feature: Initialize kn admin plugin

OWNERS

@@ -4,6 +4,7 @@ approvers:
 - rhuss
 - maximilien
 - navidshaikh
+- zhanggbj
 # TOC members as a fallback
 - mattmoor
 - evankanderson

plugins/admin/README.adoc

@@ -0,0 +1,124 @@
+## kn-admin
+
+A kn plugin for Knative cluster management.
+
+`kn hello` prints out a friendly message to the user.
+
+### Description
+
+This kn-admin plugin is designed to help administrators and operators better manage a Knative platform installation with kn CLI.
+The plugin’s main objective is to make administration and operation workflows easier, for instance by making it easy to accomplish
+tasks such as feature flags enablement or disablement with one command, instead of many manual steps like modifying ConfigMaps or yaml files.
+
+### Usage
+
+----
+A plugin of kn client to manage Knative for administrators.
+
+For example:
+kn admin domain set - to set Knative route domain
+kn admin private-registry enable - to enable deployment from the private registry
+
+Usage:
+  kn admin [command]
+
+Available Commands:
+  domain           Manage route domain
+  help             Help about any command
+  private-registry Manage private-registry
+
+Flags:
+      --config string   config file (default is $HOME/.config/kn/plugins/kn-admin.yaml)
+  -h, --help            help for admin
+  -t, --toggle          Help message for toggle
+
+Use "admin [command] --help" for more information about a command.
+----
+
+#### `kn admin domain`
+
+----
+Set default route domain or route domain for Service with selectors. For example:
+
+kn admin domain set - to set Knative route domain
+
+Usage:
+  kn admin domain [flags]
+  kn admin domain [command]
+
+Available Commands:
+  set         set route domain
+
+Flags:
+  -h, --help   help for domain
+
+Global Flags:
+      --config string   config file (default is $HOME/.config/kn/plugins/admin.yaml)
+
+Use "admin domain [command] --help" for more information about a command.
+
+----
+
+#### `kn admin private-registry`
+
+----
+Manage Service deployment from a private registry
+For example:
+
+kn admin private-registry enable \
+  --secret-name=[SECRET_NAME]
+  --docker-server=[PRIVATE_REGISTRY_SERVER_URL] \
+  --docker-email=[PRIVATE_REGISTRY_EMAIL] \
+  --docker-username=[PRIVATE_REGISTRY_USER] \
+  --docker-password=[PRIVATE_REGISTRY_PASSWORD]
+
+Usage:
+  kn admin private-registry [command]
+
+Available Commands:
+  enable      enable Service deployment from a private registry
+
+Flags:
+  -h, --help   help for private-registry
+
+Global Flags:
+      --config string   config file (default is $HOME/.config/kn/plugins/admin.yaml)
+
+Use "admin private-registry [command] --help" for more information about a command.
+
+----
+
+### Examples
+
+#### As a Knative administrator, I want to update Knative route domain with my custom domain.
+
+
+.Update the default route domain if --selector no specified
+====
+----
+$ kn admin domain set --custom-domain mydomain.com
+Updated Knative route domain mydomain.com
+----
+====
+
+.Update a custom domain with --selector and Service with a label app=v1 will use test.com
+====
+----
+$ kn admin domain set --custom-domain test.com --selector app=v1
+Updated Knative route domain test.com
+----
+====
+
+#### As a Knative administrator, I want to enable deploying from private registry.
+
+.Enable a private registry with given credentials for Service creation
+=====
+-----
+$ kn admin private-registry enable \
+  --secret-name=[SECRET_NAME]
+  --docker-server=[PRIVATE_REGISTRY_SERVER_URL] \
+  --docker-email=[PRIVATE_REGISTRY_EMAIL] \
+  --docker-username=[PRIVATE_REGISTRY_USER] \
+  --docker-password=[PRIVATE_REGISTRY_PASSWORD]
+-----
+=====

plugins/admin/cmd/kn-admin.go

@@ -0,0 +1,28 @@
+// Copyright © 2020 The Knative Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"knative.dev/client-contrib/plugins/admin/core"
+)
+
+func main() {
+	if err := core.NewAdminCommand().Execute(); err != nil {
+		fmt.Println("failed to execute admin command:", err)
+		os.Exit(1)
+	}
+}

plugins/admin/core/root.go

@@ -0,0 +1,100 @@
+// Copyright © 2020 The Knative Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package core
+
+import (
+	"fmt"
+	"os"
+
+	"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"
+	private_registry "knative.dev/client-contrib/plugins/admin/pkg/command/registry"
+)
+
+var cfgFile string
+
+// rootCmd represents the base command when called without any subcommands
+
+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)
+	}
+
+	rootCmd := &cobra.Command{
+		Use:   "kn\u00A0admin",
+		Short: "A plugin of kn client to manage Knative",
+		Long: `kn admin: a plugin of kn client to manage Knative for administrators.
+
+For example:
+kn admin domain set - to set Knative route domain
+kn admin registry add - to add registry with credentials
+`,
+	}
+	cobra.OnInitialize(initConfig)
+	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.config/kn/plugins/admin.yaml)")
+	rootCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
+	//
+	rootCmd.AddCommand(domain.NewDomainCmd(p))
+	rootCmd.AddCommand(private_registry.NewPrivateRegistryCmd(p))
+	rootCmd.AddCommand(command.NewVersionCommand())
+	return rootCmd
+}
+
+// initConfig reads in config file and ENV variables if set.
+func initConfig() {
+	if cfgFile != "" {
+		// Use config file from the flag.
+		viper.SetConfigFile(cfgFile)
+	} else {
+		// Find home directory.
+		home, err := homedir.Dir()
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+
+		// Search config in home directory with name ".admin" (without extension).
+		viper.AddConfigPath(home)
+		viper.SetConfigName(".admin")
+	}
+
+	viper.AutomaticEnv() // read in environment variables that match
+
+	// If a config file is found, read it in.
+	if err := viper.ReadInConfig(); err == nil {
+		fmt.Println("Using config file:", viper.ConfigFileUsed())
+	}
+}

plugins/admin/go.mod

@@ -0,0 +1,21 @@
+module knative.dev/client-contrib/plugins/admin
+
+go 1.13
+
+require (
+	github.com/google/go-cmp v0.3.1 // indirect
+	github.com/googleapis/gnostic v0.2.2 // indirect
+	github.com/imdario/mergo v0.3.8 // indirect
+	github.com/mitchellh/go-homedir v1.1.0
+	github.com/pkg/errors v0.8.1 // indirect
+	github.com/spf13/cobra v0.0.5
+	github.com/spf13/viper v1.6.2
+	golang.org/x/crypto v0.0.0-20191206172530-e9b2fee46413 // indirect
+	golang.org/x/sys v0.0.0-20191010194322-b09406accb47 // indirect
+	google.golang.org/appengine v1.6.2 // indirect
+	gotest.tools v2.2.0+incompatible
+	k8s.io/api v0.17.3
+	k8s.io/apimachinery v0.17.3
+	k8s.io/client-go v0.17.0
+	k8s.io/utils v0.0.0-20200124190032-861946025e34 // indirect
+)