add a new run command along with a new flag

cmd/executor/cmd/root.go

@@ -174,6 +174,7 @@ func addKanikoOptionsFlags() {
 	RootCmd.PersistentFlags().BoolVarP(&opts.IgnoreVarRun, "whitelist-var-run", "", true, "Ignore /var/run directory when taking image snapshot. Set it to false to preserve /var/run/ in destination image. (Default true).")
 	RootCmd.PersistentFlags().VarP(&opts.Labels, "label", "", "Set metadata for an image. Set it repeatedly for multiple labels.")
 	RootCmd.PersistentFlags().BoolVarP(&opts.SkipUnusedStages, "skip-unused-stages", "", false, "Build only used stages if defined to true. Otherwise it builds by default all stages, even the unnecessaries ones until it reaches the target stage / end of Dockerfile")
+	RootCmd.PersistentFlags().BoolVarP(&opts.RunV2, "use-new-run", "", false, "Experimental run command to detect file system changes. This new run command does no rely on snapshotting to detect changes.")
 }
 
 // addHiddenFlags marks certain flags as hidden from the executor help text

integration/dockerfiles/Dockerfile_test_run_new

@@ -0,0 +1,26 @@
+# Copyright 2018 Google, Inc. All rights reserved.
+#
+# 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.
+
+FROM debian:9.11
+RUN echo "hey" > /etc/foo
+RUN echo "baz" > /etc/baz
+RUN cp /etc/baz /etc/bar
+RUN rm /etc/baz
+
+# Test with ARG
+ARG file
+RUN echo "run" > $file
+
+RUN echo "test home" > $HOME/file
+COPY context/foo $HOME/foo

integration/images.go

@@ -48,6 +48,7 @@ const (
 // Arguments to build Dockerfiles with, used for both docker and kaniko builds
 var argsMap = map[string][]string{
 	"Dockerfile_test_run":        {"file=/file"},
+	"Dockerfile_test_run_new":    {"file=/file"},
 	"Dockerfile_test_workdir":    {"workdir=/arg/workdir"},
 	"Dockerfile_test_add":        {"file=context/foo"},
 	"Dockerfile_test_arg_secret": {"SSH_PRIVATE_KEY", "SSH_PUBLIC_KEY=Pµbl1cK€Y"},
@@ -74,6 +75,7 @@ var additionalDockerFlagsMap = map[string][]string{
 // Arguments to build Dockerfiles with when building with kaniko
 var additionalKanikoFlagsMap = map[string][]string{
 	"Dockerfile_test_add":        {"--single-snapshot"},
+	"Dockerfile_test_run_new":    {"--use-new-run=true"},
 	"Dockerfile_test_scratch":    {"--single-snapshot"},
 	"Dockerfile_test_maintainer": {"--single-snapshot"},
 	"Dockerfile_test_target":     {"--target=second"},

pkg/commands/base_command.go

@@ -51,3 +51,7 @@ func (b *BaseCommand) RequiresUnpackedFS() bool {
 func (b *BaseCommand) ShouldCacheOutput() bool {
 	return false
 }
+
+func (a *BaseCommand) ShouldDetectDeletedFiles() bool {
+	return false
+}

pkg/commands/commands.go

@@ -52,11 +52,17 @@ type DockerCommand interface {
 	RequiresUnpackedFS() bool
 
 	ShouldCacheOutput() bool
+
+	// ShouldDetectDeletedFiles turns true if the command could delete files.
+	ShouldDetectDeletedFiles() bool
 }
 
-func GetCommand(cmd instructions.Command, buildcontext string) (DockerCommand, error) {
+func GetCommand(cmd instructions.Command, buildcontext string, useNewRun bool) (DockerCommand, error) {
 	switch c := cmd.(type) {
 	case *instructions.RunCommand:
+		if useNewRun {
+			return &RunMarkerCommand{cmd: c}, nil
+		}
 		return &RunCommand{cmd: c}, nil
 	case *instructions.CopyCommand:
 		return &CopyCommand{cmd: c, buildcontext: buildcontext}, nil

pkg/commands/run.go

@@ -46,8 +46,12 @@ var (
 )
 
