Diff by filename

Author: Priya Wadhwa

cmd/analyze.go

@@ -36,6 +36,9 @@ var analyzeCmd = &cobra.Command{
 		if err := validateArgs(args, checkAnalyzeArgNum); err != nil {
 			return err
 		}
+		if err := checkAnalyzeFilenameFlag(); err != nil {
+			return err
+		}
 		if err := checkIfValidAnalyzer(types); err != nil {
 			return err
 		}
@@ -56,6 +59,13 @@ func checkAnalyzeArgNum(args []string) error {
 	return nil
 }
 
+func checkAnalyzeFilenameFlag() error {
+	if filename != "" {
+		return errors.New("please remove --filename flag, incompatible with analyze")
+	}
+	return nil
+}
+
 func analyzeImage(imageName string, analyzerArgs []string) error {
 	analyzeTypes, err := differs.GetAnalyzers(analyzerArgs)
 	if err != nil {

cmd/diff.go

@@ -19,14 +19,14 @@ package cmd
 import (
 	"errors"
 	"fmt"
-	"os"
-	"strings"
-	"sync"
-
 	"github.com/GoogleCloudPlatform/container-diff/differs"
 	pkgutil "github.com/GoogleCloudPlatform/container-diff/pkg/util"
+	"github.com/GoogleCloudPlatform/container-diff/util"
 	"github.com/golang/glog"
 	"github.com/spf13/cobra"
+	"os"
+	"strings"
+	"sync"
 )
 
 var diffCmd = &cobra.Command{
@@ -43,7 +43,8 @@ var diffCmd = &cobra.Command{
 		return nil
 	},
 	Run: func(cmd *cobra.Command, args []string) {
-		if err := diffImages(args[0], args[1], strings.Split(types, ",")); err != nil {
+		typesFlag := checkIfTypesFlagSet(cmd)
+		if err := diffImages(args[0], args[1], strings.Split(types, ","), typesFlag); err != nil {
 			glog.Error(err)
 			os.Exit(1)
 		}
@@ -57,7 +58,7 @@ func checkDiffArgNum(args []string) error {
 	return nil
 }
 
-func diffImages(image1Arg, image2Arg string, diffArgs []string) error {
+func diffImages(image1Arg, image2Arg string, diffArgs []string, typesFlag bool) error {
 	diffTypes, err := differs.GetAnalyzers(diffArgs)
 	if err != nil {
 		return err
@@ -106,6 +107,17 @@ func diffImages(image1Arg, image2Arg string, diffArgs []string) error {
 	if err != nil {
 		return fmt.Errorf("Could not retrieve diff: %s", err)
 	}
+
+	if filename != "" {
+		err := diffFile(imageMap, image1Arg, image2Arg)
+		if err != nil {
+			return err
+		}
+		if !typesFlag {
+			return nil
+		}
+	}
+
 	glog.Info("Retrieving diffs")
 	outputResults(diffs)
 
@@ -116,6 +128,20 @@ func diffImages(image1Arg, image2Arg string, diffArgs []string) error {
 	return nil
 }
 
+func diffFile(imageMap map[string]*pkgutil.Image, image1Arg, image2Arg string) error {
+
+	image1FilePath := imageMap[image1Arg].FSPath + filename
+	image2FilePath := imageMap[image2Arg].FSPath + filename
+
+	diff, err := util.DiffFile(image1FilePath, image2FilePath, image1Arg, image2Arg)
+	if err != nil {
+		return err
+	}
+	diff.Filename = filename
+	util.TemplateOutput(diff, "FileNameDiff")
+	return nil
+}
+
 func init() {
 	RootCmd.AddCommand(diffCmd)
 	addSharedFlags(diffCmd)

cmd/root.go

@@ -35,6 +35,7 @@ import (
 var json bool
 var save bool
 var types string
+var filename string
 
 type validatefxn func(args []string) error
 
@@ -106,6 +107,11 @@ func checkIfValidAnalyzer(flagtypes string) error {
 	return nil
 }
 
