Merge pull request #252 from davidcassany/add_rpmlayer_differ

Add rpmlayer differ

Author: nkubala

cmd/root.go

@@ -60,8 +60,6 @@ const (
 	RemotePrefix = "remote://"
 )
 
-var layerAnalyzers = [...]string{"layer", "aptlayer"}
-
 var RootCmd = &cobra.Command{
 	Use:   "container-diff",
 	Short: "container-diff is a tool for analyzing and comparing container images",
@@ -277,7 +275,7 @@ func getExtractPathForName(name string) (string, error) {
 
 func includeLayers() bool {
 	for _, t := range types {
-		for _, a := range layerAnalyzers {
+		for _, a := range differs.LayerAnalyzers {
 			if t == a {
 				return true
 			}

differs/differs.go

@@ -24,6 +24,17 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+const historyAnalyzer = "history"
+const metadataAnalyzer = "metadata"
+const fileAnalyzer = "file"
+const layerAnalyzer = "layer"
+const aptAnalyzer = "apt"
+const aptLayerAnalyzer = "aptlayer"
+const rpmAnalyzer = "rpm"
+const rpmLayerAnalyzer = "rpmlayer"
+const pipAnalyzer = "pip"
+const nodeAnalyzer = "node"
+
 type DiffRequest struct {
 	Image1    pkgutil.Image
 	Image2    pkgutil.Image
@@ -42,17 +53,20 @@ type Analyzer interface {
 }
 
 var Analyzers = map[string]Analyzer{
-	"history":  HistoryAnalyzer{},
-	"metadata": MetadataAnalyzer{},
-	"file":     FileAnalyzer{},
-	"layer":    FileLayerAnalyzer{},
-	"apt":      AptAnalyzer{},
-	"aptlayer": AptLayerAnalyzer{},
-	"rpm":      RPMAnalyzer{},
-	"pip":      PipAnalyzer{},
-	"node":     NodeAnalyzer{},
+	historyAnalyzer:  HistoryAnalyzer{},
+	metadataAnalyzer: MetadataAnalyzer{},
+	fileAnalyzer:     FileAnalyzer{},
+	layerAnalyzer:    FileLayerAnalyzer{},
+	aptAnalyzer:      AptAnalyzer{},
+	aptLayerAnalyzer: AptLayerAnalyzer{},
+	rpmAnalyzer:      RPMAnalyzer{},
+	rpmLayerAnalyzer: RPMLayerAnalyzer{},
+	pipAnalyzer:      PipAnalyzer{},
+	nodeAnalyzer:     NodeAnalyzer{},
 }
 
+var LayerAnalyzers = [...]string{layerAnalyzer, aptLayerAnalyzer, rpmLayerAnalyzer}
+
 func (req DiffRequest) GetDiff() (map[string]util.Result, error) {
 	img1 := req.Image1
 	img2 := req.Image2

differs/rpm_diff.go

@@ -34,6 +34,8 @@ import (
 	"github.com/google/go-containerregistry/pkg/name"
 	"github.com/google/go-containerregistry/pkg/v1"
 	"github.com/google/go-containerregistry/pkg/v1/daemon"
+	"github.com/google/go-containerregistry/pkg/v1/mutate"
+	"github.com/google/go-containerregistry/pkg/v1/random"
 
 	pkgutil "github.com/GoogleContainerTools/container-diff/pkg/util"
 	"github.com/GoogleContainerTools/container-diff/util"
@@ -100,39 +102,31 @@ func (a RPMAnalyzer) getPackages(image pkgutil.Image) (map[string]util.PackageIn
 
 	packages, err := rpmDataFromImageFS(image)
 	if err != nil {
-		logrus.Info("Running RPM binary from image in a container")
-		return rpmDataFromContainer(image)
+		logrus.Info("Couldn't retrieve RPM data from extracted filesystem; running query in container")
+		return rpmDataFromContainer(image.Image)
 	}
 	return packages, err
 }
 
 // rpmDataFromImageFS runs a local rpm binary, if any, to query the image
 // rpmdb and returns a map of installed packages.
 func rpmDataFromImageFS(image pkgutil.Image) (map[string]util.PackageInfo, error) {
-	packages := make(map[string]util.PackageInfo)
-	// Check there is an executable rpm tool in host
-	if err := exec.Command("rpm", "--version").Run(); err != nil {
-		logrus.Warn("No RPM binary in host")
-		return packages, err
-	}
-	dbPath, err := rpmDBPath(image.FSPath)
+	dbPath, err := rpmEnvCheck(image.FSPath)
 	if err != nil {
 		logrus.Warnf("Couldn't find RPM database: %s", err.Error())
-		return packages, err
+		return nil, err
 	}
-	cmdArgs := append([]string{"--root", image.FSPath, "--dbpath", dbPath}, rpmCmd[1:]...)
-	out, err := exec.Command(rpmCmd[0], cmdArgs...).Output()
-	if err != nil {
-		logrus.Warnf("RPM call failed: %s", err.Error())
-		return packages, err
-	}
-	output := strings.Split(string(out), "\n")
-	return parsePackageData(output)
+	return rpmDataFromFS(image.FSPath, dbPath)
 }
 
-// rpmDBPath tries to get the RPM database path from the /usr/lib/rpm/macros
-// file in the image rootfs.
-func rpmDBPath(rootFSPath string) (string, error) {
+// rpmEnvCheck checks there is an rpm binary in the host and tries to
+// get the RPM database path from the /usr/lib/rpm/macros file in the
+// image rootfs
+func rpmEnvCheck(rootFSPath string) (string, error) {
+	if err := exec.Command("rpm", "--version").Run(); err != nil {
+		logrus.Warn("No RPM binary in host")
+		return "", err
+	}
 	imgMacrosFile, err := os.Open(filepath.Join(rootFSPath, rpmMacros))
 	if err != nil {
 		return "", err
@@ -164,7 +158,7 @@ func rpmDBPath(rootFSPath string) (string, error) {
 
