refactor: remove all calls to common.NewShellCmd

At this point, the only usage of go-sh should be by plugin trigger calls.

plugins/builder/functions.go

@@ -1,8 +1,7 @@
 package builder
 
 import (
-	"bytes"
+	"fmt"
-	"errors"
 	"os"
 	"path"
 	"strings"
@@ -11,25 +10,18 @@ import (
 )
 
 func listImagesByImageRepo(imageRepo string) ([]string, error) {
-	command := []string{
+	result, err := common.CallExecCommand(common.ExecCommandInput{
-		common.DockerBin(),
+		Command: common.DockerBin(),
-		"image",
+		Args:    []string{"image", "ls", "--quiet", imageRepo},
-		"ls",
+	})
-		"--quiet",
-		imageRepo,
-	}
-
-	var stderr bytes.Buffer
-	listCmd := common.NewShellCmd(strings.Join(command, " "))
-	listCmd.ShowOutput = false
-	listCmd.Command.Stderr = &stderr
-	b, err := listCmd.Output()
-
 	if err != nil {
-		return []string{}, errors.New(strings.TrimSpace(stderr.String()))
+		return []string{}, fmt.Errorf("Unable to list images: %w", err)
+	}
+	if result.ExitCode != 0 {
+		return []string{}, fmt.Errorf("Unable to list images: %s", result.StderrContents())
 	}
 
-	output := strings.Split(strings.TrimSpace(string(b[:])), "\n")
+	output := strings.Split(result.StdoutContents(), "\n")
 	return output, nil
 }
 

plugins/common/docker.go

@@ -1,8 +1,6 @@
 package common
 
 import (
-	"bytes"
-	"errors"
 	"fmt"
 	"os"
 	"strings"
@@ -108,32 +106,20 @@ func CopyFromImage(appName string, image string, source string, destination stri
 	if err != nil {
 		return fmt.Errorf("Unable to create temporary container: %v", err)
 	}
+	defer ContainerRemove(containerID)
 
 	// docker cp exits with status 1 when run as non-root user when it tries to chown the file
 	// after successfully copying the file. Thus, we suppress stderr.
 	// ref: https://github.com/dotcloud/docker/issues/3986
-	containerCopyCmd := NewShellCmd(strings.Join([]string{
+	result, err := CallExecCommand(ExecCommandInput{
-		DockerBin(),
+		Command: DockerBin(),
-		"container",
+		Args:    []string{"container", "cp", fmt.Sprintf("%s:%s", containerID, source), tmpFile.Name()},
-		"cp",
+	})
-		fmt.Sprintf("%s:%s", containerID, source),
+	if err != nil {
-		tmpFile.Name(),
+		return fmt.Errorf("Unable to copy file %s from image: %w", source, err)
-	}, " "))
+	}
-	containerCopyCmd.ShowOutput = false
+	if result.ExitCode != 0 {
-	fileCopied := containerCopyCmd.Execute()
+		return fmt.Errorf("Unable to copy file %s from image: %v", source, result.StderrContents())
-
-	containerRemoveCmd := NewShellCmd(strings.Join([]string{
-		DockerBin(),
-		"container",
-		"rm",
-		"--force",
-		containerID,
-	}, " "))
-	containerRemoveCmd.ShowOutput = false
-	containerRemoveCmd.Execute()
-
-	if !fileCopied {
-		return fmt.Errorf("Unable to copy file %s from image", source)
 	}
 
 	fi, err := os.Stat(tmpFile.Name())
@@ -146,18 +132,13 @@ func CopyFromImage(appName string, image string, source string, destination stri
 	}
 
 	// workaround when owner is root. seems to only happen when running inside docker
-	dos2unixCmd := NewShellCmd(strings.Join([]string{
+	CallExecCommand(ExecCommandInput{
-		"dos2unix",
+		Command: "dos2unix",
-		"-l",
+		Args:    []string{"-l", "-n", tmpFile.Name(), destination},
-		"-n",
+	}) // nolint: errcheck
-		tmpFile.Name(),
-		destination,
-	}, " "))
-	dos2unixCmd.ShowOutput = false
-	dos2unixCmd.Execute()
 
 	// add trailing newline for certain places where file parsing depends on it
-	result, err := CallExecCommand(ExecCommandInput{
+	result, err = CallExecCommand(ExecCommandInput{
 		Command: "tail",
 		Args:    []string{"-c1", destination},
 	})
@@ -244,25 +225,26 @@ func DockerCleanup(appName string, forceCleanup bool) error {
 
