Merge pull request #21 from Ladicle/msg-and-desc

Provide readable error and help messages

README.md

@@ -1,6 +1,6 @@
 # kubectl-bindrole
 
-Summarize RBAC roles tied to the given subject.
+Summarize RBAC roles for the specified subject (ServiceAccount, User and Group).
 
 ![screenshot](./img/screenshot.png)
 
@@ -11,8 +11,7 @@ Summarize RBAC roles tied to the given subject.
 bindrole supports [homebrew](https://docs.brew.sh/Installation) :beer:
 
 ```
-brew tap Ladicle/kubectl-bindrole
-brew install kubectl-bindrole
+brew install Ladicle/kubectl-bindrole/kubectl-bindrole
 ```
 
 ### for other devices
@@ -24,23 +23,31 @@ You can also download this repository and install it using Makefile.
 
 ```bash
 $ kubectl bindrole -h  # or kubectl-bindrole -h
-Summarize RBAC roles tied to the given subject
+Summarize RBAC roles for the specified subject
+
+Usage:
+  kubectl bindrole [options] <SubjectName>
 
 Examples:
   # Summarize roles tied to the "ci-bot" ServiceAccount.
-  kubectl-bindrole ci-bot
+  kubectl bindrole ci-bot
 
   # Summarize roles tied to the "developer" Group.
-  kubectl-bindrole developer -k Group
+  kubectl bindrole -k Group developer
 
-Options:
-  -k, --subject-kind='ServiceAccount': subject kind (available: ServiceAccount, Group or User)
-      --version=false: version for kubectl-bindrole
+SubjectKinds:
+  - ServiceAccount (default)
+  - User
+  - Group
 
-Usage:
-  kubectl-bindrole <SubjectName> [options]
+Options:
+  -h, --help                   Display this help message
+  -n, --namespace string       Change the namespace scope for this CLI request
+  -k, --subject-kind string    Set SubjectKind to summarize (default: ServiceAccount)
+  -o, --options                List of all options for this command
+      --version                Show version for this command
 
-Use "kubectl-bindrole options" for a list of global command-line options (applies to all commands).
+Use "kubectl bindrole --options" for a list of all options (applies to this command).
 ```
 
 This command supports both kubectl-plugin mode and standalone mode.

cmd/cmd.go

@@ -3,18 +3,22 @@ package cmd
 import (
 	"errors"
 	"fmt"
+	"os"
 
 	// Initialize all known client auth plugins.
 	_ "k8s.io/client-go/plugin/pkg/client/auth"
 
+	"github.com/logrusorgru/aurora"
 	"github.com/spf13/cobra"
 	rbacv1 "k8s.io/api/rbac/v1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/cli-runtime/pkg/genericclioptions"
 	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 	"k8s.io/kubectl/pkg/util/templates"
 
 	"github.com/Ladicle/kubectl-bindrole/pkg/explorer"
+	brcmdutil "github.com/Ladicle/kubectl-bindrole/pkg/util/cmd"
 	"github.com/Ladicle/kubectl-bindrole/pkg/util/printer"
 	"github.com/Ladicle/kubectl-bindrole/pkg/util/subject"
 )
@@ -24,35 +28,44 @@ var (
 	command string
 	version string
 	commit  string
+
+	bindroleExample = fmt.Sprintf(`%v
+kubectl bindrole ci-bot
+
+%v
+kubectl bindrole -k Group developer`,
+		aurora.BrightBlack("# Summarize roles tied to the \"ci-bot\" ServiceAccount."),
+		aurora.BrightBlack("# Summarize roles tied to the \"developer\" Group."))
 )
 
 type Option struct {
-	SubjectKind string
-	SubjectName string
+	SubjectKind    string
+	SubjectName    string
+	ShowOptionFlag bool
 