 // rpmDataFromContainer runs image in a container, queries the data of
 // installed rpm packages and returns a map of packages.
-func rpmDataFromContainer(image pkgutil.Image) (map[string]util.PackageInfo, error) {
+func rpmDataFromContainer(image v1.Image) (map[string]util.PackageInfo, error) {
 	packages := make(map[string]util.PackageInfo)
 
 	client, err := godocker.NewClientFromEnv()
@@ -175,7 +169,7 @@ func rpmDataFromContainer(image pkgutil.Image) (map[string]util.PackageInfo, err
 		return packages, err
 	}
 
-	imageName, err := loadImageToDaemon(image.Image)
+	imageName, err := loadImageToDaemon(image)
 
 	if err != nil {
 		return packages, fmt.Errorf("Error loading image: %s", err)
@@ -364,3 +358,120 @@ func unlock() error {
 	daemonMutex.Unlock()
 	return nil
 }
+
+type RPMLayerAnalyzer struct {
+}
+
+// Name returns the name of the analyzer.
+func (a RPMLayerAnalyzer) Name() string {
+	return "RPMLayerAnalyzer"
+}
+
+// Diff compares the installed rpm packages of image1 and image2 for each layer
+func (a RPMLayerAnalyzer) Diff(image1, image2 pkgutil.Image) (util.Result, error) {
+	diff, err := singleVersionLayerDiff(image1, image2, a)
+	return diff, err
+}
+
+// Analyze collects information of the installed rpm packages on each layer
+func (a RPMLayerAnalyzer) Analyze(image pkgutil.Image) (util.Result, error) {
+	analysis, err := singleVersionLayerAnalysis(image, a)
+	return analysis, err
+}
+
+// getPackages returns an array of maps of installed rpm packages on each layer
+func (a RPMLayerAnalyzer) getPackages(image pkgutil.Image) ([]map[string]util.PackageInfo, error) {
+	path := image.FSPath
+	var packages []map[string]util.PackageInfo
+	if _, err := os.Stat(path); err != nil {
+		// invalid image directory path
+		return packages, err
+	}
+
+	// try to find the rpm binary in bin/ or usr/bin/
+	rpmBinary := filepath.Join(path, "bin/rpm")
+	if _, err := os.Stat(rpmBinary); err != nil {
+		rpmBinary = filepath.Join(path, "usr/bin/rpm")
+		if _, err = os.Stat(rpmBinary); err != nil {
+			logrus.Errorf("Could not detect RPM binary in unpacked image %s", image.Source)
+			return packages, nil
+		}
+	}
+
+	packages, err := rpmDataFromLayerFS(image)
+	if err != nil {
+		logrus.Info("Couldn't retrieve RPM data from extracted filesystem; running query in container")
+		return rpmDataFromLayeredContainers(image.Image)
+	}
+	return packages, err
+}
+
+// rpmDataFromLayerFS runs a local rpm binary, if any, to query the layer
+// rpmdb and returns an array of maps of installed packages.
+func rpmDataFromLayerFS(image pkgutil.Image) ([]map[string]util.PackageInfo, error) {
+	var packages []map[string]util.PackageInfo
+	dbPath, err := rpmEnvCheck(image.FSPath)
+	if err != nil {
+		logrus.Warnf("Couldn't find RPM database: %s", err.Error())
+		return packages, err
+	}
+	for _, layer := range image.Layers {
+		layerPackages, err := rpmDataFromFS(layer.FSPath, dbPath)
+		if err != nil {
+			return packages, err
+		}
+		packages = append(packages, layerPackages)
+	}
+
+	return packages, nil
+}
+
+// rpmDataFromFS runs a local rpm binary to query the image
+// rpmdb and returns a map of installed packages.
+func rpmDataFromFS(fsPath string, dbPath string) (map[string]util.PackageInfo, error) {
+	packages := make(map[string]util.PackageInfo)
+	if _, err := os.Stat(filepath.Join(fsPath, dbPath)); err == nil {
+		cmdArgs := append([]string{"--root", fsPath, "--dbpath", dbPath}, rpmCmd[1:]...)
+		out, err := exec.Command(rpmCmd[0], cmdArgs...).Output()
+		if err != nil {
+			logrus.Warnf("RPM call failed: %s", err.Error())
+			return packages, err
+		}
+		output := strings.Split(string(out), "\n")
+		packages, err := parsePackageData(output)
+		if err != nil {
+			return packages, err
+		}
+	}
+	return packages, nil
+}
+
+// rpmDataFromLayeredContainers runs a tmp image in a container for each layer,
+// queries the data of installed rpm packages and returns an array of maps of
+// packages.
+func rpmDataFromLayeredContainers(image v1.Image) ([]map[string]util.PackageInfo, error) {
+	var packages []map[string]util.PackageInfo
+	tmpImage, err := random.Image(0, 0)
+	if err != nil {
+		return packages, err
+	}
+	layers, err := image.Layers()
+	if err != nil {
+		return packages, err
+	}
+	// Append layers one by one to an empty image and query rpm
+	// database on each iteration
+	for _, layer := range layers {
+		tmpImage, err = mutate.AppendLayers(tmpImage, layer)
+		if err != nil {
+			return packages, err
+		}
+		layerPackages, err := rpmDataFromContainer(tmpImage)
+		if err != nil {
+			return packages, err
+		}
+		packages = append(packages, layerPackages)
+	}
+
+	return packages, nil
+}