Remove redundant error messages

For operations on multi containers, we printed error for each
failed container, then printed an extra message for container
names, it seems redundant.

Addresses comments:
https://github.com/docker/docker/pull/15078#discussion_r47988449

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>

api/client/kill.go

@@ -2,6 +2,7 @@ package client
 
 import (
 	"fmt"
+	"strings"
 
 	Cli "github.com/docker/docker/cli"
 	flag "github.com/docker/docker/pkg/mflag"
@@ -17,17 +18,16 @@ func (cli *DockerCli) CmdKill(args ...string) error {
 
 	cmd.ParseFlags(args, true)
 
-	var errNames []string
+	var errs []string
 	for _, name := range cmd.Args() {
 		if err := cli.client.ContainerKill(name, *signal); err != nil {
-			fmt.Fprintf(cli.err, "%s\n", err)
-			errNames = append(errNames, name)
+			errs = append(errs, fmt.Sprintf("Failed to kill container (%s): %s", name, err))
 		} else {
 			fmt.Fprintf(cli.out, "%s\n", name)
 		}
 	}
-	if len(errNames) > 0 {
-		return fmt.Errorf("Error: failed to kill containers: %v", errNames)
+	if len(errs) > 0 {
+		return fmt.Errorf("%s", strings.Join(errs, "\n"))
 	}
 	return nil
 }

api/client/pause.go

@@ -2,6 +2,7 @@ package client
 
 import (
 	"fmt"
+	"strings"
 
 	Cli "github.com/docker/docker/cli"
 	flag "github.com/docker/docker/pkg/mflag"
@@ -16,17 +17,16 @@ func (cli *DockerCli) CmdPause(args ...string) error {
 
 	cmd.ParseFlags(args, true)
 
-	var errNames []string
+	var errs []string
 	for _, name := range cmd.Args() {
 		if err := cli.client.ContainerPause(name); err != nil {
-			fmt.Fprintf(cli.err, "%s\n", err)
-			errNames = append(errNames, name)
+			errs = append(errs, fmt.Sprintf("Failed to pause container (%s): %s", name, err))
 		} else {
 			fmt.Fprintf(cli.out, "%s\n", name)
 		}
 	}
-	if len(errNames) > 0 {
-		return fmt.Errorf("Error: failed to pause containers: %v", errNames)
+	if len(errs) > 0 {
+		return fmt.Errorf("%s", strings.Join(errs, "\n"))
 	}
 	return nil
 }

api/client/restart.go

@@ -2,6 +2,7 @@ package client
 
 import (
 	"fmt"
+	"strings"
 
 	Cli "github.com/docker/docker/cli"
 	flag "github.com/docker/docker/pkg/mflag"
@@ -17,17 +18,16 @@ func (cli *DockerCli) CmdRestart(args ...string) error {
 
 	cmd.ParseFlags(args, true)
 
-	var errNames []string
+	var errs []string
 	for _, name := range cmd.Args() {
 		if err := cli.client.ContainerRestart(name, *nSeconds); err != nil {
-			fmt.Fprintf(cli.err, "%s\n", err)
-			errNames = append(errNames, name)
+			errs = append(errs, fmt.Sprintf("Failed to kill container (%s): %s", name, err))
 		} else {
 			fmt.Fprintf(cli.out, "%s\n", name)
 		}
 	}
-	if len(errNames) > 0 {
-		return fmt.Errorf("Error: failed to restart containers: %v", errNames)
+	if len(errs) > 0 {
+		return fmt.Errorf("%s", strings.Join(errs, "\n"))
 	}
 	return nil
 }

api/client/rm.go

@@ -21,7 +21,7 @@ func (cli *DockerCli) CmdRm(args ...string) error {
 
 	cmd.ParseFlags(args, true)
 
-	var errNames []string
+	var errs []string
 	for _, name := range cmd.Args() {
 		if name == "" {
 			return fmt.Errorf("Container name cannot be empty")
@@ -36,14 +36,13 @@ func (cli *DockerCli) CmdRm(args ...string) error {
 		}
 
 		if err := cli.client.ContainerRemove(options); err != nil {
-			fmt.Fprintf(cli.err, "%s\n", err)
-			errNames = append(errNames, name)
+			errs = append(errs, fmt.Sprintf("Failed to remove container (%s): %s", name, err))
 		} else {
 			fmt.Fprintf(cli.out, "%s\n", name)
 		}
 	}
-	if len(errNames) > 0 {
-		return fmt.Errorf("Error: failed to remove containers: %v", errNames)
+	if len(errs) > 0 {
+		return fmt.Errorf("%s", strings.Join(errs, "\n"))
 	}
 	return nil
 }

api/client/rmi.go

@@ -3,6 +3,7 @@ package client
 import (
 	"fmt"
 	"net/url"
+	"strings"
 
 	"github.com/docker/docker/api/types"
 	Cli "github.com/docker/docker/cli"
@@ -28,7 +29,7 @@ func (cli *DockerCli) CmdRmi(args ...string) error {
 		v.Set("noprune", "1")
 	}
 
