Simulate cascading PersistPreRunE calls

Because cobra will only call the last PersistPreRunE we need to
simulate a cascading run.
spf13/cobra#252

We also switches every function to `...E` alternative

cmd/aws.go

@@ -3,7 +3,6 @@ package cmd
 
 import (
 	"fmt"
-	"os"
 
 	"github.com/mateimicu/kdiscover/internal"
 	"github.com/spf13/cobra"
@@ -20,7 +19,20 @@ func newAWSCommand() *cobra.Command {
 	AWSCommand := &cobra.Command{
 		Use:   "aws",
 		Short: "Work with AWS EKS clusters",
-		PersistentPreRun: func(cmd *cobra.Command, args []string) {
+		PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
+			// Because cobra will only run the last PersistentPreRunE
+			// we need to search for the root and run the function.
+			// This is not a robust solution as there may be multiple
+			// PersistentPreRunE function between the leaf command and root
+			// also this assumes that this is the root one
+			// An issue about this https://github.com/spf13/cobra/issues/252
+			root := cmd
+			for ; root.HasParent(); root = root.Parent() {
+			}
+			err := root.PersistentPreRunE(cmd, args)
+			if err != nil {
+				return err
+			}
 			log.WithFields(log.Fields{
 				"partitions": awsPartitions,
 			}).Debug("Search regions for partitions")
@@ -31,15 +43,17 @@ func newAWSCommand() *cobra.Command {
 				log.WithFields(log.Fields{
 					"partitions": awsPartitions,
 				}).Error("Can't find regions for partitions")
-				os.Exit(errorExitCode)
+				return fmt.Errorf("Can't find regions for partitions %v", awsPartitions)
 			}
 
 			log.WithFields(log.Fields{
 				"regions": awsRegions,
 			}).Info("Founds regions")
+			return nil
 		},
-		Run: func(cmd *cobra.Command, args []string) {
+		RunE: func(cmd *cobra.Command, args []string) error {
 			cmd.HelpFunc()(cmd, args)
+			return nil
 		},
 	}
 
@@ -55,8 +69,6 @@ func newAWSCommand() *cobra.Command {
 		internal.GetDefaultKubeconfigPath(),
 		"Path to the kubeconfig to work with")
 
-	AWSCommand.AddCommand(newListCommand())
-	AWSCommand.AddCommand(newUpdateCommand())
-
+	AWSCommand.AddCommand(newListCommand(), newUpdateCommand())
 	return AWSCommand
 }

cmd/aws_list.go

@@ -15,7 +15,7 @@ func newListCommand() *cobra.Command {
 	listCommand := &cobra.Command{
 		Use:   "list",
 		Short: "List all EKS Clusters",
-		Run: func(cmd *cobra.Command, args []string) {
+		RunE: func(cmd *cobra.Command, args []string) error {
 			remoteEKSClusters := internal.GetEKSClusters(awsRegions)
 			log.Info(remoteEKSClusters)
 
@@ -45,6 +45,8 @@ func newListCommand() *cobra.Command {
 			})
 			// render it
 			fmt.Println(tw.Render())
+
+			return nil
 		},
 	}
 

cmd/aws_update.go

@@ -24,7 +24,7 @@ func newUpdateCommand() *cobra.Command {
 	updateCommand := &cobra.Command{
 		Use:   "update",
 		Short: "Update all EKS Clusters",
-		Run: func(cmd *cobra.Command, args []string) {
+		RunE: func(cmd *cobra.Command, args []string) error {
 			fmt.Println(cmd.Short)
 			remoteEKSClusters := internal.GetEKSClusters(awsRegions)
 			log.Info(remoteEKSClusters)
@@ -39,15 +39,14 @@ func newUpdateCommand() *cobra.Command {
 				fmt.Printf("Backup kubeconfig to %v\n", bName)
 				err = copy(kubeconfigPath, bName)
 				if err != nil {
-					fmt.Println(err.Error())
-					return
+					return err
 				}
 			}
 			err := internal.UpdateKubeconfig(remoteEKSClusters, kubeconfigPath, contextName{templateValue: alias})
 			if err != nil {
-				fmt.Println(err.Error())
-				return
+				return err
 			}
+			return nil
 		},
 	}
 	updateCommand.Flags().BoolVar(&backupKubeconfig, "backup-kubeconfig", true, "Backup cubeconfig before update")

cmd/root.go

@@ -15,32 +15,50 @@ import (
 const errorExitCode int = 1
 
 var (
+	loggingLevels map[string]log.Level = map[string]log.Level{
+		"none":  0,
+		"panic": log.PanicLevel,
+		"fatal": log.FatalLevel,
+		"error": log.ErrorLevel,
+		"warn":  log.WarnLevel,
+		"info":  log.InfoLevel,
+		"debug": log.DebugLevel,
+		"trace": log.TraceLevel,
+	}
 	kubeconfigPath string
-	debug          bool
-	rootCmd        = &cobra.Command{
+	logLevel       string
+)
+
+func NewRootCommand() *cobra.Command {
+	rootCmd := &cobra.Command{
 		Use:   "kdiscover",
 		Short: "Discover all EKS clusters on an account.",
 		Long: `kdiscover is a simple utility that can search
 all regions on an AWS account and try to find all EKS clsuters.
 It will try to upgrade the kube-config for each cluster.`,
 
-		PersistentPreRun: func(cmd *cobra.Command, args []string) {
-			if debug {
-				log.SetLevel(log.DebugLevel)
-			} else {
+		PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
+			fmt.Println("root")
+			if logLevel == "none" {
 				log.SetOutput(ioutil.Discard)
+				return nil
+			}
+
+			if v, ok := loggingLevels[logLevel]; ok {
+				log.SetLevel(v)
+				return nil
 			}
+
+			return fmt.Errorf("Can't find logging level %v", logLevel)
 		},
 
-		Run: func(cmd *cobra.Command, args []string) {
+		RunE: func(cmd *cobra.Command, args []string) error {
 			cmd.HelpFunc()(cmd, args)
+			return nil
 		},
 	}
-)
 
-// Execute will create the tree of commands and will start parsing and execution
-func Execute() {
-	rootCmd.PersistentFlags().BoolVar(&debug, "debug", false, "set log level to debug")
+	rootCmd.PersistentFlags().StringVar(&logLevel, "log-level", "none", fmt.Sprintf("Set logging lvl. Supported %v", getAllLogglingLevels()))
 
 	rootCmd.PersistentFlags().StringVar(
 		&kubeconfigPath,
@@ -49,9 +67,24 @@ func Execute() {
 		"Path to the kubeconfig to work with")
 
 	rootCmd.AddCommand(newAWSCommand())
+	return rootCmd
+}
+
+// Execute will create the tree of commands and will start parsing and execution
+func Execute() {
+	rootCmd := NewRootCommand()
 
 	if err := rootCmd.Execute(); err != nil {
 		fmt.Println(err)
 		os.Exit(errorExitCode)
 	}
 }
+
+func getAllLogglingLevels() []string {
+	keys := make([]string, 0, len(loggingLevels))
+	for k := range loggingLevels {
+		keys = append(keys, k)
+	}
+
+	return keys
+}