 // DockerContainerCreate creates a new container and returns the container ID
 func DockerContainerCreate(image string, containerCreateArgs []string) (string, error) {
-	cmd := []string{
+	args := []string{
-		DockerBin(),
 		"container",
 		"create",
 	}
 
-	cmd = append(cmd, containerCreateArgs...)
+	args = append(args, containerCreateArgs...)
-	cmd = append(cmd, image)
+	args = append(args, image)
 
-	var stderr bytes.Buffer
+	result, err := CallExecCommand(ExecCommandInput{
-	containerCreateCmd := NewShellCmd(strings.Join(cmd, " "))
+		Command: DockerBin(),
-	containerCreateCmd.ShowOutput = false
+		Args:    args,
-	containerCreateCmd.Command.Stderr = &stderr
+	})
-	b, err := containerCreateCmd.Output()
 	if err != nil {
-		return "", errors.New(strings.TrimSpace(stderr.String()))
+		return "", fmt.Errorf("Unable to create container: %w", err)
+	}
+	if result.ExitCode != 0 {
+		return "", fmt.Errorf("Unable to create container: %s", result.StderrContents())
 	}
 
-	return strings.TrimSpace(string(b[:])), nil
+	return result.StdoutContents(), nil
 }
 
 // DockerInspect runs an inspect command with a given format against a container or image ID
@@ -359,21 +341,22 @@ func RemoveImages(imageIDs []string) error {
 		return nil
 	}
 
-	command := []string{
+	args := []string{
-		DockerBin(),
 		"image",
 		"rm",
 	}
 
-	command = append(command, imageIDs...)
+	args = append(args, imageIDs...)
 
-	var stderr bytes.Buffer
+	result, err := CallExecCommand(ExecCommandInput{
-	rmCmd := NewShellCmd(strings.Join(command, " "))
+		Command: DockerBin(),
-	rmCmd.ShowOutput = false
+		Args:    args,
-	rmCmd.Command.Stderr = &stderr
+	})
-	rmCmd.Execute()
+	if err != nil {
-	if _, err := rmCmd.Output(); err != nil {
+		return fmt.Errorf("Unable to remove images: %w", err)
-		return errors.New(strings.TrimSpace(stderr.String()))
+	}
+	if result.ExitCode != 0 {
+		return fmt.Errorf("Unable to remove images: %s", result.StderrContents())
 	}
 
 	return nil
@@ -381,15 +364,16 @@ func RemoveImages(imageIDs []string) error {
 
 // VerifyImage returns true if docker image exists in local repo
 func VerifyImage(image string) bool {
-	imageCmd := NewShellCmd(strings.Join([]string{DockerBin(), "image", "inspect", image}, " "))
+	result, err := CallExecCommand(ExecCommandInput{
-	imageCmd.ShowOutput = false
+		Command: DockerBin(),
-	return imageCmd.Execute()
+		Args:    []string{"image", "inspect", image},
+	})
+	return err == nil && result.ExitCode == 0
 }
 
 // DockerFilterContainers returns a slice of container IDs based on the passed in filters
 func DockerFilterContainers(filters []string) ([]string, error) {
-	command := []string{
+	args := []string{
-		DockerBin(),
 		"container",
 		"ls",
 		"--quiet",
@@ -397,27 +381,27 @@ func DockerFilterContainers(filters []string) ([]string, error) {
 	}
 
 	for _, filter := range filters {
-		command = append(command, "--filter", filter)
+		args = append(args, "--filter", filter)
 	}
 
-	var stderr bytes.Buffer
+	result, err := CallExecCommand(ExecCommandInput{
-	listCmd := NewShellCmd(strings.Join(command, " "))
+		Command: DockerBin(),
-	listCmd.ShowOutput = false
+		Args:    args,
-	listCmd.Command.Stderr = &stderr
+	})
-	b, err := listCmd.Output()
-
 	if err != nil {
-		return []string{}, errors.New(strings.TrimSpace(stderr.String()))
+		return []string{}, fmt.Errorf("Unable to filter containers: %w", err)
+	}
+	if result.ExitCode != 0 {
+		return []string{}, fmt.Errorf("Unable to filter containers: %s", result.StderrContents())
 	}
 
