Merge branch 'quiet-flag' of https://github.com/priyawadhwa/container-diff into quiet-flag

Author: Priya Wadhwa

cmd/analyze.go

@@ -38,6 +38,7 @@ var analyzeCmd = &cobra.Command{
 		return nil
 	},
 	Run: func(cmd *cobra.Command, args []string) {
+		pkgutil.SetQuiet(quiet)
 		if err := analyzeImage(args[0], types); err != nil {
 			logrus.Error(err)
 			os.Exit(1)
@@ -86,7 +87,7 @@ func analyzeImage(imageName string, analyzerArgs []string) error {
 		return fmt.Errorf("Error performing image analysis: %s", err)
 	}
 
-	fmt.Fprintln(os.Stderr, "Retrieving analyses")
+	pkgutil.PrintToStdErr("Retrieving analyses")
 	outputResults(analyses)
 
 	if save {

cmd/diff.go

@@ -42,6 +42,7 @@ var diffCmd = &cobra.Command{
 		return nil
 	},
 	Run: func(cmd *cobra.Command, args []string) {
+		pkgutil.SetQuiet(quiet)
 		if err := diffImages(args[0], args[1], types); err != nil {
 			logrus.Error(err)
 			os.Exit(1)
@@ -82,7 +83,7 @@ func diffImages(image1Arg, image2Arg string, diffArgs []string) error {
 	var wg sync.WaitGroup
 	wg.Add(2)
 
-	fmt.Fprintf(os.Stderr, "Starting diff on images %s and %s, using differs: %s\n", image1Arg, image2Arg, diffArgs)
+	pkgutil.PrintToStdErr("Starting diff on images %s and %s, using differs: %s\n", image1Arg, image2Arg, diffArgs)
 
 	imageMap := map[string]*pkgutil.Image{
 		image1Arg: {},
@@ -112,7 +113,7 @@ func diffImages(image1Arg, image2Arg string, diffArgs []string) error {
 		defer pkgutil.CleanupImage(*imageMap[image2Arg])
 	}
 
-	fmt.Fprintln(os.Stderr, "Computing diffs")
+	pkgutil.PrintToStdErr("Computing diffs")
 	req := differs.DiffRequest{
 		Image1:    *imageMap[image1Arg],
 		Image2:    *imageMap[image2Arg],
@@ -124,7 +125,7 @@ func diffImages(image1Arg, image2Arg string, diffArgs []string) error {
 	outputResults(diffs)
 
 	if filename != "" {
-		fmt.Fprintln(os.Stderr, "Computing filename diffs")
+		pkgutil.PrintToStdErr("Computing filename diffs")
 		err := diffFile(imageMap[image1Arg], imageMap[image2Arg])
 		if err != nil {
 			return err

cmd/root.go

@@ -39,6 +39,7 @@ var json bool
 var save bool
 var types diffTypes
 var noCache bool
+var quiet bool
 
 var LogLevel string
 
@@ -209,6 +210,7 @@ func (d *diffTypes) Type() string {
 
 func addSharedFlags(cmd *cobra.Command) {
 	cmd.Flags().BoolVarP(&json, "json", "j", false, "JSON Output defines if the diff should be returned in a human readable format (false) or a JSON (true).")
+	cmd.Flags().BoolVarP(&quiet, "quiet", "q", false, "Suppress output to stderr.")
 	cmd.Flags().VarP(&types, "type", "t", "This flag sets the list of analyzer types to use. Set it repeatedly to use multiple 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.")

differs/rpm_diff.go

@@ -112,7 +112,7 @@ func rpmDataFromContainer(image pkgutil.Image) (map[string]util.PackageInfo, err
 
 		archive, err := generateNewArchive(imageName)
 		if err != nil {
-			fmt.Println(err.Error())
+			logrus.Errorf(err.Error())
 		}
 		defer os.Remove(archive)
 

pkg/util/cmd_utils.go

@@ -0,0 +1,34 @@
+/*
+Copyright 2017 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.
+*/
+
+package util
+
+import (
+	"fmt"
+	"os"
+)
+
+var quiet = false
+
+func PrintToStdErr(output string, vars ...interface{}) {
+	if !quiet {
+		fmt.Fprintf(os.Stderr, output, vars...)
+	}
+}
+
+func SetQuiet(q bool) {
+	quiet = q
+}

pkg/util/image_prep_utils.go

@@ -20,7 +20,6 @@ import (
 	"archive/tar"
 	"encoding/json"
 	"errors"
-	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
@@ -100,7 +99,7 @@ type ConfigSchema struct {
 }
 
 func getImage(p Prepper) (Image, error) {
-	fmt.Fprintf(os.Stderr, "Retrieving image %s from source %s\n", p.GetSource(), p.Name())
+	PrintToStdErr("Retrieving image %s from source %s\n", p.GetSource(), p.Name())
 	imgPath, err := p.GetFileSystem()
 	if err != nil {
 		return Image{}, err