Rename "auto" subcommands to "image"

This means all the sub-subcommands can drop the `image-` prefix,
making them shorter and more fluent.

E.g.,

    flux create image policy

rather than

    flux create auto image-policy

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

cmd/flux/export_image_repository.go

@@ -0,0 +1,70 @@
+/*
+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 (
+	"github.com/spf13/cobra"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
+	imagev1 "github.com/fluxcd/image-reflector-controller/api/v1alpha1"
+)
+
+var exportImageRepositoryCmd = &cobra.Command{
+	Use:   "repository [name]",
+	Short: "Export ImageRepository resources in YAML format",
+	Long:  "The export image repository command exports one or all ImageRepository resources in YAML format.",
+	Example: `  # Export all ImageRepository resources
+  flux export image repository --all > image-repositories.yaml
+
+  # Export a specific ImageRepository resource
+  flux export image repository alpine > alpine.yaml
+`,
+	RunE: exportCommand{
+		object: imageRepositoryAdapter{&imagev1.ImageRepository{}},
+		list:   imageRepositoryListAdapter{&imagev1.ImageRepositoryList{}},
+	}.run,
+}
+
+func init() {
+	exportImageCmd.AddCommand(exportImageRepositoryCmd)
+}
+
+func exportImageRepository(repo *imagev1.ImageRepository) interface{} {
+	gvk := imagev1.GroupVersion.WithKind(imagev1.ImageRepositoryKind)
+	export := imagev1.ImageRepository{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       gvk.Kind,
+			APIVersion: gvk.GroupVersion().String(),
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:        repo.Name,
+			Namespace:   repo.Namespace,
+			Labels:      repo.Labels,
+			Annotations: repo.Annotations,
+		},
+		Spec: repo.Spec,
+	}
+	return export
+}
+
+func (ex imageRepositoryAdapter) export() interface{} {
+	return exportImageRepository(ex.ImageRepository)
+}
+
+func (ex imageRepositoryListAdapter) exportItem(i int) interface{} {
+	return exportImageRepository(&ex.ImageRepositoryList.Items[i])
+}