auto-detect gce and do not enable gcp auth addon

cmd/minikube/cmd/config/enable.go

@@ -22,6 +22,7 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 	"k8s.io/minikube/pkg/addons"
+	"k8s.io/minikube/pkg/addons/gcpauth"
 	"k8s.io/minikube/pkg/minikube/config"
 	"k8s.io/minikube/pkg/minikube/constants"
 	"k8s.io/minikube/pkg/minikube/exit"
@@ -42,7 +43,7 @@ var addonsEnableCmd = &cobra.Command{
 		addon := args[0]
 		// replace heapster as metrics-server because heapster is deprecated
 		if addon == "heapster" {
-			out.Styled(style.Waiting, "enable metrics-server addon instead of heapster addon because heapster is deprecated")
+			out.Styled(style.Waiting, "using metrics-server addon, heapster is deprecated")
 			addon = "metrics-server"
 		}
 		viper.Set(config.AddonImages, images)
@@ -76,5 +77,6 @@ var (
 func init() {
 	addonsEnableCmd.Flags().StringVar(&images, "images", "", "Images used by this addon. Separated by commas.")
 	addonsEnableCmd.Flags().StringVar(&registries, "registries", "", "Registries used by this addon. Separated by commas.")
+	addonsEnableCmd.Flags().BoolVar(&gcpauth.Force, "force", false, "If true, will force gcp-auth addon to be enabled on GCE.")
 	AddonsCmd.AddCommand(addonsEnableCmd)
 }

pkg/addons/gcpauth/enable.go

@@ -19,10 +19,9 @@ package gcpauth
 import (
 	"bytes"
 	"context"
-	"io/ioutil"
+	"net/http"
 	"os"
 	"os/exec"
-	"path"
 	"strconv"
 
 	"github.com/pkg/errors"
@@ -41,6 +40,9 @@ const (
 	projectPath     = "/var/lib/minikube/google_cloud_project"
 )
 
+// Force is used to override our GCE check for the addon
+var Force bool = false
+
 // EnableOrDisable enables or disables the metadata addon depending on the val parameter
 func EnableOrDisable(cfg *config.ClusterConfig, name string, val string) error {
 	enable, err := strconv.ParseBool(val)
@@ -54,6 +56,10 @@ func EnableOrDisable(cfg *config.ClusterConfig, name string, val string) error {
 }
 
 func enableAddon(cfg *config.ClusterConfig) error {
+	if !Force && isGCE() {
+		exit.Message(reason.InternalCredsNotFound, "It seems that you are running in GCE, which means authentication should work without the GCP Auth addon. If you would still like to use this addon, use the --force flag.")
+	}
+
 	// Grab command runner from running cluster
 	cc := mustload.Running(cfg.Name)
 	r := cc.CP.Runner
@@ -65,20 +71,9 @@ func enableAddon(cfg *config.ClusterConfig) error {
 		exit.Message(reason.InternalCredsNotFound, "Could not find any GCP credentials. Either run `gcloud auth application-default login` or set the GOOGLE_APPLICATION_CREDENTIALS environment variable to the path of your credentials file.")
 	}
 
+	// Don't mount in empty credentials file
 	if creds.JSON == nil {
-		// Cloud Shell sends credential files to an unusual location, let's check that location
-		// For example, CLOUDSDK_CONFIG=/tmp/tmp.cflmvysoQE
-		if e := os.Getenv("CLOUDSDK_CONFIG"); e != "" {
-			credFile := path.Join(e, "application_default_credentials.json")
-			b, err := ioutil.ReadFile(credFile)
-			if err != nil {
-				exit.Message(reason.InternalCredsNotFound, "Could not find any GCP credentials. Either run `gcloud auth application-default login` or set the GOOGLE_APPLICATION_CREDENTIALS environment variable to the path of your credentials file.")
-			}
-			creds.JSON = b
-		} else {
-			// We don't currently support authentication through the metadata server
-			exit.Message(reason.InternalCredsNotFound, "Could not find any GCP credentials. Either run `gcloud auth application-default login` or set the GOOGLE_APPLICATION_CREDENTIALS environment variable to the path of your credentials file.")
-		}
+		exit.Message(reason.InternalCredsNotFound, "Could not find any GCP credentials. Either run `gcloud auth application-default login` or set the GOOGLE_APPLICATION_CREDENTIALS environment variable to the path of your credentials file.")
 	}
 
 	f := assets.NewMemoryAssetTarget(creds.JSON, credentialsPath, "0444")
@@ -134,3 +129,16 @@ func disableAddon(cfg *config.ClusterConfig) error {
 
 	return nil
 }
+
+func isGCE() bool {
+	resp, err := http.Get("http://metadata.google.internal")
+	if err != nil {
+		return false
+	}
+
+	if resp.Header.Get("Metadata-Flavor") == "Google" {
+		return true
+	}
+
+	return false
+}

pkg/minikube/node/start.go

@@ -37,6 +37,7 @@ import (
 	kconst "k8s.io/kubernetes/cmd/kubeadm/app/constants"
 	cmdcfg "k8s.io/minikube/cmd/minikube/cmd/config"
 	"k8s.io/minikube/pkg/addons"
+	"k8s.io/minikube/pkg/addons/gcpauth"
 	"k8s.io/minikube/pkg/drivers/kic/oci"
 	"k8s.io/minikube/pkg/kapi"
 	"k8s.io/minikube/pkg/minikube/bootstrapper"
@@ -164,6 +165,9 @@ func Start(starter Starter, apiServer bool) (*kubeconfig.Settings, error) {
 
 	// enable addons, both old and new!
 	if starter.ExistingAddons != nil {
+		if viper.GetBool("force") {
+			gcpauth.Force = true
+		}
 		wg.Add(1)
 		go addons.Start(&wg, starter.Cfg, starter.ExistingAddons, config.AddonList)
 	}

site/content/en/docs/commands/addons.md

@@ -128,6 +128,7 @@ minikube addons enable dashboard
 ### Options
 
 ```
+      --force               If true, will force gcp-auth addon to be enabled on GCE.
       --images string       Images used by this addon. Separated by commas.
       --registries string   Registries used by this addon. Separated by commas.
 ```

test/integration/addons_test.go

@@ -58,7 +58,7 @@ func TestAddons(t *testing.T) {
 		t.Fatalf("Failed setting GOOGLE_CLOUD_PROJECT env var: %v", err)
 	}
 
-	args := append([]string{"start", "-p", profile, "--wait=true", "--memory=4000", "--alsologtostderr", "--addons=registry", "--addons=metrics-server", "--addons=olm", "--addons=volumesnapshots", "--addons=csi-hostpath-driver", "--addons=gcp-auth"}, StartArgs()...)
+	args := append([]string{"start", "-p", profile, "--wait=true", "--memory=4000", "--alsologtostderr", "--force", "--addons=registry", "--addons=metrics-server", "--addons=olm", "--addons=volumesnapshots", "--addons=csi-hostpath-driver", "--addons=gcp-auth"}, StartArgs()...)
 	if !(runtime.GOOS == "darwin" && KicDriver()) { // macos docker driver does not support ingress
 		args = append(args, "--addons=ingress")
 	}