Allow specifying user shell at toolbox creation

When creating a toolbox the user shell can be specified and this shell will be
used when entering the toolbox.

Signed-off-by: Yann Soubeyrand <[email protected]>

src/cmd/create.go

@@ -44,6 +44,7 @@ var (
 		container string
 		image     string
 		release   string
+		shell     string
 	}
 
 	createToolboxShMounts = []struct {
@@ -82,6 +83,12 @@ func init() {
 		"",
 		"Create a toolbox container for a different operating system release than the host.")
 
+	flags.StringVarP(&createFlags.shell,
+		"shell",
+		"s",
+		"",
+		"Specify the shell to use in the toolbox.")
+
 	createCmd.SetHelpFunc(createHelp)
 	rootCmd.AddCommand(createCmd)
 }
@@ -139,14 +146,23 @@ func create(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
-	if err := createContainer(container, image, release, true); err != nil {
+	var userShell string
+	if createFlags.shell != "" {
+		userShell = createFlags.shell
+		if !filepath.IsAbs(userShell) {
+			return fmt.Errorf("Invalid shell '%s': must be an absolute path", userShell)
+		}
+		userShell = filepath.Clean(userShell)
+	}
+
+	if err := createContainer(container, image, release, userShell, true); err != nil {
 		return err
 	}
 
 	return nil
 }
 
-func createContainer(container, image, release string, showCommandToEnter bool) error {
+func createContainer(container, image, release string, userShell string, showCommandToEnter bool) error {
 	if container == "" {
 		panic("container not specified")
 	}
@@ -311,9 +327,11 @@ func createContainer(container, image, release string, showCommandToEnter bool)
 
 	logLevelString := podman.LogLevel.String()
 
-	userShell := os.Getenv("SHELL")
 	if userShell == "" {
-		return errors.New("failed to get the current user's default shell")
+		userShell = os.Getenv("SHELL")
+		if userShell == "" {
+			return errors.New("failed to get the current user's default shell")
+		}
 	}
 
 	entryPoint := []string{

src/cmd/enter.go

@@ -114,13 +114,6 @@ func enter(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
-	userShell := os.Getenv("SHELL")
-	if userShell == "" {
-		return errors.New("failed to get the current user's default shell")
-	}
-
-	command := []string{userShell, "-l"}
-
 	hostID, err := utils.GetHostID()
 	if err != nil {
 		return errors.New("failed to get the host ID")
@@ -137,18 +130,13 @@ func enter(cmd *cobra.Command, args []string) error {
 		emitEscapeSequence = true
 	}
 
-	if err := runCommand(container,
+	return runCommand(container,
 		!nonDefaultContainer,
 		image,
 		release,
-		command,
+		nil,
 		emitEscapeSequence,
-		true,
-		false); err != nil {
-		return err
-	}
-
-	return nil
+		false)
 }
 
 func enterHelp(cmd *cobra.Command, args []string) {

src/cmd/run.go

@@ -120,25 +120,20 @@ func run(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
-	if err := runCommand(container,
+	return runCommand(container,
 		!nonDefaultContainer,
 		image,
 		release,
 		command,
 		false,
-		false,
-		true); err != nil {
-		return err
-	}
-
-	return nil
+		true)
 }
 
 func runCommand(container string,
 	defaultContainer bool,
 	image, release string,
 	command []string,
-	emitEscapeSequence, fallbackToBash, pedantic bool) error {
+	emitEscapeSequence, pedantic bool) error {
 	if !pedantic {
 		if image == "" {
 			panic("image not specified")
@@ -188,7 +183,7 @@ func runCommand(container string,
 				return nil
 			}
 
-			if err := createContainer(container, image, release, false); err != nil {
+			if err := createContainer(container, image, release, "", false); err != nil {
 				return err
 			}
 		} else if containersCount == 1 && defaultContainer {
@@ -255,16 +250,15 @@ func runCommand(container string,
 
 	logrus.Debugf("Container %s is initialized", container)
 
-	if _, err := isCommandPresent(container, command[0]); err != nil {
-		if fallbackToBash {
-			logrus.Debugf("command %s not found in container %s; using /bin/bash instead",
-				command[0],
-				container)
+	commandLauncher := "export SHELL=\"$(getent passwd \"$(whoami)\" | cut -d : -f 7)\"; "
 
-			command = []string{"/bin/bash"}
-		} else {
+	if command != nil {
+		if _, err := isCommandPresent(container, command[0]); err != nil {
 			return fmt.Errorf("command %s not found in container %s", command[0], container)
 		}
+		commandLauncher += "exec \"$@\""
+	} else {
+		commandLauncher += "exec -l \"$SHELL\""
 	}
 
 	envOptions := utils.GetEnvOptionsForPreservedVariables()
@@ -283,10 +277,14 @@ func runCommand(container string,
 
 	execArgs = append(execArgs, []string{
 		container,
-		"capsh", "--caps=", "--", "-c", "exec \"$@\"", "/bin/sh",
+		"capsh", "--caps=", "--", "-c", commandLauncher, "toolbox",
 	}...)
 
-	execArgs = append(execArgs, command...)
+	if command != nil {
+		execArgs = append(execArgs, command...)
+	} else {
+		command = []string{"\"$SHELL\""}
+	}
 
 	if emitEscapeSequence {
 		fmt.Printf("\033]777;container;push;%s;toolbox\033\\", container)
@@ -319,11 +317,7 @@ func runCommand(container string,
 		err = nil
 	}
 
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return err
 }
 
 func runHelp(cmd *cobra.Command, args []string) {

src/pkg/utils/utils.go

@@ -57,7 +57,6 @@ var (
 		"DESKTOP_SESSION",
 		"DISPLAY",
 		"LANG",
-		"SHELL",
 		"SSH_AUTH_SOCK",
 		"TERM",
 		"TOOLBOX_PATH",