-	var errNames []string
+	var errs []string
 	for _, name := range cmd.Args() {
 		options := types.ImageRemoveOptions{
 			ImageID:       name,
@@ -38,8 +39,7 @@ func (cli *DockerCli) CmdRmi(args ...string) error {
 
 		dels, err := cli.client.ImageRemove(options)
 		if err != nil {
-			fmt.Fprintf(cli.err, "%s\n", err)
-			errNames = append(errNames, name)
+			errs = append(errs, fmt.Sprintf("Failed to remove image (%s): %s", name, err))
 		} else {
 			for _, del := range dels {
 				if del.Deleted != "" {
@@ -50,8 +50,8 @@ func (cli *DockerCli) CmdRmi(args ...string) error {
 			}
 		}
 	}
-	if len(errNames) > 0 {
-		return fmt.Errorf("Error: failed to remove images: %v", errNames)
+	if len(errs) > 0 {
+		return fmt.Errorf("%s", strings.Join(errs, "\n"))
 	}
 	return nil
 }

api/client/stop.go

@@ -2,6 +2,7 @@ package client
 
 import (
 	"fmt"
+	"strings"
 
 	Cli "github.com/docker/docker/cli"
 	flag "github.com/docker/docker/pkg/mflag"
@@ -19,17 +20,16 @@ func (cli *DockerCli) CmdStop(args ...string) error {
 
 	cmd.ParseFlags(args, true)
 
-	var errNames []string
+	var errs []string
 	for _, name := range cmd.Args() {
 		if err := cli.client.ContainerStop(name, *nSeconds); err != nil {
-			fmt.Fprintf(cli.err, "%s\n", err)
-			errNames = append(errNames, name)
+			errs = append(errs, fmt.Sprintf("Failed to stop container (%s): %s", name, err))
 		} else {
 			fmt.Fprintf(cli.out, "%s\n", name)
 		}
 	}
-	if len(errNames) > 0 {
-		return fmt.Errorf("Error: failed to stop containers: %v", errNames)
+	if len(errs) > 0 {
+		return fmt.Errorf("%s", strings.Join(errs, "\n"))
 	}
 	return nil
 }

api/client/unpause.go

@@ -2,6 +2,7 @@ package client
 
 import (
 	"fmt"
+	"strings"
 
 	Cli "github.com/docker/docker/cli"
 	flag "github.com/docker/docker/pkg/mflag"
@@ -16,17 +17,16 @@ func (cli *DockerCli) CmdUnpause(args ...string) error {
 
 	cmd.ParseFlags(args, true)
 
-	var errNames []string
+	var errs []string
 	for _, name := range cmd.Args() {
 		if err := cli.client.ContainerUnpause(name); err != nil {
-			fmt.Fprintf(cli.err, "%s\n", err)
-			errNames = append(errNames, name)
+			errs = append(errs, fmt.Sprintf("Failed to unpause container (%s): %s", name, err))
 		} else {
 			fmt.Fprintf(cli.out, "%s\n", name)
 		}
 	}
-	if len(errNames) > 0 {
-		return fmt.Errorf("Error: failed to unpause containers: %v", errNames)
+	if len(errs) > 0 {
+		return fmt.Errorf("%s", strings.Join(errs, "\n"))
 	}
 	return nil
 }

api/client/update.go

@@ -2,6 +2,7 @@ package client
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/docker/docker/api/types/container"
 	Cli "github.com/docker/docker/cli"
@@ -86,18 +87,17 @@ func (cli *DockerCli) CmdUpdate(args ...string) error {
 	}
 
 	names := cmd.Args()
-	var errNames []string
+	var errs []string
 	for _, name := range names {
 		if err := cli.client.ContainerUpdate(name, hostConfig); err != nil {
-			fmt.Fprintf(cli.err, "%s\n", err)
-			errNames = append(errNames, name)
+			errs = append(errs, fmt.Sprintf("Failed to update container (%s): %s", name, err))
 		} else {
 			fmt.Fprintf(cli.out, "%s\n", name)
 		}
 	}
 
-	if len(errNames) > 0 {
-		return fmt.Errorf("Error: failed to update resources of containers: %v", errNames)
+	if len(errs) > 0 {
+		return fmt.Errorf("%s", strings.Join(errs, "\n"))
 	}
 
 	return nil

api/client/wait.go

@@ -2,6 +2,7 @@ package client
 
 import (
 	"fmt"
+	"strings"
 
 	Cli "github.com/docker/docker/cli"
 	flag "github.com/docker/docker/pkg/mflag"
@@ -18,18 +19,17 @@ func (cli *DockerCli) CmdWait(args ...string) error {
 
 	cmd.ParseFlags(args, true)
 
-	var errNames []string
+	var errs []string
 	for _, name := range cmd.Args() {
 		status, err := cli.client.ContainerWait(name)
 		if err != nil {
-			fmt.Fprintf(cli.err, "%s\n", err)
-			errNames = append(errNames, name)
+			errs = append(errs, fmt.Sprintf("Failed to wait container (%s): %s", name, err))
 		} else {
 			fmt.Fprintf(cli.out, "%d\n", status)
 		}
 	}
-	if len(errNames) > 0 {
-		return fmt.Errorf("Error: failed to wait containers: %v", errNames)
+	if len(errs) > 0 {
+		return fmt.Errorf("%s", strings.Join(errs, "\n"))
 	}
 	return nil
 }

integration-cli/docker_cli_rm_test.go

@@ -73,8 +73,8 @@ func (s *DockerSuite) TestRmContainerOrphaning(c *check.C) {
 func (s *DockerSuite) TestRmInvalidContainer(c *check.C) {
 	if out, _, err := dockerCmdWithError("rm", "unknown"); err == nil {
 		c.Fatal("Expected error on rm unknown container, got none")
-	} else if !strings.Contains(out, "failed to remove containers") {
-		c.Fatalf("Expected output to contain 'failed to remove containers', got %q", out)
+	} else if !strings.Contains(out, "Failed to remove container") {
+		c.Fatalf("Expected output to contain 'Failed to remove container', got %q", out)
 	}
 }