-	output := strings.Split(strings.TrimSpace(string(b[:])), "\n")
+	output := strings.Split(result.StdoutContents(), "\n")
 	return output, nil
 }
 
 // DockerFilterImages returns a slice of image IDs based on the passed in filters
 func DockerFilterImages(filters []string) ([]string, error) {
-	command := []string{
+	args := []string{
-		DockerBin(),
 		"image",
 		"ls",
 		"--quiet",
@@ -425,20 +409,21 @@ func DockerFilterImages(filters []string) ([]string, error) {
 	}
 
 	for _, filter := range filters {
-		command = append(command, "--filter", filter)
+		args = append(args, "--filter", filter)
 	}
 
-	var stderr bytes.Buffer
+	result, err := CallExecCommand(ExecCommandInput{
-	listCmd := NewShellCmd(strings.Join(command, " "))
+		Command: DockerBin(),
-	listCmd.ShowOutput = false
+		Args:    args,
-	listCmd.Command.Stderr = &stderr
+	})
-	b, err := listCmd.Output()
-
 	if err != nil {
-		return []string{}, errors.New(strings.TrimSpace(stderr.String()))
+		return []string{}, fmt.Errorf("Unable to filter images: %w", err)
+	}
+	if result.ExitCode != 0 {
+		return []string{}, fmt.Errorf("Unable to filter images: %s", result.StderrContents())
 	}
 
-	output := strings.Split(strings.TrimSpace(string(b[:])), "\n")
+	output := strings.Split(result.StdoutContents(), "\n")
 	return output, nil
 }
 
@@ -455,8 +440,7 @@ func listContainers(status string, appName string) ([]string, error) {
 }
 
 func pruneUnusedImages(appName string) {
-	command := []string{
+	args := []string{
-		DockerBin(),
 		"image",
 		"prune",
 		"--all",
@@ -465,26 +449,23 @@ func pruneUnusedImages(appName string) {
 		fmt.Sprintf("label=com.dokku.app-name=%v", appName),
 	}
 
-	var stderr bytes.Buffer
+	CallExecCommand(ExecCommandInput{
-	pruneCmd := NewShellCmd(strings.Join(command, " "))
+		Command: DockerBin(),
-	pruneCmd.ShowOutput = false
+		Args:    args,
-	pruneCmd.Command.Stderr = &stderr
+	}) // nolint: errcheck
-	pruneCmd.Execute()
 }
 
 // DockerRemoveContainers will call `docker container rm` on the specified containers
 func DockerRemoveContainers(containerIDs []string) {
-	command := []string{
+	args := []string{
-		DockerBin(),
 		"container",
 		"rm",
 	}
 
-	command = append(command, containerIDs...)
+	args = append(args, containerIDs...)
 
-	var stderr bytes.Buffer
+	CallExecCommand(ExecCommandInput{
-	rmCmd := NewShellCmd(strings.Join(command, " "))
+		Command: DockerBin(),
-	rmCmd.ShowOutput = false
+		Args:    args,
-	rmCmd.Command.Stderr = &stderr
+	}) // nolint: errcheck
-	rmCmd.Execute()
 }

plugins/common/io.go

@@ -38,15 +38,16 @@ func Copy(src, dst string) error {
 	}
 
 	// ensure file has the correct line endings
-	dos2unixCmd := NewShellCmd(strings.Join([]string{
+	result, err := CallExecCommand(ExecCommandInput{
-		"dos2unix",
+		Command: "dos2unix",
-		"-l",
+		Args:    []string{"-l", "-n", src, dst},
-		"-n",
+	})
-		src,
+	if err != nil {
-		dst,
+		return fmt.Errorf("Error running dos2unix: %s", err)
-	}, " "))
+	}
-	dos2unixCmd.ShowOutput = false
+	if result.ExitCode != 0 {
-	dos2unixCmd.Execute()
+		return fmt.Errorf("Error running dos2unix: %s", result.StderrContents())
+	}
 
