refactor: use cli-skeleton for commands

.gitignore

@@ -22,3 +22,5 @@ validation/*
 
 # .env files
 .env*
+
+docker-image-labeler

README.md

@@ -29,3 +29,16 @@ In addition, builds can be performed in an isolated Docker container:
 ```shell
 make build-docker-image build-in-docker
 ```
+
+## Usage
+
+```shell
+# pull an image
+docker image pull mysql:8
+
+# add a label
+./docker-image-labeler relabel --label=mysql.version=8 mysql:8
+
+# remove the label
+./docker-image-labeler relabel --remove-label=mysql.version mysql:8
+```

commands/relabel.go

@@ -0,0 +1,308 @@
+package commands
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/buildpacks/imgutil/local"
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/client"
+	dockercli "github.com/docker/docker/client"
+	"github.com/docker/docker/errdefs"
+	"github.com/josegonzalez/cli-skeleton/command"
+	"github.com/posener/complete"
+	flag "github.com/spf13/pflag"
+)
+
+const APIVERSION = "1.25"
+
+type RelabelCommand struct {
+	command.Meta
+
+	addLabels    []string
+	removeLabels []string
+}
+
+func (c *RelabelCommand) Name() string {
+	return "relabel"
+}
+
+func (c *RelabelCommand) Synopsis() string {
+	return "Re-labels a docker image"
+}
+
+func (c *RelabelCommand) Help() string {
+	return command.CommandHelp(c)
+}
+
+func (c *RelabelCommand) Examples() map[string]string {
+	appName := os.Getenv("CLI_APP_NAME")
+	return map[string]string{
+		"Add a label":            fmt.Sprintf("%s %s --label=label.key=label.value docker/image:latest", appName, c.Name()),
+		"Remove a label":         fmt.Sprintf("%s %s --remove-label=label.key=label.value docker/image:latest", appName, c.Name()),
+		"Add and remove a label": fmt.Sprintf("%s %s --label=new=value --remove-label=old=value docker/image:latest", appName, c.Name()),
+	}
+}
+
+func (c *RelabelCommand) Arguments() []command.Argument {
+	args := []command.Argument{}
+	args = append(args, command.Argument{
+		Name:        "image-name",
+		Description: "name of image to manipulate",
+		Optional:    false,
+		Type:        command.ArgumentString,
+	})
+	return args
+}
+
+func (c *RelabelCommand) AutocompleteArgs() complete.Predictor {
+	return complete.PredictNothing
+}
+
+func (c *RelabelCommand) ParsedArguments(args []string) (map[string]command.Argument, error) {
+	return command.ParseArguments(args, c.Arguments())
+}
+
+func (c *RelabelCommand) FlagSet() *flag.FlagSet {
+	f := c.Meta.FlagSet(c.Name(), command.FlagSetClient)
+	f.StringSliceVar(&c.addLabels, "label", []string{}, "set of labels to add")
+	f.StringSliceVar(&c.removeLabels, "remove-label", []string{}, "set of labels to remove")
+	return f
+}
+
+func (c *RelabelCommand) AutocompleteFlags() complete.Flags {
+	return command.MergeAutocompleteFlags(
+		c.Meta.AutocompleteFlags(command.FlagSetClient),
+		complete.Flags{
+			"--label":        complete.PredictAnything,
+			"--remove-label": complete.PredictAnything,
+		},
+	)
+}
+
+func (c *RelabelCommand) Run(args []string) int {
+	flags := c.FlagSet()
+	flags.Usage = func() { c.Ui.Output(c.Help()) }
+	if err := flags.Parse(args); err != nil {
+		c.Ui.Error(err.Error())
+		c.Ui.Error(command.CommandErrorText(c))
+		return 1
+	}
+
+	arguments, err := c.ParsedArguments(flags.Args())
+	if err != nil {
+		c.Ui.Error(err.Error())
+		c.Ui.Error(command.CommandErrorText(c))
+		return 1
+	}
+
+	imageName := arguments["image-name"].StringValue()
+
+	if len(c.addLabels) == 0 && len(c.removeLabels) == 0 {
+		c.Ui.Error("No labels specified\n")
+		return 1
+	}
+
+	dockerClient, err := dockercli.NewClientWithOpts(dockercli.FromEnv, dockercli.WithVersion(APIVERSION))
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf("Failed to create docker client: %s", err.Error()))
+		return 1
+	}
+
+	if _, _, err = dockerClient.ImageInspectWithRaw(context.Background(), imageName); err != nil {
+		if client.IsErrNotFound(err) {
+			c.Ui.Error(fmt.Sprintf("Failed to fetch image id: %s", err.Error()))
+			return 1
+		}
+	}
+
+	img, err := local.NewImage(imageName, dockerClient, local.FromBaseImage(imageName))
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf("Failed to create docker client: %s", err.Error()))
+		return 1
+	}
+
+	originalImageID, err := img.Identifier()
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf("Failed to fetch image id: %s", err.Error()))
+		return 1
+	}
+
