Pass kubeconfig content around rather than file path

cli/cmd/cluster-apply.go

@@ -16,7 +16,6 @@ package cmd
 
 import (
 	"fmt"
-	"io/ioutil"
 
 	"github.com/pkg/errors"
 	log "github.com/sirupsen/logrus"
@@ -80,8 +79,12 @@ func runClusterApply(cmd *cobra.Command, args []string) {
 
 	fmt.Printf("\nYour configurations are stored in %s\n", assetDir)
 
-	kubeconfigPath := assetsKubeconfig(assetDir)
-	if err := verifyCluster(kubeconfigPath, p.Meta().ExpectedNodes); err != nil {
+	kubeconfig, err := getKubeconfig()
+	if err != nil {
+		ctxLogger.Fatalf("Failed to get kubeconfig: %v", err)
+	}
+
+	if err := verifyCluster(kubeconfig, p.Meta().ExpectedNodes); err != nil {
 		ctxLogger.Fatalf("Verify cluster: %v", err)
 	}
 
@@ -90,10 +93,10 @@ func runClusterApply(cmd *cobra.Command, args []string) {
 		fmt.Printf("\nEnsuring that cluster controlplane is up to date.\n")
 
 		cu := controlplaneUpdater{
-			kubeconfigPath: kubeconfigPath,
-			assetDir:       assetDir,
-			ctxLogger:      *ctxLogger,
-			ex:             *ex,
+			kubeconfig: kubeconfig,
+			assetDir:   assetDir,
+			ctxLogger:  *ctxLogger,
+			ex:         *ex,
 		}
 
 		releases := []string{"pod-checkpointer", "kube-apiserver", "kubernetes", "calico"}
@@ -119,18 +122,13 @@ func runClusterApply(cmd *cobra.Command, args []string) {
 	ctxLogger.Println("Applying component configuration")
 
 	if len(componentsToApply) > 0 {
-		if err := applyComponents(lokoConfig, kubeconfigPath, componentsToApply...); err != nil {
+		if err := applyComponents(lokoConfig, kubeconfig, componentsToApply...); err != nil {
 			ctxLogger.Fatalf("Applying component configuration failed: %v", err)
 		}
 	}
 }
 
-func verifyCluster(kubeconfigPath string, expectedNodes int) error {
-	kubeconfig, err := ioutil.ReadFile(kubeconfigPath) // #nosec G304
-	if err != nil {
-		return errors.Wrapf(err, "failed to read kubeconfig file")
-	}
-
+func verifyCluster(kubeconfig []byte, expectedNodes int) error {
 	cs, err := k8sutil.NewClientset(kubeconfig)
 	if err != nil {
 		return errors.Wrapf(err, "failed to set up clientset")

cli/cmd/cluster.go

@@ -148,10 +148,10 @@ func clusterExists(ctxLogger *logrus.Entry, ex *terraform.Executor) bool {
 }
 
 type controlplaneUpdater struct {
-	kubeconfigPath string
-	assetDir       string
-	ctxLogger      logrus.Entry
-	ex             terraform.Executor
+	kubeconfig []byte
+	assetDir   string
+	ctxLogger  logrus.Entry
+	ex         terraform.Executor
 }
 
 func (c controlplaneUpdater) getControlplaneChart(name string) (*chart.Chart, error) {
@@ -187,7 +187,7 @@ func (c controlplaneUpdater) upgradeComponent(component string) {
 		"component": component,
 	})
 
-	actionConfig, err := util.HelmActionConfig("kube-system", c.kubeconfigPath)
+	actionConfig, err := util.HelmActionConfig("kube-system", c.kubeconfig)
 	if err != nil {
 		ctxLogger.Fatalf("Failed initializing helm: %v", err)
 	}

cli/cmd/component-apply.go

@@ -68,7 +68,7 @@ func runApply(cmd *cobra.Command, args []string) {
 	}
 }
 
-func applyComponents(lokoConfig *config.Config, kubeconfig string, componentNames ...string) error {
+func applyComponents(lokoConfig *config.Config, kubeconfig []byte, componentNames ...string) error {
 	for _, componentName := range componentNames {
 		fmt.Printf("Applying component '%s'...\n", componentName)
 