 	// ensure file permissions are correct
 	b, err := os.ReadFile(dst)

plugins/network/functions.go

@@ -1,7 +1,6 @@
 package network
 
 import (
-	"bytes"
 	"errors"
 	"fmt"
 	"strings"
@@ -16,7 +15,6 @@ func attachAppToNetwork(containerID string, networkName string, appName string,
 	}
 
 	cmdParts := []string{
-		common.DockerBin(),
 		"network",
 		"connect",
 	}
@@ -43,14 +41,16 @@ func attachAppToNetwork(containerID string, networkName string, appName string,
 
 	cmdParts = append(cmdParts, networkName)
 	cmdParts = append(cmdParts, containerID)
-	attachCmd := common.NewShellCmd(strings.Join(cmdParts, " "))
+
-	var stderr bytes.Buffer
+	result, err := common.CallExecCommand(common.ExecCommandInput{
-	attachCmd.ShowOutput = false
+		Command: common.DockerBin(),
-	attachCmd.Command.Stderr = &stderr
+		Args:    cmdParts,
-	_, err := attachCmd.Output()
+	})
 	if err != nil {
-		err = errors.New(strings.TrimSpace(stderr.String()))
+		return fmt.Errorf("Unable to attach container to network: %w", err)
-		return fmt.Errorf("Unable to attach container to network: %v", err.Error())
+	}
+	if result.ExitCode != 0 {
+		return fmt.Errorf("Unable to attach container to network: %s", result.StderrContents())
 	}
 
 	return nil

plugins/network/subcommands.go

@@ -1,7 +1,6 @@
 package network
 
 import (
-	"bytes"
 	"errors"
 	"fmt"
 	"os"
@@ -13,22 +12,15 @@ import (
 // CommandCreate is an alias for "docker network create"
 func CommandCreate(networkName string) error {
 	common.LogInfo1Quiet(fmt.Sprintf("Creating network %v", networkName))
-	createCmd := common.NewShellCmd(strings.Join([]string{
+	result, err := common.CallExecCommand(common.ExecCommandInput{
-		common.DockerBin(),
+		Command: common.DockerBin(),
-		"network",
+		Args:    []string{"network", "create", "--attachable", "--label", fmt.Sprintf("com.dokku.network-name=%v", networkName), networkName},
-		"create",
+	})
-		"--attachable",
-		"--label",
-		fmt.Sprintf("com.dokku.network-name=%v", networkName),
-		networkName,
-	}, " "))
-	var stderr bytes.Buffer
-	createCmd.ShowOutput = false
-	createCmd.Command.Stderr = &stderr
-	_, err := createCmd.Output()
-
 	if err != nil {
-		err = errors.New(strings.TrimSpace(stderr.String()))
+		return fmt.Errorf("Unable to create network: %w", err)
+	}
+	if result.ExitCode != 0 {
+		return fmt.Errorf("Unable to create network: %s", result.StderrContents())
 	}
 
 	return err
@@ -47,22 +39,18 @@ func CommandDestroy(networkName string, forceDestroy bool) error {
 	}
 
 	common.LogInfo1Quiet(fmt.Sprintf("Destroying network %v", networkName))
-	destroyCmd := common.NewShellCmd(strings.Join([]string{
+	result, err := common.CallExecCommand(common.ExecCommandInput{
-		common.DockerBin(),
+		Command: common.DockerBin(),
-		"network",
+		Args:    []string{"network", "rm", networkName},
-		"rm",
+	})
-		networkName,
-	}, " "))
-	var stderr bytes.Buffer
-	destroyCmd.ShowOutput = false
-	destroyCmd.Command.Stderr = &stderr
-	_, err := destroyCmd.Output()
-
 	if err != nil {
-		err = errors.New(strings.TrimSpace(stderr.String()))
+		return fmt.Errorf("Unable to destroy network: %w", err)
+	}
+	if result.ExitCode != 0 {
+		return fmt.Errorf("Unable to destroy network: %s", result.StderrContents())
 	}
 
-	return err
+	return nil
 }
 
 // CommandExists checks if a network exists

plugins/ps/functions.go

@@ -1,7 +1,6 @@
 package ps
 
 import (
-	"bytes"
 	"errors"
 	"fmt"
 	"os"
@@ -24,26 +23,18 @@ func getProcfileCommand(procfilePath string, processType string, port int) (stri
 		return "", errors.New("No procfile found")
 	}
 
