[kn-admin]Refine k8s client and flag check (#25)

- Refine k8s client init and align with kn client
- Add preRunE to check flag values
- Add default help

plugins/admin/core/root.go

@@ -21,8 +21,6 @@ import (
 	homedir "github.com/mitchellh/go-homedir"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
-	"k8s.io/client-go/kubernetes"
-	"k8s.io/client-go/tools/clientcmd"
 	"knative.dev/client-contrib/plugins/admin/pkg"
 	"knative.dev/client-contrib/plugins/admin/pkg/command"
 	"knative.dev/client-contrib/plugins/admin/pkg/command/domain"
@@ -35,23 +33,7 @@ var cfgFile string
 
 func NewAdminCommand(params ...pkg.AdminParams) *cobra.Command {
 	p := &pkg.AdminParams{}
-	kubeConfig := os.Getenv("KUBECONFIG")
-	if kubeConfig == "" {
-		fmt.Println("cannot get cluster kube config, please export environment variable KUBECONFIG")
-		os.Exit(1)
-	}
-
-	cfg, err := clientcmd.BuildConfigFromFlags("", kubeConfig)
-	if err != nil {
-		fmt.Println("failed to build config:", err)
-		os.Exit(1)
-	}
-
-	p.ClientSet, err = kubernetes.NewForConfig(cfg)
-	if err != nil {
-		fmt.Println("failed to create client:", err)
-		os.Exit(1)
-	}
+	p.Initialize()
 
 	rootCmd := &cobra.Command{
 		Use:   "kn\u00A0admin",
@@ -70,6 +52,9 @@ kn admin registry add - to add registry with credentials
 	rootCmd.AddCommand(domain.NewDomainCmd(p))
 	rootCmd.AddCommand(private_registry.NewPrivateRegistryCmd(p))
 	rootCmd.AddCommand(command.NewVersionCommand())
+
+	// Add default help page if there's unknown command
+	rootCmd.InitDefaultHelpCmd()
 	return rootCmd
 }
 

plugins/admin/pkg/command/domain/domain.go

@@ -15,8 +15,6 @@
 package domain
 
 import (
-	"fmt"
-
 	"github.com/spf13/cobra"
 	"knative.dev/client-contrib/plugins/admin/pkg"
 )
@@ -26,13 +24,11 @@ func NewDomainCmd(p *pkg.AdminParams) *cobra.Command {
 	var domainCmd = &cobra.Command{
 		Use:   "domain",
 		Short: "Manage route domain",
-		Long: `Set default route domain or route domain for Service with selectors. For example:
+		Long: `Set default route domain or custom route domain for Service with selectors. For example:
 
 kn admin domain set - to set Knative route domain`,
-		Run: func(cmd *cobra.Command, args []string) {
-			fmt.Println("domain called")
-		},
 	}
 	domainCmd.AddCommand(NewDomainSetCommand(p))
+	domainCmd.InitDefaultHelpCmd()
 	return domainCmd
 }

plugins/admin/pkg/command/domain/set.go

@@ -15,6 +15,7 @@
 package domain
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"strings"
@@ -45,6 +46,12 @@ kn admin domain set --custom-domain mydomain.com
 # To set a route domain for service having label app=v1
 kn admin domain set --custom-domain mydomain.com --selector app=v1
 `,
+		PreRunE: func(cmd *cobra.Command, args []string) error {
+			if domain == "" {
+				return errors.New("'domain set' requires the route name to run provided with the --custom-domain option")
+			}
+			return nil
+		},
 		Run: func(cmd *cobra.Command, args []string) {
 			currentCm := &corev1.ConfigMap{}
 			currentCm, err := p.ClientSet.CoreV1().ConfigMaps("knative-serving").Get("config-domain", metav1.GetOptions{})
@@ -94,7 +101,11 @@ kn admin domain set --custom-domain mydomain.com --selector app=v1
 	}
 
 	domainSetCommand.Flags().StringVarP(&domain, "custom-domain", "d", "", "Desired custom domain")
+	domainSetCommand.MarkFlagRequired("custom-domain")
 	domainSetCommand.Flags().StringSliceVar(&selector, "selector", nil, "Domain selector")
+
+	domainSetCommand.InitDefaultHelpFlag()
+
 	return domainSetCommand
 }
 

plugins/admin/pkg/command/registry/add.go

@@ -15,6 +15,7 @@
 package registry
 
 import (
+	"errors"
 	"fmt"
 	"os"
 
@@ -28,14 +29,14 @@ import (
 )
 
 type prcmdFlags struct {
-	DockerServer   string
-	SecretName     string
-	DockerEmail    string
-	DockerUsername string
-	DockerPassword string
+	Server     string
+	SecretName string
+	Email      string
+	Username   string
+	Password   string
 }
 
-type DockerRegistry struct {
+type Registry struct {
 	Auths Auths `json:"auths"`
 }
 type RegistryCred struct {
@@ -44,9 +45,6 @@ type RegistryCred struct {
 	Email    string `json:"Email"`
 }
 
-//type Auths struct {
-//	RegistryCred RegistryCred `json:"us.icr.io"`
-//}
 type Auths map[string]RegistryCred
 
