Add image squash ut & Update docs/command-reference.md

Signed-off-by: weipeng <[email protected]>

cmd/nerdctl/image/image_squash.go

@@ -28,15 +28,15 @@ import (
 )
 
 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 <[email protected]>")`)
-	cmd.Flags().StringP("message", "m", "", "Commit message")
+	cmd.Flags().IntP("last-n-layer", "n", 0, "The number of specify squashing the last N (N=layer-count) layers")
+	cmd.Flags().StringP("author", "a", "nerdctl", `Author (e.g., "nerdctl contributor <[email protected]>")`)
+	cmd.Flags().StringP("message", "m", "generated by nerdctl squash", "Commit message")
 }
 
+// NewSquashCommand returns a new `squash` command to compress the number of layers of the image
 func NewSquashCommand() *cobra.Command {
 	var squashCommand = &cobra.Command{
-		Use:           "squash [flags] SOURCE_IMAGE TAG_IMAGE",
+		Use:           "squash [flags] SOURCE_IMAGE TARGET_IMAGE",
 		Short:         "Compress the number of layers of the image",
 		Args:          helpers.IsExactArgs(2),
 		RunE:          squashAction,
@@ -52,11 +52,7 @@ func processSquashCommandFlags(cmd *cobra.Command, args []string) (options types
 	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")
+	layerN, err := cmd.Flags().GetInt("last-n-layer")
 	if err != nil {
 		return options, err
 	}
@@ -78,8 +74,7 @@ func processSquashCommandFlags(cmd *cobra.Command, args []string) (options types
 		SourceImageRef:  args[0],
 		TargetImageName: args[1],
 
-		SquashLayerCount:  layerCount,
-		SquashLayerDigest: layerDigest,
+		SquashLayerLastN: layerN,
 	}
 	return options, nil
 }

cmd/nerdctl/image/image_squash_test.go

@@ -0,0 +1,100 @@
+/*
+   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"
+	"testing"
+
+	"gotest.tools/v3/assert"
+
+	"github.com/containerd/nerdctl/v2/pkg/testutil"
+	"github.com/containerd/nerdctl/v2/pkg/testutil/nerdtest"
+	"github.com/containerd/nerdctl/v2/pkg/testutil/test"
+)
+
+func squashIdentifierName(identifier string) string {
+	return fmt.Sprintf("%s-squash", identifier)
+}
+
+func secondCommitedIdentifierName(identifier string) string {
+	return fmt.Sprintf("%s-second", identifier)
+}
+
+func TestSquash(t *testing.T) {
+	testCase := nerdtest.Setup()
+
+	require := test.Require(
+		test.Not(nerdtest.Docker),
+		nerdtest.CGroup,
+	)
+
+	testCase.SubTests = []*test.Case{
+		{
+			Description: "by last-n-layer",
+			Require:     require,
+			NoParallel:  true,
+			Cleanup: func(data test.Data, helpers test.Helpers) {
+				identifier := data.Identifier()
+				secondIdentifier := secondCommitedIdentifierName(identifier)
+				squashIdentifier := squashIdentifierName(identifier)
+				helpers.Anyhow("rm", "-f", identifier)
+				helpers.Anyhow("rm", "-f", secondIdentifier)
+				helpers.Anyhow("rm", "-f", squashIdentifier)
+
+				helpers.Anyhow("rmi", "-f", secondIdentifier)
+				helpers.Anyhow("rmi", "-f", identifier)
+				helpers.Anyhow("rmi", "-f", squashIdentifier)
+				helpers.Anyhow("image", "prune", "-f")
+			},
+			Setup: func(data test.Data, helpers test.Helpers) {
+				identifier := data.Identifier()
+				helpers.Ensure("run", "-d", "--name", identifier, testutil.CommonImage, "sleep", nerdtest.Infinity)
+				helpers.Ensure("exec", identifier, "sh", "-euxc", `echo hello-first-commit > /foo`)
+				helpers.Ensure("commit", "-c", `CMD ["cat", "/foo"]`, "-m", `first commit`, "--pause=true", identifier, identifier)
+				out := helpers.Capture("run", "--rm", identifier)
+				assert.Equal(t, out, "hello-first-commit\n")
+
+				secondIdentifier := secondCommitedIdentifierName(identifier)
+				helpers.Ensure("run", "-d", "--name", secondIdentifier, identifier, "sleep", nerdtest.Infinity)
+				helpers.Ensure("exec", secondIdentifier, "sh", "-euxc", `echo hello-second-commit > /bar && echo hello-squash-commit > /foo`)
+				helpers.Ensure("commit", "-c", `CMD ["cat", "/foo", "/bar"]`, "-m", `second commit`, "--pause=true", secondIdentifier, secondIdentifier)
+				out = helpers.Capture("run", "--rm", secondIdentifier)
+				assert.Equal(t, out, "hello-squash-commit\nhello-second-commit\n")
+
+				squashIdentifier := squashIdentifierName(identifier)
+				helpers.Ensure("image", "squash", "-n", "2", "-m", "squash commit", secondIdentifier, squashIdentifier)
+				out = helpers.Capture("run", "--rm", squashIdentifier)
+				assert.Equal(t, out, "hello-squash-commit\nhello-second-commit\n")
+			},
+			Command: func(data test.Data, helpers test.Helpers) test.TestableCommand {
+				identifier := data.Identifier()
+
+				squashIdentifier := squashIdentifierName(identifier)
+				return helpers.Command("image", "history", "--human=true", "--format=json", squashIdentifier)
+			},
+			Expected: test.Expects(0, nil, func(stdout string, info string, t *testing.T) {
+				history, err := decode(stdout)
+				assert.NilError(t, err, info)
+				assert.Equal(t, len(history), 3, info)
+				assert.Equal(t, history[0].Comment, "squash commit", info)
+			}),
+		},
+	}
+
+	testCase.Run(t)
+}

cmd/nerdctl/main.go

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

docs/command-reference.md

@@ -994,6 +994,24 @@ Flags:
 - `--platform=<PLATFORM>`        : Convert content for a specific platform
 - `--all-platforms`              : Convert content for all platforms (default: false)
 
+### :nerd_face: nerdctl image squash
+
+Squash last-n-layer into a single layer.
+
+Usage: `nerdctl image squash [OPTIONS] SOURCE_IMAGE[:TAG] TARGET_IMAGE[:TAG]`
+
+Example:
+
+```bash
+nerdctl image pull example.com/foo:latest
+nerdctl image squash ----last-n-layer=2 --message="generated by nerdctl squash" example.com/foo:latest example.com/foo:squashed
+```
+
+Flags:
+- `-n --last-n-layer=<NUMBER>`: The number of specify squashing the last N (N=layer-count) layers
+- `-m --message=<MESSAGE>`: Commit message for the squashed image
+- `-a --author=<AUTHOR>`: Author of the squashed image
+
 ## Registry
 
 ### :whale: nerdctl login

pkg/api/types/image_types.go

@@ -305,8 +305,6 @@ type ImageSquashOptions struct {
 	// 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
+	// SquashLayerLastN is the number of layers to squash
+	SquashLayerLastN int
 }