-	shellCmd := common.NewShellCmd(strings.Join([]string{
+	result, err := common.CallExecCommand(common.ExecCommandInput{
-		"procfile-util",
+		Command: "procfile-util",
-		"show",
+		Args:    []string{"show", "--procfile", procfilePath, "--process-type", processType, "--default-port", strconv.Itoa(port)},
-		"--procfile",
+	})
-		procfilePath,
-		"--process-type",
-		processType,
-		"--default-port",
-		strconv.Itoa(port),
-	}, " "))
-	var stderr bytes.Buffer
-	shellCmd.ShowOutput = false
-	shellCmd.Command.Stderr = &stderr
-	b, err := shellCmd.Output()
-
 	if err != nil {
-		return "", fmt.Errorf(strings.TrimSpace(stderr.String()))
+		return "", fmt.Errorf("Error running procfile-util: %s", err)
+	}
+	if result.ExitCode != 0 {
+		return "", fmt.Errorf("Error running procfile-util: %s", result.StderrContents())
 	}
 
-	return strings.TrimSpace(string(b[:])), nil
+	return result.StdoutContents(), nil
 }
 
 func getProcfilePath(appName string) string {
@@ -154,22 +145,18 @@ func parseProcessTuples(processTuples []string) (FormationSlice, error) {
 func processesInProcfile(procfilePath string) (map[string]bool, error) {
 	processes := map[string]bool{}
 
-	shellCmd := common.NewShellCmd(strings.Join([]string{
+	result, err := common.CallExecCommand(common.ExecCommandInput{
-		"procfile-util",
+		Command: "procfile-util",
-		"list",
+		Args:    []string{"list", "--procfile", procfilePath},
-		"--procfile",
+	})
-		procfilePath,
-	}, " "))
-	var stderr bytes.Buffer
-	shellCmd.ShowOutput = false
-	shellCmd.Command.Stderr = &stderr
-	b, err := shellCmd.Output()
-
 	if err != nil {
-		return processes, fmt.Errorf(strings.TrimSpace(stderr.String()))
+		return processes, fmt.Errorf("Error listing processes: %s", err)
+	}
+	if result.ExitCode != 0 {
+		return processes, fmt.Errorf("Error listing processes: %s", result.StderrContents())
 	}
 
-	for _, s := range strings.Split(strings.TrimSpace(string(b[:])), "\n") {
+	for _, s := range strings.Split(result.StdoutContents(), "\n") {
 		processes[s] = true
 	}
 

plugins/registry/subcommands.go

@@ -3,6 +3,7 @@ package registry
 import (
 	"bytes"
 	"errors"
+	"fmt"
 	"io"
 	"os"
 	"strings"
@@ -35,25 +36,23 @@ func CommandLogin(server string, username string, password string, passwordStdin
 		server = "docker.io"
 	}
 
-	command := []string{
-		common.DockerBin(),
-		"login",
-		"--username",
-		username,
-		"--password-stdin",
-		server,
-	}
-
 	buffer := bytes.Buffer{}
 	buffer.Write([]byte(password + "\n"))
 
-	loginCmd := common.NewShellCmd(strings.Join(command, " "))
+	result, err := common.CallExecCommand(common.ExecCommandInput{
-	loginCmd.Command.Stdin = &buffer
+		Command:      common.DockerBin(),
-	if !loginCmd.Execute() {
+		Args:         []string{"login", "--username", username, "--password-stdin", server},
-		return errors.New("Failed to log into registry")
+		Stdin:        &buffer,
+		StreamStderr: true,
+	})
+	if err != nil {
+		return fmt.Errorf("Unable to run docker login: %w", err)
+	}
+	if result.ExitCode != 0 {
+		return fmt.Errorf("Unable to run docker login: %s", result.StderrContents())
 	}
 
-	_, err := common.CallPlugnTrigger(common.PlugnTriggerInput{
+	_, err = common.CallPlugnTrigger(common.PlugnTriggerInput{
 		Trigger:     "post-registry-login",
 		Args:        []string{server, username},
 		StreamStdio: true,

plugins/repo/repo.go

@@ -2,8 +2,6 @@ package repo
 
 import (
 	"fmt"
-	"os"
-	"strings"
 
