adding VOLUME command (#62)

* adding VOLUME command

* proper test project

* general fixes

* fixing project name

* fixing volume unit test

* fixing integration test

* adding tests

* adding util test

* fixing test

* actually create the volume mounted directory

* fix test

executor/cmd/root.go

@@ -146,6 +146,7 @@ func execute() error {
 			if err != nil {
 				return err
 			}
+			util.MoveVolumeWhitelistToWhitelist()
 			if contents == nil {
 				logrus.Info("No files were changed, appending empty layer to config.")
 				sourceImage.AppendConfigHistory(constants.Author, true)

integration_tests/dockerfiles/Dockerfile_test_volume

@@ -0,0 +1,7 @@
+FROM gcr.io/google-appengine/debian9
+RUN mkdir /foo
+RUN echo "hello" > /foo/hey
+VOLUME /foo/bar /tmp
+ENV VOL /baz/bat
+VOLUME ["${VOL}"]
+RUN echo "hello again" > /tmp/hey

integration_tests/dockerfiles/config_test_volume.json

@@ -0,0 +1,12 @@
+[
+  {
+    "Image1": "gcr.io/kbuild-test/docker-test-volume:latest",
+    "Image2": "gcr.io/kbuild-test/kbuild-test-volume:latest",
+    "DiffType": "File",
+    "Diff": {
+      "Adds": null,
+      "Dels": null,
+      "Mods": null
+    }
+  }
+]

integration_tests/integration_test_yaml.go

@@ -94,6 +94,14 @@ var fileTests = []struct {
 		kbuildContext:  buildcontextPath,
 		repo:           "test-workdir",
 	},
+	{
+		description:    "test volume",
+		dockerfilePath: "/workspace/integration_tests/dockerfiles/Dockerfile_test_volume",
+		configPath:     "/workspace/integration_tests/dockerfiles/config_test_volume.json",
+		dockerContext:  buildcontextPath,
+		kbuildContext:  buildcontextPath,
+		repo:           "test-volume",
+	},
 	{
 		description:    "test add",
 		dockerfilePath: "/workspace/integration_tests/dockerfiles/Dockerfile_test_add",

pkg/commands/commands.go

@@ -56,6 +56,8 @@ func GetCommand(cmd instructions.Command, buildcontext string) (DockerCommand, e
 		return &LabelCommand{cmd: c}, nil
 	case *instructions.UserCommand:
 		return &UserCommand{cmd: c}, nil
+	case *instructions.VolumeCommand:
+		return &VolumeCommand{cmd: c}, nil
 	}
 	return nil, errors.Errorf("%s is not a supported command", cmd.Name())
 }

pkg/commands/volume.go

@@ -0,0 +1,71 @@
+/*
+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 (
+	"github.com/GoogleCloudPlatform/k8s-container-builder/pkg/util"
+	"github.com/containers/image/manifest"
+	"github.com/docker/docker/builder/dockerfile/instructions"
+	"github.com/sirupsen/logrus"
+	"os"
+	"strings"
+)
+
+type VolumeCommand struct {
+	cmd           *instructions.VolumeCommand
+	snapshotFiles []string
+}
+
+func (v *VolumeCommand) ExecuteCommand(config *manifest.Schema2Config) error {
+	logrus.Info("cmd: VOLUME")
+	volumes := v.cmd.Volumes
+	resolvedVolumes, err := util.ResolveEnvironmentReplacementList(volumes, config.Env, true)
+	if err != nil {
+		return err
+	}
+	existingVolumes := config.Volumes
+	if existingVolumes == nil {
+		existingVolumes = map[string]struct{}{}
+	}
+	for _, volume := range resolvedVolumes {
+		var x struct{}
+		existingVolumes[volume] = x
+		err := util.AddPathToVolumeWhitelist(volume)
+		if err != nil {
+			return err
+		}
+
+		logrus.Infof("Creating directory %s", volume)
+		if err := os.MkdirAll(volume, 0755); err != nil {
+			return err
+		}
+
+		//Check if directory already exists?
+		v.snapshotFiles = append(v.snapshotFiles, volume)
+	}
+	config.Volumes = existingVolumes
+
+	return nil
+}
+
+func (v *VolumeCommand) FilesToSnapshot() []string {
+	return v.snapshotFiles
+}
+
+func (v *VolumeCommand) CreatedBy() string {
+	return strings.Join(append([]string{v.cmd.Name()}, v.cmd.Volumes...), " ")
+}

pkg/commands/volume_test.go

@@ -0,0 +1,54 @@
+/*
+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 (
+	"github.com/GoogleCloudPlatform/k8s-container-builder/testutil"
+	"github.com/containers/image/manifest"
+	"github.com/docker/docker/builder/dockerfile/instructions"
+	"testing"
+)
+
+func TestUpdateVolume(t *testing.T) {
+	cfg := &manifest.Schema2Config{
+		Env: []string{
+			"VOLUME=/etc",
+		},
+		Volumes: map[string]struct{}{},
+	}
+
+	volumes := []string{
+		"/tmp",
+		"/var/lib",
+		"$VOLUME",
+	}
+
+	volumeCmd := &VolumeCommand{
+		cmd: &instructions.VolumeCommand{
+			Volumes: volumes,
+		},
+		snapshotFiles: []string{},
+	}
+
+	expectedVolumes := map[string]struct{}{
+		"/tmp":     {},
+		"/var/lib": {},
+		"/etc":     {},
+	}
+
+	err := volumeCmd.ExecuteCommand(cfg)
+	testutil.CheckErrorAndDeepEqual(t, false, err, expectedVolumes, cfg.Volumes)
+}

pkg/util/fs_util.go

@@ -31,6 +31,7 @@ import (
 )
 
 var whitelist = []string{"/kbuild"}
+var volumeWhitelist = []string{}
 
 // ExtractFileSystemFromImage pulls an image and unpacks it to a file system at root
 func ExtractFileSystemFromImage(img string) error {
@@ -156,6 +157,25 @@ func CreateFile(path string, reader io.Reader, perm os.FileMode) error {
 	return dest.Chmod(perm)
 }
 
+// AddPathToVolumeWhitelist adds the given path to the volume whitelist
+// It will get snapshotted when the VOLUME command is run then ignored
+// for subsequent commands.
+func AddPathToVolumeWhitelist(path string) error {
+	logrus.Infof("adding %s to volume whitelist", path)
+	volumeWhitelist = append(volumeWhitelist, path)
+	return nil
+}
+
+// MoveVolumeWhitelistToWhitelist copies over all directories that were volume mounted
+// in this step to be whitelisted for all subsequent docker commands.
+func MoveVolumeWhitelistToWhitelist() error {
+	if len(volumeWhitelist) > 0 {
+		whitelist = append(whitelist, volumeWhitelist...)
+		volumeWhitelist = []string{}
+	}
+	return nil
+}
+
 // DownloadFileToDest downloads the file at rawurl to the given dest for the ADD command
 // From add command docs:
 // 	1. If <src> is a remote file URL: