Another bunch of warning cleanups

cmd/containers-storage/container.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"encoding/json"
 	"fmt"
 	"io"
 	"os"
@@ -14,11 +13,10 @@ var (
 	paramContainerDataFile = ""
 )
 
-func container(flags *mflag.FlagSet, action string, m storage.Store, args []string) int {
+func container(flags *mflag.FlagSet, action string, m storage.Store, args []string) (int, error) {
 	images, err := m.Images()
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-		return 1
+		return 1, err
 	}
 	matches := []*storage.Container{}
 	for _, arg := range args {
@@ -27,7 +25,9 @@ func container(flags *mflag.FlagSet, action string, m storage.Store, args []stri
 		}
 	}
 	if jsonOutput {
-		json.NewEncoder(os.Stdout).Encode(matches)
+		if _, err := outputJSON(matches); err != nil {
+			return 1, err
+		}
 	} else {
 		for _, container := range matches {
 			fmt.Printf("ID: %s\n", container.ID)
@@ -56,140 +56,125 @@ func container(flags *mflag.FlagSet, action string, m storage.Store, args []stri
 		}
 	}
 	if len(matches) != len(args) {
-		return 1
+		return 1, nil
 	}
-	return 0
+	return 0, nil
 }
 
-func listContainerBigData(flags *mflag.FlagSet, action string, m storage.Store, args []string) int {
+func listContainerBigData(flags *mflag.FlagSet, action string, m storage.Store, args []string) (int, error) {
 	container, err := m.Container(args[0])
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-		return 1
+		return 1, err
 	}
 	d, err := m.ListContainerBigData(container.ID)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-		return 1
+		return 1, err
 	}
 	if jsonOutput {
-		json.NewEncoder(os.Stdout).Encode(d)
-	} else {
-		for _, name := range d {
-			fmt.Printf("%s\n", name)
-		}
+		return outputJSON(d)
 	}
-	return 0
+	for _, name := range d {
+		fmt.Printf("%s\n", name)
+	}
+	return 0, nil
 }
 
-func getContainerBigData(flags *mflag.FlagSet, action string, m storage.Store, args []string) int {
+func getContainerBigData(flags *mflag.FlagSet, action string, m storage.Store, args []string) (int, error) {
 	container, err := m.Container(args[0])
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-		return 1
+		return 1, err
 	}
 	output := os.Stdout
 	if paramContainerDataFile != "" {
 		f, err := os.Create(paramContainerDataFile)
 		if err != nil {
-			fmt.Fprintf(os.Stderr, "%v\n", err)
-			return 1
+			return 1, err
 		}
 		output = f
 	}
 	b, err := m.ContainerBigData(container.ID, args[1])
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-		return 1
+		return 1, err
+	}
+	if _, err := output.Write(b); err != nil {
+		return 1, err
 	}
-	output.Write(b)
 	output.Close()
-	return 0
+	return 0, nil
 }
 
-func getContainerBigDataSize(flags *mflag.FlagSet, action string, m storage.Store, args []string) int {
+func getContainerBigDataSize(flags *mflag.FlagSet, action string, m storage.Store, args []string) (int, error) {
 	container, err := m.Container(args[0])
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-		return 1
+		return 1, err
 	}
 	size, err := m.ContainerBigDataSize(container.ID, args[1])
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-		return 1
+		return 1, err
 	}
 	fmt.Fprintf(os.Stdout, "%d\n", size)
-	return 0
+	return 0, nil
 }
 
-func getContainerBigDataDigest(flags *mflag.FlagSet, action string, m storage.Store, args []string) int {
+func getContainerBigDataDigest(flags *mflag.FlagSet, action string, m storage.Store, args []string) (int, error) {
 	container, err := m.Container(args[0])
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-		return 1
+		return 1, err
 	}
 	d, err := m.ContainerBigDataDigest(container.ID, args[1])
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-		return 1
+		return 1, err
 	}
-	if d.Validate() != nil {
-		fmt.Fprintf(os.Stderr, "%v\n", d.Validate())
-		return 1
+	if err := d.Validate(); err != nil {
+		return 1, err
 	}
 	fmt.Fprintf(os.Stdout, "%s\n", d.String())
-	return 0
+	return 0, nil
 }
 
-func setContainerBigData(flags *mflag.FlagSet, action string, m storage.Store, args []string) int {
+func setContainerBigData(flags *mflag.FlagSet, action string, m storage.Store, args []string) (int, error) {
 	container, err := m.Container(args[0])
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-		return 1
+		return 1, err
 	}
 	input := os.Stdin
 	if paramContainerDataFile != "" {
 		f, err := os.Open(paramContainerDataFile)
 		if err != nil {
-			fmt.Fprintf(os.Stderr, "%v\n", err)
-			return 1
+			return 1, err
 		}
 		input = f
 	}
 	b, err := io.ReadAll(input)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%v\n", err)
-		return 1
+		return 1, err
 	}
 	err = m.SetContainerBigData(container.ID, args[1], b)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-		return 1
+		return 1, err
 	}
-	return 0
+	return 0, nil
 }
 