 	"github.com/dokku/dokku/plugins/common"
 )
@@ -33,18 +31,16 @@ func PurgeCache(appName string) error {
 	if len(containerIDs) > 0 {
 		common.DockerRemoveContainers(containerIDs)
 	}
-	purgeCacheCmd := common.NewShellCmd(strings.Join([]string{
+	result, err := common.CallExecCommand(common.ExecCommandInput{
-		common.DockerBin(),
+		Command:      common.DockerBin(),
-		"volume",
+		Args:         []string{"volume", "rm", "-f", fmt.Sprintf("cache-%s", appName)},
-		"rm", "-f", fmt.Sprintf("cache-%s", appName)}, " "))
+		StreamStderr: true,
-	purgeCacheCmd.ShowOutput = false
+	})
-	purgeCacheCmd.Command.Stderr = os.Stderr
+	if err != nil {
-	if !purgeCacheCmd.Execute() {
+		return fmt.Errorf("Unable to remove cache volume: %w", err)
-		exitCode := 1
+	}
-		if purgeCacheCmd.ExitError != nil {
+	if result.ExitCode != 0 {
-			exitCode = purgeCacheCmd.ExitError.ExitCode()
+		return &PurgeCacheFailed{result.ExitCode}
-		}
-		return &PurgeCacheFailed{exitCode}
 	}
 
 	return nil

plugins/repo/subcommands.go

@@ -1,6 +1,8 @@
 package repo
 
 import (
+	"fmt"
+
 	"github.com/dokku/dokku/plugins/common"
 )
 
@@ -14,9 +16,20 @@ func CommandGc(appName string) error {
 	cmdEnv := map[string]string{
 		"GIT_DIR": appRoot,
 	}
-	gitGcCmd := common.NewShellCmd("git gc --aggressive")
+
-	gitGcCmd.Env = cmdEnv
+	result, err := common.CallExecCommand(common.ExecCommandInput{
-	gitGcCmd.Execute()
+		Command:     "git",
+		Args:        []string{"gc", "--aggressive"},
+		Env:         cmdEnv,
+		StreamStdio: true,
+	})
+	if err != nil {
+		return fmt.Errorf("Unable to run git gc: %w", err)
+	}
+	if result.ExitCode != 0 {
+		return fmt.Errorf("Unable to run git gc: %s", result.StderrContents())
+	}
+
 	return nil
 }
 

plugins/scheduler-docker-local/functions.go

@@ -15,17 +15,28 @@ import (
 )
 
 func deleteCrontab() error {
-	command := common.NewShellCmd("sudo /usr/bin/crontab -l -u dokku")
+	result, err := common.CallExecCommand(common.ExecCommandInput{
-	command.ShowOutput = false
+		Command: "/usr/bin/crontab",
-	if !command.Execute() {
+		Args:    []string{"-l", "-u", "dokku"},
-		return nil
+		Sudo:    true,
+	})
+	if err != nil {
+		return fmt.Errorf("Unable to remove schedule file: %w", err)
+	}
+	if result.ExitCode != 0 {
+		return fmt.Errorf("Unable to remove schedule file: %s", result.StderrContents())
 	}
 
-	command = common.NewShellCmd("sudo /usr/bin/crontab -r -u dokku")
+	result, err = common.CallExecCommand(common.ExecCommandInput{
-	command.ShowOutput = false
+		Command: "/usr/bin/crontab",
-	out, err := command.CombinedOutput()
+		Args:    []string{"-r", "-u", "dokku"},
+		Sudo:    true,
+	})
 	if err != nil {
-		return fmt.Errorf("Unable to remove schedule file: %v", string(out))
+		return fmt.Errorf("Unable to remove schedule file: %w", err)
+	}
+	if result.ExitCode != 0 {
+		return fmt.Errorf("Unable to remove schedule file: %s", result.StderrContents())
 	}
 
 	common.LogInfo1("Removed")
@@ -139,11 +150,16 @@ func writeCronEntries() error {
 		return fmt.Errorf("Unable to template out schedule file: %v", err)
 	}
 
-	command := common.NewShellCmd(fmt.Sprintf("sudo /usr/bin/crontab -u dokku %s", tmpFile.Name()))
+	result, err := common.CallExecCommand(common.ExecCommandInput{
-	command.ShowOutput = false
+		Command: "/usr/bin/crontab",
-	out, err := command.CombinedOutput()
+		Args:    []string{"-u", "dokku", tmpFile.Name()},
+		Sudo:    true,
+	})
 	if err != nil {
-		return fmt.Errorf("Unable to update schedule file: %s", string(out))
+		return fmt.Errorf("Unable to update schedule file: %w", err)
+	}
+	if result.ExitCode != 0 {
+		return fmt.Errorf("Unable to update schedule file: %s", result.StderrContents())
 	}
 
 	common.LogInfo1("Updated schedule file")