Remove Docker dependency for retrieving image filesystem

cmd/analyze.go

@@ -56,20 +56,23 @@ func checkAnalyzeArgNum(args []string) error {
 	return nil
 }
 
-func analyzeImage(imageArg string, analyzerArgs []string) error {
+func analyzeImage(imageName string, analyzerArgs []string) error {
+	cli, err := NewClient()
+	if err != nil {
+		return fmt.Errorf("Error getting docker client for differ: %s", err)
+	}
+	defer cli.Close()
+
 	analyzeTypes, err := differs.GetAnalyzers(analyzerArgs)
 	if err != nil {
 		glog.Error(err.Error())
 		return errors.New("Could not perform image analysis")
 	}
 
-	cli, err := NewClient()
-	if err != nil {
-		return fmt.Errorf("Error getting docker client for differ: %s", err)
-	}
-	defer cli.Close()
+	prefixedName := processImageName(imageName)
+
 	ip := pkgutil.ImagePrepper{
-		Source: imageArg,
+		Source: prefixedName,
 		Client: cli,
 	}
 	image, err := ip.GetImage()

cmd/diff.go

@@ -35,10 +35,10 @@ var diffCmd = &cobra.Command{
 	Long:  `Compares two images using the specifed analyzers as indicated via flags (see documentation for available ones).`,
 	Args: func(cmd *cobra.Command, args []string) error {
 		if err := validateArgs(args, checkDiffArgNum); err != nil {
-			return errors.New(err.Error())
+			return err
 		}
 		if err := checkIfValidAnalyzer(types); err != nil {
-			return errors.New(err.Error())
+			return err
 		}
 		return nil
 	},
@@ -52,21 +52,20 @@ var diffCmd = &cobra.Command{
 
 func checkDiffArgNum(args []string) error {
 	if len(args) != 2 {
-		return errors.New("'diff' requires two images as arguments: container diff [image1] [image2]")
+		return errors.New("'diff' requires two images as arguments: container-diff diff [image1] [image2]")
 	}
 	return nil
 }
 
 func diffImages(image1Arg, image2Arg string, diffArgs []string) error {
 	diffTypes, err := differs.GetAnalyzers(diffArgs)
 	if err != nil {
-		glog.Error(err.Error())
-		return errors.New("Could not perform image diff")
+		return fmt.Errorf("err msg: %s", err.Error())
 	}
 
 	cli, err := NewClient()
 	if err != nil {
-		return fmt.Errorf("Error getting docker client for differ: %s", err)
+		return fmt.Errorf("err msg: %s", err)
 	}
 	defer cli.Close()
 	var wg sync.WaitGroup
@@ -81,8 +80,10 @@ func diffImages(image1Arg, image2Arg string, diffArgs []string) error {
 	for imageArg := range imageMap {
 		go func(imageName string, imageMap map[string]*pkgutil.Image) {
 			defer wg.Done()
+
+			prefixedName := processImageName(imageName)
 			ip := pkgutil.ImagePrepper{
-				Source: imageName,
+				Source: prefixedName,
 				Client: cli,
 			}
 			image, err := ip.GetImage()
@@ -102,8 +103,7 @@ func diffImages(image1Arg, image2Arg string, diffArgs []string) error {
 	req := differs.DiffRequest{*imageMap[image1Arg], *imageMap[image2Arg], diffTypes}
 	diffs, err := req.GetDiff()
 	if err != nil {
-		glog.Error(err.Error())
-		return errors.New("Could not perform image diff")
+		return fmt.Errorf("err msg: %s", err.Error())
 	}
 	glog.Info("Retrieving diffs")
 	outputResults(diffs)
@@ -116,6 +116,14 @@ func diffImages(image1Arg, image2Arg string, diffArgs []string) error {
 	return nil
 }
 
+func processImageName(imageName string) string {
+	if pkgutil.IsTar(imageName) || strings.HasPrefix(imageName, "daemon://") {
+		return imageName
+	}
+	// not a tar and not explicitly local, so force remote
+	return "remote://" + imageName
+}
+
 func init() {
 	RootCmd.AddCommand(diffCmd)
 	addSharedFlags(diffCmd)

cmd/root.go

@@ -47,7 +47,7 @@ var RootCmd = &cobra.Command{
 func NewClient() (*client.Client, error) {
 	cli, err := client.NewEnvClient()
 	if err != nil {
-		return nil, fmt.Errorf("Error getting docker client: %s", err)
+		return nil, fmt.Errorf("err msg: %s", err)
 	}
 	cli.NegotiateAPIVersion(context.Background())
 