-func getContainerDir(flags *mflag.FlagSet, action string, m storage.Store, args []string) int {
+func getContainerDir(flags *mflag.FlagSet, action string, m storage.Store, args []string) (int, error) {
 	path, err := m.ContainerDirectory(args[0])
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-		return 1
+		return 1, err
 	}
 	fmt.Printf("%s\n", path)
-	return 0
+	return 0, nil
 }
 
-func getContainerRunDir(flags *mflag.FlagSet, action string, m storage.Store, args []string) int {
+func getContainerRunDir(flags *mflag.FlagSet, action string, m storage.Store, args []string) (int, error) {
 	path, err := m.ContainerRunDirectory(args[0])
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-		return 1
+		return 1, err
 	}
 	fmt.Printf("%s\n", path)
-	return 0
+	return 0, nil
 }
 
-func containerParentOwners(flags *mflag.FlagSet, action string, m storage.Store, args []string) int {
+func containerParentOwners(flags *mflag.FlagSet, action string, m storage.Store, args []string) (int, error) {
 	matched := []*storage.Container{}
 	for _, arg := range args {
 		if container, err := m.Container(arg); err == nil {
@@ -199,8 +184,7 @@ func containerParentOwners(flags *mflag.FlagSet, action string, m storage.Store,
 	for _, container := range matched {
 		uids, gids, err := m.ContainerParentOwners(container.ID)
 		if err != nil {
-			fmt.Fprintf(os.Stderr, "ContainerParentOwner: %+v\n", err)
-			return 1
+			return 1, fmt.Errorf("ContainerParentOwner: %+v", err)
 		}
 		if jsonOutput {
 			mappings := struct {
@@ -212,17 +196,19 @@ func containerParentOwners(flags *mflag.FlagSet, action string, m storage.Store,
 				UIDs: uids,
 				GIDs: gids,
 			}
-			json.NewEncoder(os.Stdout).Encode(mappings)
+			if _, err := outputJSON(mappings); err != nil {
+				return 1, err
+			}
 		} else {
 			fmt.Printf("ID: %s\n", container.ID)
 			fmt.Printf("UIDs: %v\n", uids)
 			fmt.Printf("GIDs: %v\n", gids)
 		}
 	}
 	if len(matched) != len(args) {
-		return 1
+		return 1, nil
 	}
-	return 0
+	return 0, nil
 }
 
 func init() {

cmd/containers-storage/containers.go

@@ -1,34 +1,30 @@
 package main
 
 import (
-	"encoding/json"
 	"fmt"
-	"os"
 
 	"github.com/containers/storage"
 	"github.com/containers/storage/pkg/mflag"
 )
 
-func containers(flags *mflag.FlagSet, action string, m storage.Store, args []string) int {
+func containers(flags *mflag.FlagSet, action string, m storage.Store, args []string) (int, error) {
 	containers, err := m.Containers()
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-		return 1
+		return 1, err
 	}
 	if jsonOutput {
-		json.NewEncoder(os.Stdout).Encode(containers)
-	} else {
-		for _, container := range containers {
-			fmt.Printf("%s\n", container.ID)
-			for _, name := range container.Names {
-				fmt.Printf("\tname: %s\n", name)
-			}
-			for _, name := range container.BigDataNames {
-				fmt.Printf("\tdata: %s\n", name)
-			}
+		return outputJSON(containers)
+	}
+	for _, container := range containers {
+		fmt.Printf("%s\n", container.ID)
+		for _, name := range container.Names {
+			fmt.Printf("\tname: %s\n", name)
+		}
+		for _, name := range container.BigDataNames {
+			fmt.Printf("\tdata: %s\n", name)
 		}
 	}
-	return 0
+	return 0, nil
 }
 
 func init() {

cmd/containers-storage/copy.go

@@ -17,11 +17,11 @@ var (
 	chownOptions = ""
 )
 
