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/create_image_policy.go

@@ -0,0 +1,182 @@
+/*
+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/spf13/cobra"
+	corev1 "k8s.io/api/core/v1"
+	apimeta "k8s.io/apimachinery/pkg/api/meta"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
+
+	"github.com/fluxcd/flux2/internal/utils"
+	imagev1 "github.com/fluxcd/image-reflector-controller/api/v1alpha1"
+	"github.com/fluxcd/pkg/apis/meta"
+)
+
+var createImagePolicyCmd = &cobra.Command{
+	Use:   "policy <name>",
+	Short: "Create or update an ImagePolicy object",
+	Long: `The create image policy command generates an ImagePolicy resource.
+An ImagePolicy object calculates a "latest image" given an image
+repository and a policy, e.g., semver.
+
+The image that sorts highest according to the policy is recorded in
+the status of the object.`,
+	RunE: createImagePolicyRun}
+
+type imagePolicyFlags struct {
+	imageRef string
+	semver   string
+}
+
+var imagePolicyArgs = imagePolicyFlags{}
+
+func init() {
+	flags := createImagePolicyCmd.Flags()
+	flags.StringVar(&imagePolicyArgs.imageRef, "image-ref", "", "the name of an image repository object")
+	flags.StringVar(&imagePolicyArgs.semver, "semver", "", "a semver range to apply to tags; e.g., '1.x'")
+
+	createImageCmd.AddCommand(createImagePolicyCmd)
+}
+
+func createImagePolicyRun(cmd *cobra.Command, args []string) error {
+	if len(args) < 1 {
+		return fmt.Errorf("ImagePolicy name is required")
+	}
+	objectName := args[0]
+
+	if imagePolicyArgs.imageRef == "" {
+		return fmt.Errorf("the name of an ImageRepository in the namespace is required (--image-ref)")
+	}
+
+	labels, err := parseLabels()
+	if err != nil {
+		return err
+	}
+
+	var policy = imagev1.ImagePolicy{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      objectName,
+			Namespace: namespace,
+			Labels:    labels,
+		},
+		Spec: imagev1.ImagePolicySpec{
+			ImageRepositoryRef: corev1.LocalObjectReference{
+				Name: imagePolicyArgs.imageRef,
+			},
+		},
+	}
+
+	switch {
+	case imagePolicyArgs.semver != "":
+		policy.Spec.Policy.SemVer = &imagev1.SemVerPolicy{
+			Range: imagePolicyArgs.semver,
+		}
+	default:
+		return fmt.Errorf("a policy must be provided with --semver")
+	}
+
+	if export {
+		return printExport(exportImagePolicy(&policy))
+	}
+
+	// I don't need these until attempting to upsert the object, but
+	// for consistency with other create commands, the following are
+	// given a chance to error out before reporting any progress.
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+
+	kubeClient, err := utils.KubeClient(kubeconfig, kubecontext)
+	if err != nil {
+		return err
+	}
+
+	logger.Generatef("generating ImagePolicy")
+	logger.Actionf("applying ImagePolicy")
+	namespacedName, err := upsertImagePolicy(ctx, kubeClient, &policy)
+	if err != nil {
+		return err
+	}
+
+	logger.Waitingf("waiting for ImagePolicy reconciliation")
+	if err := wait.PollImmediate(pollInterval, timeout,
+		isImagePolicyReady(ctx, kubeClient, namespacedName, &policy)); err != nil {
+		return err
+	}
+	logger.Successf("ImagePolicy reconciliation completed")
+
+	return nil
+}
+
+func upsertImagePolicy(ctx context.Context, kubeClient client.Client, policy *imagev1.ImagePolicy) (types.NamespacedName, error) {
+	nsname := types.NamespacedName{
+		Namespace: policy.GetNamespace(),
+		Name:      policy.GetName(),
+	}
+
+	var existing imagev1.ImagePolicy
+	existing.SetName(nsname.Name)
+	existing.SetNamespace(nsname.Namespace)
+	op, err := controllerutil.CreateOrUpdate(ctx, kubeClient, &existing, func() error {
+		existing.Spec = policy.Spec
+		existing.SetLabels(policy.Labels)
+		return nil
+	})
+	if err != nil {
+		return nsname, err
+	}
+
+	switch op {
+	case controllerutil.OperationResultCreated:
+		logger.Successf("ImagePolicy created")
+	case controllerutil.OperationResultUpdated:
+		logger.Successf("ImagePolicy updated")
+	}
+	return nsname, nil
+}
+
+func isImagePolicyReady(ctx context.Context, kubeClient client.Client,
+	namespacedName types.NamespacedName, policy *imagev1.ImagePolicy) wait.ConditionFunc {
+	return func() (bool, error) {
+		err := kubeClient.Get(ctx, namespacedName, policy)
+		if err != nil {
+			return false, err
+		}
+
+		// Confirm the state we are observing is for the current generation
+		if policy.Generation != policy.Status.ObservedGeneration {
+			return false, nil
+		}
+
+		if c := apimeta.FindStatusCondition(policy.Status.Conditions, meta.ReadyCondition); c != nil {
+			switch c.Status {
+			case metav1.ConditionTrue:
+				return true, nil
+			case metav1.ConditionFalse:
+				return false, fmt.Errorf(c.Message)
+			}
+		}
+		return false, nil
+	}
+}