 	f cmdutil.Factory
 }
 
 func NewBindroleCmd() *cobra.Command {
 	opt := Option{}
 	cmd := &cobra.Command{
-		Use:                   fmt.Sprintf("%s <SubjectName>", command),
-		Version:               fmt.Sprintf("%v @%v", version, commit),
+		Use: fmt.Sprintf("bindrole [options] <%v>",
+			aurora.Yellow("SubjectName")),
+		Version:               version,
 		DisableFlagsInUseLine: true,
-		Short:                 "Summarize RBAC roles tied to the given subject",
-		Long:                  templates.LongDesc("Summarize RBAC roles tied to the given subject"),
-		Example: templates.Examples(fmt.Sprintf(`# Summarize roles tied to the "ci-bot" ServiceAccount.
-%s ci-bot
-
-# Summarize roles tied to the "developer" Group.
-%s developer -k Group`, command, command)),
+		SilenceUsage:          true,
+		SilenceErrors:         true,
+		Short:                 "Summarize RBAC roles for the specified subject",
+		Long:                  "Summarize RBAC roles for the specified subject",
+		Example:               templates.Examples(bindroleExample),
 		Run: func(cmd *cobra.Command, args []string) {
-			cmdutil.CheckErr(opt.Validate(cmd, args))
-			cmdutil.CheckErr(opt.Run())
+			brcmdutil.CheckErr(opt.Validate(cmd, args))
+			brcmdutil.CheckErr(opt.Run())
 		},
 	}
 
-	templates.ActsAsRootCommand(cmd, []string{"options"})
+	cmd.SetVersionTemplate(brcmdutil.VersionTemplate)
+	cmd.SetUsageTemplate(brcmdutil.UsageTemplate)
 
 	fsets := cmd.PersistentFlags()
 	cfgFlags := genericclioptions.NewConfigFlags(true)
@@ -62,17 +75,31 @@ func NewBindroleCmd() *cobra.Command {
 
 	opt.f = cmdutil.NewFactory(matchVersionFlags)
 
-	cmd.Flags().StringVarP(&opt.SubjectKind, "subject-kind", "k", subject.KindSA,
-		fmt.Sprintf("subject kind (available: %s, %s or %s)", subject.KindSA, subject.KindGroup, subject.KindUser))
+	cmd.Flags().StringVarP(&opt.SubjectKind, "subject-kind", "k", subject.KindSA, "Set SubjectKind to summarize")
+	cmd.Flags().BoolVarP(&opt.ShowOptionFlag, "options", "o", false, "List of all options for this command")
 
 	return cmd
 }
 
 func (o *Option) Validate(cmd *cobra.Command, args []string) error {
+	if o.ShowOptionFlag {
+		cmd.SetUsageTemplate(brcmdutil.OptionTemplate)
+		fmt.Println(cmd.UsageString())
+		os.Exit(0)
+	}
+
 	if len(args) == 0 {
-		return errors.New("subject name is required")
+		return errors.New(fmt.Sprintf("<%v> is required argument",
+			aurora.Cyan("SubjectName").Bold()))
 	}
 	o.SubjectName = args[0]
+
+	switch o.SubjectKind {
+	case subject.KindGroup, subject.KindSA, subject.KindUser:
+	default:
+		return errors.New(fmt.Sprintf("\"%v\" is unknown SubjectKind",
+			aurora.Cyan(o.SubjectKind).Bold()))
+	}
 	return nil
 }
 
@@ -106,14 +133,20 @@ func (o *Option) Run() error {
 	}
 
 	pp := printer.DefaultPrettyPrinter()
-	pp.PrintSubject(sub)
+
 	if sub.Kind == subject.KindSA {
 		sa, err := client.CoreV1().ServiceAccounts(sub.Namespace).
 			Get(sub.Name, metav1.GetOptions{})
-		if err != nil {
+		if apierrors.IsNotFound(err) {
+			return errors.New(fmt.Sprintf("ServiceAccount \"%v\" not found",
+				aurora.Cyan(fmt.Sprintf("%v/%v", sub.Namespace, sub.Name)).Bold()))
+		} else if err != nil {
 			return err
 		}
+		pp.PrintSubject(sub)
 		pp.PrintSA(sa)
+	} else {
+		pp.PrintSubject(sub)
 	}
 
 	pp.BlankLine()