-func copyContent(flags *mflag.FlagSet, action string, m storage.Store, args []string) int {
+func copyContent(flags *mflag.FlagSet, action string, m storage.Store, args []string) (int, error) {
 	var untarIDMappings *idtools.IDMappings
 	var chownOpts *idtools.IDPair
 	if len(args) < 1 {
-		return 1
+		return 1, nil
 	}
 	if len(chownOptions) > 0 {
 		chownParts := strings.SplitN(chownOptions, ":", 2)
@@ -30,36 +30,36 @@ func copyContent(flags *mflag.FlagSet, action string, m storage.Store, args []st
 		}
 		uid, err := strconv.ParseUint(chownParts[0], 10, 32)
 		if err != nil {
-			fmt.Fprintf(os.Stderr, "error %q as a numeric UID: %v", chownParts[0], err)
-			return 1
+			return 1, fmt.Errorf("error %q as a numeric UID: %v", chownParts[0], err)
 		}
 		gid, err := strconv.ParseUint(chownParts[1], 10, 32)
 		if err != nil {
-			fmt.Fprintf(os.Stderr, "error %q as a numeric GID: %v", chownParts[1], err)
-			return 1
+			return 1, fmt.Errorf("error %q as a numeric GID: %v", chownParts[1], err)
 		}
 		chownOpts = &idtools.IDPair{UID: int(uid), GID: int(gid)}
 	}
 	target := args[len(args)-1]
 	if strings.Contains(target, ":") {
 		targetParts := strings.SplitN(target, ":", 2)
 		if len(targetParts) != 2 {
-			fmt.Fprintf(os.Stderr, "error parsing target location %q: only one part\n", target)
-			return 1
+			return 1, fmt.Errorf("error parsing target location %q: only one part", target)
 		}
 		targetLayer, err := m.Layer(targetParts[0])
 		if err != nil {
-			fmt.Fprintf(os.Stderr, "error finding layer %q: %+v\n", targetParts[0], err)
-			return 1
+			return 1, fmt.Errorf("error finding layer %q: %+v", targetParts[0], err)
 		}
 		untarIDMappings = idtools.NewIDMappingsFromMaps(targetLayer.UIDMap, targetLayer.GIDMap)
 		targetMount, err := m.Mount(targetLayer.ID, targetLayer.MountLabel)
 		if err != nil {
-			fmt.Fprintf(os.Stderr, "error mounting layer %q: %+v\n", targetLayer.ID, err)
-			return 1
+			return 1, fmt.Errorf("error mounting layer %q: %+v", targetLayer.ID, err)
 		}
 		target = filepath.Join(targetMount, targetParts[1])
-		defer m.Unmount(targetLayer.ID, false)
+		defer func() {
+			if _, err := m.Unmount(targetLayer.ID, false); err != nil {
+				fmt.Fprintf(os.Stderr, "error unmounting layer %q: %+v\n", targetLayer.ID, err)
+				// Does not change the exit code
+			}
+		}()
 	}
 	args = args[:len(args)-1]
 	for _, srcSpec := range args {
@@ -68,30 +68,31 @@ func copyContent(flags *mflag.FlagSet, action string, m storage.Store, args []st
 		if strings.Contains(source, ":") {
 			sourceParts := strings.SplitN(source, ":", 2)
 			if len(sourceParts) != 2 {
-				fmt.Fprintf(os.Stderr, "error parsing source location %q: only one part\n", source)
-				return 1
+				return 1, fmt.Errorf("error parsing source location %q: only one part", source)
 			}
 			sourceLayer, err := m.Layer(sourceParts[0])
 			if err != nil {
-				fmt.Fprintf(os.Stderr, "error finding layer %q: %+v\n", sourceParts[0], err)
-				return 1
+				return 1, fmt.Errorf("error finding layer %q: %+v", sourceParts[0], err)
 			}
 			tarIDMappings = idtools.NewIDMappingsFromMaps(sourceLayer.UIDMap, sourceLayer.GIDMap)
 			sourceMount, err := m.Mount(sourceLayer.ID, sourceLayer.MountLabel)
 			if err != nil {
-				fmt.Fprintf(os.Stderr, "error mounting layer %q: %+v\n", sourceLayer.ID, err)
-				return 1
+				return 1, fmt.Errorf("error mounting layer %q: %+v", sourceLayer.ID, err)
 			}
 			source = filepath.Join(sourceMount, sourceParts[1])
-			defer m.Unmount(sourceLayer.ID, false)
+			defer func() {
+				if _, err := m.Unmount(sourceLayer.ID, false); err != nil {
+					fmt.Fprintf(os.Stderr, "error unmounting layer %q: %+v\n", sourceLayer.ID, err)
+					// Does not change the exit code
+				}
+			}()
 		}
 		archiver := chrootarchive.NewArchiverWithChown(tarIDMappings, chownOpts, untarIDMappings)
 		if err := archiver.CopyWithTar(source, target); err != nil {
-			fmt.Fprintf(os.Stderr, "error copying %q to %q: %+v\n", source, target, err)
-			return 1
+			return 1, fmt.Errorf("error copying %q to %q: %+v", source, target, err)
 		}
 	}
-	return 0
+	return 0, nil
 }
 
 func init() {