 //
@@ -69,13 +67,25 @@ kn admin registry add \
   --email=[REGISTRY_EMAIL] \
   --username=[REGISTRY_USER] \
   --password=[REGISTRY_PASSWORD]`,
+		PreRunE: func(cmd *cobra.Command, args []string) error {
+			if prflags.Username == "" {
+				return errors.New("'registry add' requires the registry user name to run provided with the --username option")
+			}
+			if prflags.Password == "" {
+				return errors.New("'registry add' requires the registry password to run provided with the --password option")
+			}
+			if prflags.Server == "" {
+				return errors.New("'registry add' requires the registry server to run provided with the --server option")
+			}
+			return nil
+		},
 		Run: func(cmd *cobra.Command, args []string) {
-			dockerCfg := DockerRegistry{
+			dockerCfg := Registry{
 				Auths: Auths{
-					prflags.DockerServer: RegistryCred{
-						Username: prflags.DockerUsername,
-						Password: prflags.DockerPassword,
-						Email:    prflags.DockerEmail,
+					prflags.Server: RegistryCred{
+						Username: prflags.Username,
+						Password: prflags.Password,
+						Email:    prflags.Email,
 					},
 				},
 			}
@@ -96,8 +106,8 @@ kn admin registry add \
 				},
 				Type: corev1.SecretTypeDockerConfigJson,
 				ObjectMeta: metav1.ObjectMeta{
-					Name:      prflags.SecretName,
-					Namespace: "default",
+					GenerateName: fmt.Sprintf("%s-", prflags.SecretName),
+					Namespace:    "default",
 				},
 				Data: secretData,
 			}
@@ -120,15 +130,19 @@ kn admin registry add \
 				os.Exit(1)
 			}
 
-			fmt.Printf("Private registry %s added for default Service Account\n", prflags.DockerServer)
+			fmt.Printf("Private registry %s added for default Service Account\n", prflags.Server)
 		},
 	}
 
-	prAddCmd.Flags().StringVar(&prflags.SecretName, "secret-name", "", "Registry Secret Name")
-	prAddCmd.Flags().StringVar(&prflags.DockerServer, "server", "", "Registry Address")
-	prAddCmd.Flags().StringVar(&prflags.DockerEmail, "email", "", "Registry Email")
-	prAddCmd.Flags().StringVar(&prflags.DockerUsername, "username", "", "Registry Username")
-	prAddCmd.Flags().StringVar(&prflags.DockerPassword, "password", "", "Registry Email")
+	prAddCmd.Flags().StringVar(&prflags.SecretName, "secret-name", "secret-registry", "Registry Secret Name")
+	prAddCmd.Flags().StringVar(&prflags.Server, "server", "", "Registry Address")
+	prAddCmd.MarkFlagRequired("server")
+	prAddCmd.Flags().StringVar(&prflags.Email, "email", "[email protected]", "Registry Email")
+	prAddCmd.Flags().StringVar(&prflags.Username, "username", "", "Registry Username")
+	prAddCmd.MarkFlagRequired("username")
+	prAddCmd.Flags().StringVar(&prflags.Password, "password", "", "Registry Password")
+	prAddCmd.MarkFlagRequired("password")
 
+	prAddCmd.InitDefaultHelpFlag()
 	return prAddCmd
 }

plugins/admin/pkg/command/registry/registry.go

@@ -35,5 +35,6 @@ kn admin registry add \
   --password=[REGISTRY_PASSWORD]`,
 	}
 	privateRegistryCmd.AddCommand(NewPrAddCommand(p))
+	privateRegistryCmd.InitDefaultHelpCmd()
 	return privateRegistryCmd
 }

plugins/admin/pkg/types.go

@@ -15,7 +15,12 @@
 package pkg
 
 import (
+	"fmt"
+	"os"
+	"path/filepath"
+
 	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/clientcmd"
 )
 
@@ -24,3 +29,63 @@ type AdminParams struct {
 	ClientConfig clientcmd.ClientConfig
 	ClientSet    *kubernetes.Clientset
 }
+
+func (params *AdminParams) Initialize() error {
+	if params.ClientSet == nil {
+		restConfig, err := params.RestConfig()
+		if err != nil {
+			return err
+		}
+
+		params.ClientSet, err = kubernetes.NewForConfig(restConfig)
+		if err != nil {
+			fmt.Println("failed to create client:", err)
+			os.Exit(1)
+		}
+	}
+	return nil
+}
+
+// RestConfig returns REST config, which can be to use to create specific clientset
+func (params *AdminParams) RestConfig() (*rest.Config, error) {
+	var err error
+
+	if params.ClientConfig == nil {
+		params.ClientConfig, err = params.GetClientConfig()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	config, err := params.ClientConfig.ClientConfig()
+	if err != nil {
+		return nil, err
+	}
+
+	return config, nil
+}
+
+// GetClientConfig gets ClientConfig from KubeCfgPath
+func (params *AdminParams) GetClientConfig() (clientcmd.ClientConfig, error) {
+	loadingRules := clientcmd.NewDefaultClientConfigLoadingRules()
+	if len(params.KubeCfgPath) == 0 {
+		return clientcmd.NewNonInteractiveDeferredLoadingClientConfig(loadingRules, &clientcmd.ConfigOverrides{}), nil
+	}
+
+	_, err := os.Stat(params.KubeCfgPath)
+	if err == nil {
+		loadingRules.ExplicitPath = params.KubeCfgPath
+		return clientcmd.NewNonInteractiveDeferredLoadingClientConfig(loadingRules, &clientcmd.ConfigOverrides{}), nil
+	}
+
+	if !os.IsNotExist(err) {
+		return nil, err
+	}
+
+	paths := filepath.SplitList(params.KubeCfgPath)
+	if len(paths) > 1 {
+		return nil, fmt.Errorf("Can not find config file. '%s' looks like a path. "+
+			"Please use the env var KUBECONFIG if you want to check for multiple configuration files", params.KubeCfgPath)
+	}
+	return nil, fmt.Errorf("Config file '%s' can not be found", params.KubeCfgPath)
+}