cli/cmd/component-delete.go

@@ -15,20 +15,14 @@
 package cmd
 
 import (
-	"context"
 	"fmt"
-	"io/ioutil"
 	"strings"
 
 	log "github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
-	"helm.sh/helm/v3/pkg/action"
-	"k8s.io/apimachinery/pkg/api/errors"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"github.com/kinvolk/lokomotive/pkg/components"
 	"github.com/kinvolk/lokomotive/pkg/components/util"
-	"github.com/kinvolk/lokomotive/pkg/k8sutil"
 )
 
 var componentDeleteCmd = &cobra.Command{
@@ -102,11 +96,11 @@ func runDelete(cmd *cobra.Command, args []string) {
 	}
 }
 
-func deleteComponents(kubeconfig string, componentObjects ...components.Component) error {
+func deleteComponents(kubeconfig []byte, componentObjects ...components.Component) error {
 	for _, compObj := range componentObjects {
 		fmt.Printf("Deleting component '%s'...\n", compObj.Metadata().Name)
 
-		if err := deleteHelmRelease(compObj, kubeconfig, deleteNamespace); err != nil {
+		if err := util.UninstallComponent(compObj, kubeconfig, deleteNamespace); err != nil {
 			return err
 		}
 
@@ -118,75 +112,3 @@ func deleteComponents(kubeconfig string, componentObjects ...components.Componen
 
 	return nil
 }
-
-// deleteComponent deletes a component.
-func deleteHelmRelease(c components.Component, kubeconfig string, deleteNSBool bool) error {
-	name := c.Metadata().Name
-	if name == "" {
-		// This should never fail in real user usage, if this does that means the component was not
-		// created with all the needed information.
-		panic(fmt.Errorf("component name is empty"))
-	}
-
-	ns := c.Metadata().Namespace
-	if ns == "" {
-		// This should never fail in real user usage, if this does that means the component was not
-		// created with all the needed information.
-		panic(fmt.Errorf("component %s namespace is empty", name))
-	}
-
-	cfg, err := util.HelmActionConfig(ns, kubeconfig)
-	if err != nil {
-		return fmt.Errorf("failed preparing helm client: %w", err)
-	}
-
-	history := action.NewHistory(cfg)
-	// Check if the component's release exists. If it does only then proceed to delete.
-	//
-	// Note: It is assumed that this call will return error only when the release does not exist.
-	// The error check is ignored to make `lokoctl component delete ..` idempotent.
-	// We rely on the fact that the 'component name' == 'release name'. Since component's name is
-	// hardcoded and unlikely to change release name won't change as well. And they will be
-	// consistent if installed by lokoctl. So it is highly unlikely that following call will return
-	// any other error than "release not found".
-	if _, err := history.Run(name); err == nil {
-		uninstall := action.NewUninstall(cfg)
-
-		// Ignore the err when we have deleted the release already or it does not exist for some reason.
-		if _, err := uninstall.Run(name); err != nil {
-			return err
-		}
-	}
-
-	if deleteNSBool {
-		if err := deleteNS(ns, kubeconfig); err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-func deleteNS(ns string, kubeconfig string) error {
-	kubeconfigContent, err := ioutil.ReadFile(kubeconfig) // #nosec G304
-	if err != nil {
-		return fmt.Errorf("failed to read kubeconfig file: %v", err)
-	}
-
-	cs, err := k8sutil.NewClientset(kubeconfigContent)
-	if err != nil {
-		return err
-	}
-
-	// Delete the manually created namespace which was not created by helm.
-	if err = cs.CoreV1().Namespaces().Delete(context.TODO(), ns, metav1.DeleteOptions{}); err != nil {
-		// Ignore error when the namespace does not exist.
-		if errors.IsNotFound(err) {
-			return nil
-		}
-
-		return err
-	}
-
-	return nil
-}

cli/cmd/health.go

@@ -16,7 +16,6 @@ package cmd
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"text/tabwriter"
 
