
+		if _, err := os.Stat(kubeConfigPath); os.IsNotExist(err) {
+			log.Fatal("Couldn't find kubeconfig file. " +
+				"Set the KUBECONFIG environment variable to your kubeconfig's path.")
+		}
+		loadingRules.ExplicitPath = kubeConfigPath
+		log.Verbose(2, "Using kubeconfig from %q", kubeConfigPath)
+	} else {
+		log.Verbose(2, "Using kubeconfig from environment %q", kubeConfigPath)
+	}
+
+	config, err := clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
+		loadingRules, &clientcmd.ConfigOverrides{}).ClientConfig()
 	if err != nil {
-		log.Fatal(fmt.Sprintf("Failed to connect to Kubernetes: %s", err))
+		log.Fatal(fmt.Sprintf("Failed to build Kubernetes config: %s", err))
 	}
 
 	clientset, err := kubernetes.NewForConfig(config)