@@ -93,7 +93,7 @@ func validateArgs(args []string, validatefxns ...validatefxn) error {
 
 func checkIfValidAnalyzer(flagtypes string) error {
 	if flagtypes == "" {
-		return nil
+		return errors.New("Please provide at least one analyzer to run")
 	}
 	analyzers := strings.Split(flagtypes, ",")
 	for _, name := range analyzers {

differs/differs.go

@@ -103,7 +103,7 @@ func GetAnalyzers(analyzeNames []string) (analyzeFuncs []Analyzer, err error) {
 		if a, exists := Analyzers[name]; exists {
 			analyzeFuncs = append(analyzeFuncs, a)
 		} else {
-			glog.Errorf("Unknown analyzer/differ specified", name)
+			glog.Errorf("Unknown analyzer/differ specified: %s", name)
 		}
 	}
 	if len(analyzeFuncs) == 0 {

pkg/util/BUILD.bazel

@@ -16,6 +16,8 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//vendor/github.com/containers/image/docker:go_default_library",
+        "//vendor/github.com/containers/image/docker/daemon:go_default_library",
+        "//vendor/github.com/containers/image/docker/reference:go_default_library",
         "//vendor/github.com/containers/image/docker/tarfile:go_default_library",
         "//vendor/github.com/containers/image/pkg/compression:go_default_library",
         "//vendor/github.com/containers/image/types:go_default_library",

pkg/util/cloud_prepper.go

@@ -20,11 +20,14 @@ import (
 	"regexp"
 
 	"github.com/containers/image/docker"
+	"github.com/containers/image/docker/reference"
 )
 
+const RemotePrefix = "remote://"
+
 // CloudPrepper prepares images sourced from a Cloud registry
 type CloudPrepper struct {
-	ImagePrepper
+	*ImagePrepper
 }
 
 func (p CloudPrepper) Name() string {
@@ -36,12 +39,12 @@ func (p CloudPrepper) GetSource() string {
 }
 
 func (p CloudPrepper) SupportsImage() bool {
-	pattern := regexp.MustCompile("^.+/.+(:.+){0,1}$")
-	image := p.ImagePrepper.Source
-	if exp := pattern.FindString(image); exp != image || CheckTar(image) {
+	daemonRegex := regexp.MustCompile(DaemonPrefix + ".*")
+	if match := daemonRegex.MatchString(p.ImagePrepper.Source); match {
 		return false
 	}
-	return true
+	_, err := reference.Parse(p.ImagePrepper.Source)
+	return (err == nil) && !IsTar(p.ImagePrepper.Source)
 }
 
 func (p CloudPrepper) GetFileSystem() (string, error) {

pkg/util/daemon_prepper.go

@@ -18,14 +18,17 @@ package util
 
 import (
 	"context"
-	"os"
-	"regexp"
+	"strings"
 
+	"github.com/containers/image/docker/daemon"
+	"github.com/containers/image/docker/reference"
 	"github.com/golang/glog"
 )
 
+const DaemonPrefix = "daemon://"
+
 type DaemonPrepper struct {
-	ImagePrepper
+	*ImagePrepper
 }
 
 func (p DaemonPrepper) Name() string {
@@ -37,21 +40,17 @@ func (p DaemonPrepper) GetSource() string {
 }
 
 func (p DaemonPrepper) SupportsImage() bool {
-	pattern := regexp.MustCompile("[a-z|0-9]{12}")
-	if exp := pattern.FindString(p.ImagePrepper.Source); exp != p.ImagePrepper.Source {
-		return false
-	}
-	return true
+	_, err := reference.Parse(strings.Replace(p.ImagePrepper.Source, DaemonPrefix, "", -1))
+	return (err != nil) && !IsTar(p.ImagePrepper.Source)
 }
 
 func (p DaemonPrepper) GetFileSystem() (string, error) {
-	tarPath, err := saveImageToTar(p.Client, p.Source, p.Source)
+	ref, err := daemon.ParseReference(p.Source)
 	if err != nil {
 		return "", err
 	}
 
-	defer os.Remove(tarPath)
-	return getImageFromTar(tarPath)
+	return getFileSystemFromReference(ref, p.Source)
 }
 
 func (p DaemonPrepper) GetConfig() (ConfigSchema, error) {

pkg/util/image_prep_utils.go

@@ -30,10 +30,10 @@ import (
 	"github.com/golang/glog"
 )
 
-var orderedPreppers = []func(ip ImagePrepper) Prepper{
-	func(ip ImagePrepper) Prepper { return DaemonPrepper{ImagePrepper: ip} },
-	func(ip ImagePrepper) Prepper { return CloudPrepper{ImagePrepper: ip} },
-	func(ip ImagePrepper) Prepper { return TarPrepper{ImagePrepper: ip} },
+var orderedPreppers = []func(ip *ImagePrepper) Prepper{
+	func(ip *ImagePrepper) Prepper { return DaemonPrepper{ImagePrepper: ip} },
+	func(ip *ImagePrepper) Prepper { return CloudPrepper{ImagePrepper: ip} },
+	func(ip *ImagePrepper) Prepper { return TarPrepper{ImagePrepper: ip} },
 }
 
 type Image struct {

pkg/util/image_prepper.go

@@ -18,6 +18,8 @@ package util
 
 import (
 	"errors"
+	"fmt"
+	"strings"
 