 func (r *RunCommand) ExecuteCommand(config *v1.Config, buildArgs *dockerfile.BuildArgs) error {
+	return runCommandInExec(config, buildArgs, r.cmd)
+}
+
+func runCommandInExec(config *v1.Config, buildArgs *dockerfile.BuildArgs, cmdRun *instructions.RunCommand) error {
 	var newCommand []string
-	if r.cmd.PrependShell {
+	if cmdRun.PrependShell {
 		// This is the default shell on Linux
 		var shell []string
 		if len(config.Shell) > 0 {
@@ -56,9 +60,9 @@ func (r *RunCommand) ExecuteCommand(config *v1.Config, buildArgs *dockerfile.Bui
 			shell = append(shell, "/bin/sh", "-c")
 		}
 
-		newCommand = append(shell, strings.Join(r.cmd.CmdLine, " "))
+		newCommand = append(shell, strings.Join(cmdRun.CmdLine, " "))
 	} else {
-		newCommand = r.cmd.CmdLine
+		newCommand = cmdRun.CmdLine
 	}
 
 	logrus.Infof("cmd: %s", newCommand[0])
@@ -111,7 +115,6 @@ func (r *RunCommand) ExecuteCommand(config *v1.Config, buildArgs *dockerfile.Bui
 	if err := syscall.Kill(-pgid, syscall.SIGKILL); err != nil && err.Error() != "no such process" {
 		return err
 	}
-
 	return nil
 }
 

pkg/commands/run_marker.go

@@ -0,0 +1,106 @@
+/*
+Copyright 2018 Google LLC
+
+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 commands
+
+import (
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+
+	"github.com/GoogleContainerTools/kaniko/pkg/dockerfile"
+	"github.com/GoogleContainerTools/kaniko/pkg/util"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/moby/buildkit/frontend/dockerfile/instructions"
+)
+
+type RunMarkerCommand struct {
+	BaseCommand
+	cmd   *instructions.RunCommand
+	Files []string
+}
+
+func (r *RunMarkerCommand) ExecuteCommand(config *v1.Config, buildArgs *dockerfile.BuildArgs) error {
+	// run command `touch filemarker`
+	markerFile, err := ioutil.TempFile("", "marker")
+	defer func() {
+		os.Remove(markerFile.Name())
+	}()
+
+	if err := runCommandInExec(config, buildArgs, r.cmd); err != nil {
+		return err
+	}
+
+	// run command find to find all new files generated
+	find := exec.Command("find", "/", "-newer", markerFile.Name())
+	out, err := find.Output()
+	if err != nil {
+		r.Files = []string{}
+		return nil
+	}
+
+	r.Files = []string{}
+	s := strings.Split(string(out), "\n")
+	for _, path := range s {
+		path = filepath.Clean(path)
+		if util.IsDestDir(path) || util.CheckIgnoreList(path) {
+			continue
+		}
+		r.Files = append(r.Files, path)
+	}
+	return nil
+}
+
+// String returns some information about the command for the image config
+func (r *RunMarkerCommand) String() string {
+	return r.cmd.String()
+}
+
+func (r *RunMarkerCommand) FilesToSnapshot() []string {
+	return nil
+}
+
+func (r *RunMarkerCommand) ProvidesFilesToSnapshot() bool {
+	return false
+}
+
+// CacheCommand returns true since this command should be cached
+func (r *RunMarkerCommand) CacheCommand(img v1.Image) DockerCommand {
+
+	return &CachingRunCommand{
+		img:       img,
+		cmd:       r.cmd,
+		extractFn: util.ExtractFile,
+	}
+}
+
+func (r *RunMarkerCommand) MetadataOnly() bool {
+	return false
+}
+
+func (r *RunMarkerCommand) RequiresUnpackedFS() bool {
+	return true
+}
+
+func (r *RunMarkerCommand) ShouldCacheOutput() bool {
+	return true
+}
+
+func (b *BaseCommand) ShouldDetectDelete() bool {
+	return true
+}

pkg/config/options.go

@@ -57,6 +57,7 @@ type KanikoOptions struct {
 	Cleanup                 bool
 	IgnoreVarRun            bool
 	SkipUnusedStages        bool
+	RunV2                   bool
 }
 
 // WarmerOptions are options that are set by command line arguments to the cache warmer.

pkg/executor/build.go

@@ -62,7 +62,7 @@ type cachePusher func(*config.KanikoOptions, string, string, string) error
 type snapShotter interface {
 	Init() error
 	TakeSnapshotFS() (string, error)
-	TakeSnapshot([]string) (string, error)
+	TakeSnapshot([]string, bool) (string, error)
 }
 
 // stageBuilder contains all fields necessary to build one stage of a Dockerfile
@@ -127,7 +127,7 @@ func newStageBuilder(opts *config.KanikoOptions, stage config.KanikoStage, cross
 	}
 
 	for _, cmd := range s.stage.Commands {
-		command, err := commands.GetCommand(cmd, opts.SrcContext)
+		command, err := commands.GetCommand(cmd, opts.SrcContext, opts.RunV2)
 		if err != nil {
 			return nil, err
 		}
@@ -382,7 +382,7 @@ func (s *stageBuilder) build() error {
 				return errors.Wrap(err, "failed to save layer")
 			}
 		} else {
-			tarPath, err := s.takeSnapshot(files)
+			tarPath, err := s.takeSnapshot(files, command.ShouldDetectDeletedFiles())
 			if err != nil {
 				return errors.Wrap(err, "failed to take snapshot")
 			}
@@ -416,7 +416,7 @@ func (s *stageBuilder) build() error {
 	return nil
 }
 
-func (s *stageBuilder) takeSnapshot(files []string) (string, error) {
+func (s *stageBuilder) takeSnapshot(files []string, shdDelete bool) (string, error) {
 	var snapshot string
 	var err error
 
@@ -426,7 +426,7 @@ func (s *stageBuilder) takeSnapshot(files []string) (string, error) {
 	} else {
 		// Volumes are very weird. They get snapshotted in the next command.
 		files = append(files, util.Volumes()...)
-		snapshot, err = s.snapshotter.TakeSnapshot(files)
+		snapshot, err = s.snapshotter.TakeSnapshot(files, shdDelete)
 	}
 	timing.DefaultRun.Stop(t)
 	return snapshot, err

pkg/executor/build_test.go

@@ -1246,6 +1246,7 @@ func getCommands(dir string, cmds []instructions.Command) []commands.DockerComma
 		cmd, err := commands.GetCommand(
 			c,
 			dir,
+			false,
 		)
 		if err != nil {
 			panic(err)

pkg/executor/fakes.go

@@ -73,6 +73,9 @@ func (m MockDockerCommand) RequiresUnpackedFS() bool {
 func (m MockDockerCommand) ShouldCacheOutput() bool {
 	return true
 }
+func (m MockDockerCommand) ShouldDetectDeletedFiles() bool {
+	return false
+}
 
 type MockCachedDockerCommand struct {
 	contextFiles []string
@@ -93,6 +96,9 @@ func (m MockCachedDockerCommand) ProvidesFilesToSnapshot() bool {
 func (m MockCachedDockerCommand) CacheCommand(image v1.Image) commands.DockerCommand {
 	return nil
 }
+func (m MockCachedDockerCommand) ShouldDetectDeletedFiles() bool {
+	return false
+}
 func (m MockCachedDockerCommand) FilesUsedFromContext(c *v1.Config, args *dockerfile.BuildArgs) ([]string, error) {
 	return m.contextFiles, nil
 }

pkg/snapshot/snapshot.go

@@ -62,7 +62,7 @@ func (s *Snapshotter) Key() (string, error) {
 
 // TakeSnapshot takes a snapshot of the specified files, avoiding directories in the ignorelist, and creates
 // a tarball of the changed files. Return contents of the tarball, and whether or not any files were changed
-func (s *Snapshotter) TakeSnapshot(files []string) (string, error) {
+func (s *Snapshotter) TakeSnapshot(files []string, shdCheckDelete bool) (string, error) {
 	f, err := ioutil.TempFile(config.KanikoDir, "")
 	if err != nil {
 		return "", err
@@ -92,9 +92,30 @@ func (s *Snapshotter) TakeSnapshot(files []string) (string, error) {
 		}
 	}
 
