Add subcommands for image-repository

This adds all the standard subcommands for the ImageRepository type.

Following `source`, I have put them under a namespace: `auto`,
referring to automation.

NB For `create` I use controllerutil.CreateOrUpdate, which looks to me
like a slightly more rounded version of the upsert* funcs.

Signed-off-by: Michael Bridgen <michael@weave.works>

cmd/flux/delete_auto_imagerepository.go

@@ -0,0 +1,88 @@
+/*
+Copyright 2020 The Flux 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 (
+	"context"
+	"fmt"
+
+	"github.com/manifoldco/promptui"
+	"github.com/spf13/cobra"
+	"k8s.io/apimachinery/pkg/types"
+
+	"github.com/fluxcd/flux2/internal/utils"
+	imagev1 "github.com/fluxcd/image-reflector-controller/api/v1alpha1"
+)
+
+var deleteImageRepositoryCmd = &cobra.Command{
+	Use:   "image-repository [name]",
+	Short: "Delete an ImageRepository object",
+	Long:  "The delete auto image-repository command deletes the given ImageRepository from the cluster.",
+	Example: `  # Delete an image repository
+  flux delete auto image-repository alpine
+`,
+	RunE: deleteImageRepositoryRun,
+}
+
+func init() {
+	deleteAutoCmd.AddCommand(deleteImageRepositoryCmd)
+}
+
+func deleteImageRepositoryRun(cmd *cobra.Command, args []string) error {
+	if len(args) < 1 {
+		return fmt.Errorf("image repository name is required")
+	}
+	name := args[0]
+
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+
+	kubeClient, err := utils.KubeClient(kubeconfig, kubecontext)
+	if err != nil {
+		return err
+	}
+
+	namespacedName := types.NamespacedName{
+		Namespace: namespace,
+		Name:      name,
+	}
+
+	var repo imagev1.ImageRepository
+	err = kubeClient.Get(ctx, namespacedName, &repo)
+	if err != nil {
+		return err
+	}
+
+	if !deleteSilent {
+		prompt := promptui.Prompt{
+			Label:     "Are you sure you want to delete this image repository",
+			IsConfirm: true,
+		}
+		if _, err := prompt.Run(); err != nil {
+			return fmt.Errorf("aborting")
+		}
+	}
+
+	logger.Actionf("deleting image repository %s in %s namespace", name, namespace)
+	err = kubeClient.Delete(ctx, &repo)
+	if err != nil {
+		return err
+	}
+	logger.Successf("image repository deleted")
+
+	return nil
+}