 	"github.com/docker/docker/client"
 	"github.com/golang/glog"
@@ -36,12 +38,42 @@ type Prepper interface {
 	SupportsImage() bool
 }
 
-func (p ImagePrepper) GetImage() (Image, error) {
+func getImage(prepper Prepper) (Image, error) {
+	imgPath, err := prepper.GetFileSystem()
+	if err != nil {
+		return Image{}, fmt.Errorf("error msg: %s", err.Error())
+	}
+
+	config, err := prepper.GetConfig()
+	if err != nil {
+		return Image{}, fmt.Errorf("error msg: %s", err.Error())
+	}
+
+	glog.Infof("Finished prepping image %s", prepper.GetSource())
+	return Image{
+		Source: prepper.GetSource(),
+		FSPath: imgPath,
+		Config: config,
+	}, nil
+}
+
+func (p *ImagePrepper) GetImage() (Image, error) {
 	glog.Infof("Starting prep for image %s", p.Source)
 	img := p.Source
 
 	var prepper Prepper
 
+	// first, respect prefixes on image names
+	if strings.HasPrefix(p.Source, "daemon://") {
+		p.Source = strings.Replace(p.Source, "daemon://", "", -1)
+		prepper = DaemonPrepper{ImagePrepper: p}
+		return getImage(prepper)
+	} else if strings.HasPrefix(p.Source, "remote://") {
+		p.Source = strings.Replace(p.Source, "remote://", "", -1)
+		prepper = CloudPrepper{ImagePrepper: p}
+		return getImage(prepper)
+	}
+
 	for _, prepperConstructor := range orderedPreppers {
 		prepper = prepperConstructor(p)
 		if prepper.SupportsImage() {

pkg/util/tar_prepper.go

@@ -29,7 +29,7 @@ import (
 )
 
 type TarPrepper struct {
-	ImagePrepper
+	*ImagePrepper
 }
 
 func (p TarPrepper) Name() string {

pkg/util/tar_utils.go

@@ -106,7 +106,9 @@ func UnTar(filename string, target string) error {
 }
 
 func IsTar(path string) bool {
-	return filepath.Ext(path) == ".tar"
+	return filepath.Ext(path) == ".tar" ||
+		filepath.Ext(path) == ".tar.gz" ||
+		filepath.Ext(path) == ".tgz"
 }
 
 func CheckTar(image string) bool {

tests/integration_test.go

@@ -20,12 +20,17 @@ package tests
 
 import (
 	"bytes"
+	"context"
 	"fmt"
 	"io/ioutil"
+	"os"
 	"os/exec"
 	"path/filepath"
 	"strings"
 	"testing"
+
+	"github.com/docker/docker/client"
+	"github.com/docker/docker/api/types"
 )
 
 const (
@@ -43,6 +48,9 @@ const (
 
 	multiBase     = "gcr.io/gcp-runtimes/multi-base"
 	multiModified = "gcr.io/gcp-runtimes/multi-modified"
+
+	multiBaseLocal     = "daemon://gcr.io/gcp-runtimes/multi-base"
+	multiModifiedLocal = "daemon://gcr.io/gcp-runtimes/multi-modified"
 )
 
 type ContainerDiffRunner struct {
@@ -115,6 +123,14 @@ func TestDiffAndAnalysis(t *testing.T) {
 			differFlags:  []string{"--types=node,pip,apt"},
 			expectedFile: "multi_diff_expected.json",
 		},
+		{
+			description:  "multi differ local",
+			subcommand:   "diff",
+			imageA:       multiBaseLocal,
+			imageB:       multiModifiedLocal,
+			differFlags:  []string{"--types=node,pip,apt"},
+			expectedFile: "multi_diff_expected.json",
+		},
 		{
 			description:  "history differ",
 			subcommand:   "diff",
@@ -185,3 +201,20 @@ func TestDiffAndAnalysis(t *testing.T) {
 		})
 	}
 }
+
+func TestMain(m *testing.M) {
+	// setup
+	ctx := context.Background()
+	cli, _ := client.NewEnvClient()
+	closer, err := cli.ImagePull(ctx, multiBase, types.ImagePullOptions{})
+	if err != nil {
+		os.Exit(1)
+	}
+	closer.Close()
+	closer, err = cli.ImagePull(ctx, multiModified, types.ImagePullOptions{})
+	if err != nil {
+		os.Exit(1)
+	}
+	closer.Close()
+	os.Exit(m.Run())
+}