+	inspect, _, err := dockerClient.ImageInspectWithRaw(context.Background(), originalImageID.String())
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf("Failed to inspect the source image: %s", err.Error()))
+		return 1
+	}
+
+	repoTags := inspect.RepoTags
+
+	appendLabels, err := parseNewLabels(c.addLabels)
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf("Failed to parse new labels: %s", err.Error()))
+		return 1
+	}
+
+	alternateTagsLabel := "com.dokku.docker-image-labeler/alternate-tags"
+	alternateTagValue, err := fetchTags(inspect, alternateTagsLabel)
+	if len(alternateTagValue) > 0 {
+		appendLabels[alternateTagsLabel] = alternateTagValue
+	}
+
+	removed, err := removeImageLabels(img, c.removeLabels)
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf("Failed removing labels: %s", err.Error()))
+		return 1
+	}
+
+	added, err := addImageLabels(img, appendLabels)
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf("Failed removing labels: %s", err.Error()))
+		return 1
+	}
+
+	if !removed && !added {
+		return 0
+	}
+
+	if err := img.Save(); err != nil {
+		c.Ui.Error(fmt.Sprintf("Failed to save image: %s", err.Error()))
+		return 1
+	}
+
+	newImageID, err := img.Identifier()
+	if err != nil {
+		c.Ui.Error(fmt.Sprintf("Failed to fetch image id: %s", err.Error()))
+		return 1
+	}
+
+	if newImageID == originalImageID {
+		c.Ui.Error(fmt.Sprintf("New and old image have the same identifier: %s", newImageID))
+		return 1
+	}
+
+	if len(repoTags) > 1 {
+		return 0
+	}
+
+	if len(repoTags) == 1 && repoTags[0] != imageName {
+		return 0
+	}
+
+	options := types.ImageRemoveOptions{
+		Force:         false,
+		PruneChildren: false,
+	}
+
+	if _, err := dockerClient.ImageRemove(context.Background(), originalImageID.String(), options); err != nil {
+		if _, ok := err.(errdefs.ErrConflict); ok {
+			c.Ui.Error(fmt.Sprintf("Warning: Failed to delete old image: %s", err.Error()))
+			return 0
+		}
+		c.Ui.Error(fmt.Sprintf("Failed to delete old image: %s", err.Error()))
+		return 1
+	}
+
+	return 0
+}
+
+func removeImageLabels(img *local.Image, labels []string) (bool, error) {
+	modified := false
+	for _, label := range labels {
+		existingValue, err := img.Label(label)
+		if err != nil {
+			return modified, fmt.Errorf("Error fetching label %s (%s)\n", label, err.Error())
+		}
+
+		if existingValue == "" {
+			continue
+		}
+
+		modified = true
+		if err := img.RemoveLabel(label); err != nil {
+			return modified, fmt.Errorf("Error removing label %s (%s)\n", label, err.Error())
+		}
+	}
+
+	return modified, nil
+}
+
+func addImageLabels(img *local.Image, labels map[string]string) (bool, error) {
+	modified := false
+	for key, value := range labels {
+		existingValue, err := img.Label(key)
+		if err != nil {
+			return modified, fmt.Errorf("Error fetching label %s (%s)\n", key, err.Error())
+		}
+
+		if existingValue == value {
+			continue
+		}
+
+		modified = true
+		if err := img.SetLabel(key, value); err != nil {
+			return modified, fmt.Errorf("Error setting label %s=%s (%s)\n", key, value, err.Error())
+		}
+	}
+
+	return modified, nil
+}
+
+func parseNewLabels(labels []string) (map[string]string, error) {
+	m := map[string]string{}
+	for _, label := range labels {
+		parts := strings.SplitN(label, "=", 2)
+		key := parts[0]
+		value := ""
+		if len(parts) == 2 {
+			value = parts[1]
+		}
+
+		if len(key) == 0 {
+			return m, errors.New("Invalid label specified")
+		}
+
+		m[key] = value
+	}
+
+	return m, nil
+}
+
+func fetchTags(inspect types.ImageInspect, label string) (string, error) {
+	if len(inspect.RepoTags) == 0 {
+		return "", nil
+	}
+
+	tags := inspect.RepoTags
+	s, ok := inspect.Config.Labels[label]
+	if ok {
+		var existingTags []string
+		if err := json.Unmarshal([]byte(s), &existingTags); err != nil {
+			return "", err
+		}
+
+		tags = append(tags, existingTags...)
+	}
+
+	tags = unique(tags)
+	originalRepoTags, err := json.Marshal(tags)
+	if err != nil {
+		return "", fmt.Errorf("Failed to encode image's original tags as JSON (%s)\n", err.Error())
+	}
+	return string(originalRepoTags), nil
+}
+
+func unique(intSlice []string) []string {
+	keys := make(map[string]bool)
+	list := []string{}
+	for _, entry := range intSlice {
+		if _, value := keys[entry]; !value {
+			keys[entry] = true
+			list = append(list, entry)
+		}
+	}
+	return list
+}