+func checkIfTypesFlagSet(cmd *cobra.Command) bool {
+	flag := cmd.Flags().Lookup("types")
+	return flag.Changed
+}
+
 func getPrepperForImage(image string) (pkgutil.Prepper, error) {
 	cli, err := client.NewEnvClient()
 	if err != nil {
@@ -139,4 +145,5 @@ func addSharedFlags(cmd *cobra.Command) {
 	cmd.Flags().StringVarP(&types, "types", "t", "apt", "This flag sets the list of analyzer types to use.  It expects a comma separated list of supported analyzers.")
 	cmd.Flags().BoolVarP(&save, "save", "s", false, "Set this flag to save rather than remove the final image filesystems on exit.")
 	cmd.Flags().BoolVarP(&util.SortSize, "order", "o", false, "Set this flag to sort any file/package results by descending size. Otherwise, they will be sorted by name.")
+	cmd.Flags().StringVarP(&filename, "filename", "f", "", "View the diff of a file in both containers (can only be used with container-diff diff)")
 }

pkg/util/fs_utils.go

@@ -18,6 +18,7 @@ package util
 
 import (
 	"bytes"
+	"errors"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -53,6 +54,24 @@ func GetSize(path string) int64 {
 	return stat.Size()
 }
 
+//GetFileContents returns the contents of a file at the specified path
+func GetFileContents(path string) ([]string, error) {
+	stat, err := os.Stat(path)
+	if err != nil {
+		return nil, err
+	}
+
+	if stat.IsDir() {
+		return nil, errors.New("--filename is a directory, not a file")
+	}
+	contents, err := ioutil.ReadFile(path)
+
+	if err != nil {
+		return nil, err
+	}
+	return []string{string(contents)}, nil
+}
+
 func getDirectorySize(path string) (int64, error) {
 	var size int64
 	err := filepath.Walk(path, func(_ string, info os.FileInfo, err error) error {

util/diff_utils.go

@@ -33,6 +33,11 @@ type DirDiff struct {
 	Mods []EntryDiff
 }
 
+type FileNameDiff struct {
+	Filename string
+	Diff     string
+}
+
 type EntryDiff struct {
 	Name  string
 	Size1 int64
@@ -117,6 +122,36 @@ func DiffDirectory(d1, d2 pkgutil.Directory) (DirDiff, bool) {
 	return DirDiff{addedEntries, deletedEntries, modifiedEntries}, same
 }
 
+//DiffFile diffs within a file
+func DiffFile(path1, path2, image1, image2 string) (FileNameDiff, error) {
+
+	var result FileNameDiff
+
+	image1Contents, err := pkgutil.GetFileContents(path1)
+	if err != nil {
+		return result, err
+	}
+	image2Contents, err := pkgutil.GetFileContents(path2)
+
+	if err != nil {
+		return result, err
+	}
+
+	diff := difflib.UnifiedDiff{
+		A:        image1Contents,
+		B:        image2Contents,
+		FromFile: image1,
+		ToFile:   image2,
+	}
+
+	text, err := difflib.GetUnifiedDiffString(diff)
+
+	if err != nil {
+		return result, err
+	}
+	return FileNameDiff{Diff: text}, nil
+}
+
 // Checks for content differences between files of the same name from different directories
 func GetModifiedEntries(d1, d2 pkgutil.Directory) []string {
 	d1files := d1.Content

util/format_utils.go

@@ -20,10 +20,10 @@ import (
 	"bufio"
 	"encoding/json"
 	"errors"
-	"html/template"
 	"os"
 	"strings"
 	"text/tabwriter"
+	"text/template"
 
 	"github.com/golang/glog"
 )
@@ -33,6 +33,7 @@ var templates = map[string]string{
 	"MultiVersionPackageDiff":     MultiVersionDiffOutput,
 	"HistDiff":                    HistoryDiffOutput,
 	"DirDiff":                     FSDiffOutput,
+	"FileNameDiff":                FilenameDiffOutput,
 	"ListAnalyze":                 ListAnalysisOutput,
 	"FileAnalyze":                 FileAnalysisOutput,
 	"MultiVersionPackageAnalyze":  MultiVersionPackageOutput,

util/template_utils.go

@@ -65,6 +65,11 @@ Docker history lines found only in {{.Image1}}:{{if not .Diff.Adds}} None{{else}
 
 Docker history lines found only in {{.Image2}}:{{if not .Diff.Dels}} None{{else}}{{block "list2" .Diff.Dels}}{{"\n"}}{{range .}}{{print "-" .}}{{"\n"}}{{end}}{{end}}{{end}}
 `
+const FilenameDiffOutput = `
+-----Diff of {{.Filename}}-----
+
+{{.Diff}}
+`
 
 const ListAnalysisOutput = `
 -----{{.AnalyzeType}}-----