+	// Get whiteout paths
+	filesToWhiteout := []string{}
+	if shdCheckDelete {
+		existingPaths := s.l.getFlattenedPathsForWhiteOut()
+		foundFiles := walkFS(s.directory)
+		for _, file := range foundFiles {
+			delete(existingPaths, file)
+		}
+		// The paths left here are the ones that have been deleted in this layer.
+		filesToWhiteOut := []string{}
+		for path := range existingPaths {
+			// Only add the whiteout if the directory for the file still exists.
+			dir := filepath.Dir(path)
+			if _, ok := existingPaths[dir]; !ok {
+				if s.l.MaybeAddWhiteout(path) {
+					logrus.Debugf("Adding whiteout for %s", path)
+					filesToWhiteOut = append(filesToWhiteOut, path)
+				}
+			}
+		}
+	}
 	t := util.NewTar(f)
 	defer t.Close()
-	if err := writeToTar(t, filesToAdd, nil); err != nil {
+	if err := writeToTar(t, filesToAdd, filesToWhiteout); err != nil {
 		return "", err
 	}
 	return f.Name(), nil
@@ -133,31 +154,8 @@ func (s *Snapshotter) scanFullFilesystem() ([]string, []string, error) {
 
 	s.l.Snapshot()
 
-	timer := timing.Start("Walking filesystem")
-
-	foundPaths := make([]string, 0)
-
-	godirwalk.Walk(s.directory, &godirwalk.Options{
-		Callback: func(path string, ent *godirwalk.Dirent) error {
-			if util.IsInIgnoreList(path) {
-				if util.IsDestDir(path) {
-					logrus.Tracef("Skipping paths under %s, as it is a ignored directory", path)
-
-					return filepath.SkipDir
-				}
-
-				return nil
-			}
-
-			foundPaths = append(foundPaths, path)
-
-			return nil
-		},
-		Unsorted: true,
-	},
-	)
-	timing.DefaultRun.Stop(timer)
-	timer = timing.Start("Resolving Paths")
+	foundPaths := walkFS(s.directory)
+	timer := timing.Start("Resolving Paths")
 	// First handle whiteouts
 	//   Get a list of all the files that existed before this layer
 	existingPaths := s.l.getFlattenedPathsForWhiteOut()
@@ -267,3 +265,29 @@ func filesWithLinks(path string) ([]string, error) {
 	}
 	return []string{path, link}, nil
 }
+
+func walkFS(dir string) []string {
+	foundPaths := make([]string, 0)
+	timer := timing.Start("Walking filesystem")
+	godirwalk.Walk(dir, &godirwalk.Options{
+		Callback: func(path string, ent *godirwalk.Dirent) error {
+			if util.IsInIgnoreList(path) {
+				if util.IsDestDir(path) {
+					logrus.Tracef("Skipping paths under %s, as it is a ignored directory", path)
+
+					return filepath.SkipDir
+				}
+
+				return nil
+			}
+
+			foundPaths = append(foundPaths, path)
+
+			return nil
+		},
+		Unsorted: true,
+	},
+	)
+	timing.DefaultRun.Stop(timer)
+	return foundPaths
+}

pkg/snapshot/snapshot_test.go

@@ -212,7 +212,7 @@ func TestSnapshotFiles(t *testing.T) {
 	filesToSnapshot := []string{
 		filepath.Join(testDir, "foo"),
 	}
-	tarPath, err := snapshotter.TakeSnapshot(filesToSnapshot)
+	tarPath, err := snapshotter.TakeSnapshot(filesToSnapshot, false)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -359,7 +359,7 @@ func TestSnasphotPreservesFileOrder(t *testing.T) {
 		}
 
 		// Take a snapshot
-		tarPath, err := snapshotter.TakeSnapshot(filesToSnapshot)
+		tarPath, err := snapshotter.TakeSnapshot(filesToSnapshot, false)
 
 		if err != nil {
 			t.Fatalf("Error taking snapshot of fs: %s", err)