go.mod

@@ -5,23 +5,47 @@ go 1.19
 require (
 	github.com/buildpacks/imgutil v0.0.0-20220805205524-56137f75e24d
 	github.com/docker/docker v20.10.17+incompatible
+	github.com/josegonzalez/cli-skeleton v0.6.0
+	github.com/mitchellh/cli v1.1.4
+	github.com/posener/complete v1.2.3
 	github.com/spf13/pflag v1.0.5
 )
 
 require (
 	github.com/Azure/go-ansiterm v0.0.0-20210617225240-d185dfc1b5a1 // indirect
+	github.com/Masterminds/goutils v1.1.0 // indirect
+	github.com/Masterminds/semver/v3 v3.1.1 // indirect
+	github.com/Masterminds/sprig/v3 v3.2.0 // indirect
 	github.com/Microsoft/go-winio v0.5.2 // indirect
+	github.com/armon/go-radix v1.0.0 // indirect
+	github.com/bgentry/speakeasy v0.1.0 // indirect
 	github.com/docker/distribution v2.8.1+incompatible // indirect
 	github.com/docker/go-connections v0.4.0 // indirect
 	github.com/docker/go-units v0.4.0 // indirect
+	github.com/fatih/color v1.13.0 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/google/go-containerregistry v0.11.0 // indirect
+	github.com/google/uuid v1.3.0 // indirect
+	github.com/hashicorp/errwrap v1.0.0 // indirect
+	github.com/hashicorp/go-multierror v1.1.1 // indirect
+	github.com/huandu/xstrings v1.3.2 // indirect
+	github.com/imdario/mergo v0.3.11 // indirect
+	github.com/mattn/go-colorable v0.1.12 // indirect
+	github.com/mattn/go-isatty v0.0.14 // indirect
+	github.com/mitchellh/colorstring v0.0.0-20190213212951-d06e56a500db // indirect
+	github.com/mitchellh/copystructure v1.0.0 // indirect
+	github.com/mitchellh/reflectwalk v1.0.1 // indirect
 	github.com/moby/term v0.0.0-20220808134915-39b0c02b01ae // indirect
 	github.com/morikuni/aec v1.0.0 // indirect
 	github.com/opencontainers/go-digest v1.0.0 // indirect
 	github.com/opencontainers/image-spec v1.0.3-0.20220114050600-8b9d41f48198 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
+	github.com/rs/zerolog v1.27.0 // indirect
+	github.com/shopspring/decimal v1.2.0 // indirect
 	github.com/sirupsen/logrus v1.9.0 // indirect
+	github.com/spf13/cast v1.4.1 // indirect
+	golang.org/x/crypto v0.0.0-20210921155107-089bfa567519 // indirect
 	golang.org/x/net v0.0.0-20220805013720-a33c5aa5df48 // indirect
 	golang.org/x/sys v0.0.0-20220808155132-1c4a2a72c664 // indirect
+	golang.org/x/term v0.0.0-20210927222741-03fcf44c2211 // indirect
 )