Add image squash command

Signed-off-by: weipeng <weip3@chinatelecom.cn>

cmd/nerdctl/image/image.go

@@ -42,6 +42,7 @@ func NewImageCommand() *cobra.Command {
 		NewLoadCommand(),
 		NewSaveCommand(),
 		NewTagCommand(),
+		NewSquashCommand(),
 		imageRmCommand(),
 		newImageConvertCommand(),
 		newImageInspectCommand(),

cmd/nerdctl/image/image_squash.go

@@ -0,0 +1,102 @@
+/*
+   Copyright The containerd 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 image
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+
+	"github.com/containerd/nerdctl/v2/cmd/nerdctl/helpers"
+	"github.com/containerd/nerdctl/v2/pkg/api/types"
+	"github.com/containerd/nerdctl/v2/pkg/clientutil"
+	"github.com/containerd/nerdctl/v2/pkg/cmd/image"
+)
+
+func addSquashFlags(cmd *cobra.Command) {
+	cmd.Flags().IntP("layer-count", "c", 0, "The number of layers that can be compressed")
+	cmd.Flags().StringP("layer-digest", "d", "", "The digest of the layer to be compressed")
+	cmd.Flags().StringP("author", "a", "", `Author (e.g., "nerdctl contributor <nerdctl-dev@example.com>")`)
+	cmd.Flags().StringP("message", "m", "", "Commit message")
+}
+
+func NewSquashCommand() *cobra.Command {
+	var squashCommand = &cobra.Command{
+		Use:           "squash [flags] SOURCE_IMAGE TAG_IMAGE",
+		Short:         "Compress the number of layers of the image",
+		Args:          helpers.IsExactArgs(2),
+		RunE:          squashAction,
+		SilenceUsage:  true,
+		SilenceErrors: true,
+	}
+	addSquashFlags(squashCommand)
+	return squashCommand
+}
+
+func processSquashCommandFlags(cmd *cobra.Command, args []string) (options types.ImageSquashOptions, err error) {
+	globalOptions, err := helpers.ProcessRootCmdFlags(cmd)
+	if err != nil {
+		return options, err
+	}
+	layerCount, err := cmd.Flags().GetInt("layer-count")
+	if err != nil {
+		return options, err
+	}
+	layerDigest, err := cmd.Flags().GetString("layer-digest")
+	if err != nil {
+		return options, err
+	}
+	author, err := cmd.Flags().GetString("author")
+	if err != nil {
+		return options, err
+	}
+	message, err := cmd.Flags().GetString("message")
+	if err != nil {
+		return options, err
+	}
+
+	options = types.ImageSquashOptions{
+		GOptions: globalOptions,
+
+		Author:  author,
+		Message: message,
+
+		SourceImageRef:  args[0],
+		TargetImageName: args[1],
+
+		SquashLayerCount:  layerCount,
+		SquashLayerDigest: layerDigest,
+	}
+	return options, nil
+}
+
+func squashAction(cmd *cobra.Command, args []string) error {
+	options, err := processSquashCommandFlags(cmd, args)
+	if err != nil {
+		return err
+	}
+	if !options.GOptions.Experimental {
+		return fmt.Errorf("squash is an experimental feature, please enable experimental mode")
+	}
+	client, ctx, cancel, err := clientutil.NewClient(cmd.Context(), options.GOptions.Namespace, options.GOptions.Address)
+	if err != nil {
+		return err
+	}
+	defer cancel()
+
+	return image.Squash(ctx, client, options)
+}

cmd/nerdctl/main.go

@@ -295,6 +295,7 @@ Config file ($NERDCTL_TOML): %s
 		image.NewTagCommand(),
 		image.NewRmiCommand(),
 		image.NewHistoryCommand(),
+		image.NewSquashCommand(),
 		// #endregion
 
 		// #region System

pkg/api/types/image_types.go

@@ -287,3 +287,23 @@ type SociOptions struct {
 	// Minimum layer size to build zTOC for. Smaller layers won't have zTOC and not lazy pulled. Default is 10 MiB.
 	MinLayerSize int64
 }
+
+// ImageSquashOptions specifies options for `nerdctl image squash`.
+type ImageSquashOptions struct {
+	// GOptions is the global options
+	GOptions GlobalCommandOptions
+
+	// Author (e.g., "nerdctl contributor <nerdctl-dev@example.com>")
+	Author string
+	// Commit message
+	Message string
+	// SourceImageRef is the image to be squashed
+	SourceImageRef string
+	// TargetImageName is the name of the squashed image
+	TargetImageName string
+
+	// SquashLayerCount is the number of layers to squash
+	SquashLayerCount int
+	// SquashLayerDigest is the digest of the layer to squash
+	SquashLayerDigest string
+}