@@ -28,10 +27,9 @@ import (
 )
 
 var healthCmd = &cobra.Command{
-	Use:               "health",
-	Short:             "Get the health of a cluster",
-	Run:               runHealth,
-	PersistentPreRunE: doesKubeconfigExist,
+	Use:   "health",
+	Short: "Get the health of a cluster",
+	Run:   runHealth,
 }
 
 func init() {
@@ -49,12 +47,7 @@ func runHealth(cmd *cobra.Command, args []string) {
 		contextLogger.Fatalf("Error in finding kubeconfig file: %s", err)
 	}
 
-	kubeconfigContent, err := ioutil.ReadFile(kubeconfig) // #nosec G304
-	if err != nil {
-		contextLogger.Fatalf("Failed to read kubeconfig file: %v", err)
-	}
-
-	cs, err := k8sutil.NewClientset(kubeconfigContent)
+	cs, err := k8sutil.NewClientset(kubeconfig)
 	if err != nil {
 		contextLogger.Fatalf("Error in creating setting up Kubernetes client: %q", err)
 	}

cli/cmd/utils.go

@@ -16,12 +16,12 @@ package cmd
 
 import (
 	"fmt"
+	"io/ioutil"
 	"os"
 	"path/filepath"
 
 	"github.com/hashicorp/hcl/v2"
 	"github.com/mitchellh/go-homedir"
-	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 
 	"github.com/kinvolk/lokomotive/pkg/backend"
@@ -93,17 +93,20 @@ func getAssetDir() (string, error) {
 	return cfg.Meta().AssetDir, nil
 }
 
-// expandKubeconfigPath tries to expand ~ in the given kubeconfig path.
-// However, if that fails, it just returns original path as the best effort.
-func expandKubeconfigPath(path string) string {
+func getKubeconfig() ([]byte, error) {
+	path, err := getKubeconfigPath()
+	if err != nil {
+		return nil, fmt.Errorf("failed getting kubeconfig path: %w", err)
+	}
+
 	if expandedPath, err := homedir.Expand(path); err == nil {
-		return expandedPath
+		path = expandedPath
 	}
 
 	// homedir.Expand is too restrictive for the ~ prefix,
 	// i.e., it errors on "~somepath" which is a valid path,
-	// so just return the original path.
-	return path
+	// so just read from the original path.
+	return ioutil.ReadFile(path) // #nosec G304
 }
 
 // getKubeconfig finds the kubeconfig to be used. The precedence is the following:
@@ -113,7 +116,7 @@ func expandKubeconfigPath(path string) string {
 // - Asset directory from cluster configuration.
 // - KUBECONFIG environment variable.
 // - ~/.kube/config path, which is the default for kubectl.
-func getKubeconfig() (string, error) {
+func getKubeconfigPath() (string, error) {
 	assetKubeconfig, err := assetsKubeconfigPath()
 	if err != nil {
 		return "", fmt.Errorf("reading kubeconfig path from configuration failed: %w", err)
@@ -126,18 +129,13 @@ func getKubeconfig() (string, error) {
 		defaultKubeconfigPath,
 	}
 
-	return expandKubeconfigPath(pickString(paths...)), nil
-}
-
-// pickString returns first non-empty string.
-func pickString(options ...string) string {
-	for _, option := range options {
-		if option != "" {
-			return option
+	for _, path := range paths {
+		if path != "" {
+			return path, nil
 		}
 	}
 
-	return ""
+	return "", nil
 }
 
 // assetsKubeconfigPath reads the lokocfg configuration and returns
@@ -161,19 +159,6 @@ func assetsKubeconfig(assetDir string) string {
 	return filepath.Join(assetDir, "cluster-assets", "auth", "kubeconfig")
 }
 
-// doesKubeconfigExist checks if the kubeconfig provided by user exists
-func doesKubeconfigExist(*cobra.Command, []string) error {
-	var err error
-	kubeconfig, err := getKubeconfig()
-	if err != nil {
-		return err
-	}
-	if _, err = os.Stat(kubeconfig); os.IsNotExist(err) {
-		return fmt.Errorf("Kubeconfig %q not found", kubeconfig)
-	}
-	return err
-}
-
 func getLokoConfig() (*config.Config, hcl.Diagnostics) {
 	return config.LoadConfig(viper.GetString("lokocfg"), viper.GetString("lokocfg-vars"))
 }