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/mattn/go-runewidth v0.0.4 // indirect
 	github.com/olekukonko/tablewriter v0.0.1
 	github.com/spf13/cobra v0.0.5
+	github.com/spf13/pflag v1.0.5
 	k8s.io/api v0.17.4
 	k8s.io/apimachinery v0.17.4
 	k8s.io/cli-runtime v0.17.4

main.go

@@ -1,15 +1,18 @@
 package main
 
 import (
-	"fmt"
-	"os"
+	"github.com/spf13/pflag"
 
 	"github.com/Ladicle/kubectl-bindrole/cmd"
+	cmdutil "github.com/Ladicle/kubectl-bindrole/pkg/util/cmd"
 )
 
+func init() {
+	flags := pflag.NewFlagSet("kubectl-bindrole", pflag.ExitOnError)
+	pflag.CommandLine = flags
+}
+
 func main() {
 	command := cmd.NewBindroleCmd()
-	if err := command.Execute(); err != nil {
-		fmt.Fprintf(os.Stderr, "Error: %v", err)
-	}
+	cmdutil.CheckErr(command.Execute())
 }

pkg/util/cmd/error.go

@@ -0,0 +1,17 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/logrusorgru/aurora"
+)
+
+func CheckErr(err error) {
+	if err == nil {
+		return
+	}
+	fmt.Fprintf(os.Stderr, " %v Error: %v.\n", aurora.Red(">"), err)
+	fmt.Fprintf(os.Stderr, " %v Run %v command for the usage.\n", aurora.Red(">"), aurora.Yellow("kubectl bindrole -h"))
+	os.Exit(1)
+}

pkg/util/cmd/usage.go

@@ -0,0 +1,47 @@
+package cmd
+
+import (
+	"fmt"
+
+	"github.com/logrusorgru/aurora"
+)
+
+var UsageTemplate = fmt.Sprintf(`%v:{{if .Runnable}}
+  kubectl {{.UseLine}}{{end}}{{if .HasAvailableSubCommands}}
+  {{.CommandPath}} [command]{{end}}{{if gt (len .Aliases) 0}}
+
+%v:
+  {{.NameAndAliases}}{{end}}{{if .HasExample}}
+
+%v:
+{{.Example}}{{end}}{{if .HasAvailableSubCommands}}
+
+Available Commands:{{range .Commands}}{{if (or .IsAvailableCommand (eq .Name "help"))}}
+  {{rpad .Name .NamePadding }} {{.Short}}{{end}}{{end}}{{end}}
+
+%v:
+  - ServiceAccount (default)
+  - User
+  - Group
+
+%v:
+  -h, --help                   Display this help message
+  -n, --namespace string       Change the namespace scope for this CLI request
+  -k, --subject-kind string    Set SubjectKind to summarize (default: ServiceAccount)
+  -o, --options                List of all options for this command
+      --version                Show version for this command
+
+Use "kubectl bindrole --options" for a list of all options (applies to this command).
+`,
+	aurora.Cyan("Usage"),
+	aurora.Cyan("Aliases"),
+	aurora.Cyan("Examples"),
+	aurora.Cyan("SubjectKinds"),
+	aurora.Cyan("Options"))
+
+var OptionTemplate = `The following options can be passed to this command:
+
+{{if .HasAvailableLocalFlags}}{{.LocalFlags.FlagUsages | trimTrailingWhitespaces}}{{end}}`
+
+var VersionTemplate = fmt.Sprintf(` %v {{.Name}} version {{.Version}}
+`, aurora.Yellow(">"))