Add a new config parameter to automatically attach to container using specific shells

pkg/config/app_config.go

@@ -216,6 +216,9 @@ type CommandTemplatesConfig struct {
 
 	// ServiceTop is the command for viewing the processes under a given service
 	ServiceTop string `yaml:"serviceTop,omitempty"`
+
+	// List of shells that, in given order, will be tried when attaching to a container.
+	PreferredExecShells []string `yaml:"preferedExecShell,omitempty"`
 }
 
 // OSConfig contains config on the level of the os
@@ -398,6 +401,7 @@ func GetDefaultConfig() UserConfig {
 			DockerComposeConfig:      "{{ .DockerCompose }} config",
 			CheckDockerComposeConfig: "{{ .DockerCompose }} config --quiet",
 			ServiceTop:               "{{ .DockerCompose }} top {{ .Service.Name }}",
+			PreferredExecShells:      []string{},
 		},
 		CustomCommands: CustomCommands{
 			Containers: []CustomCommand{},

pkg/gui/containers_panel.go

@@ -449,11 +449,32 @@ func (gui *Gui) containerExecShell(container *commands.Container) error {
 	commandObject := gui.DockerCommand.NewCommandObject(commands.CommandObject{
 		Container: container,
 	})
+	var command string
+	shell := ""
+
+	preferredExecShells := gui.Config.UserConfig.CommandTemplates.PreferredExecShells
+	if len(preferredExecShells) > 0 {
+		for _, preferredExecShell := range preferredExecShells {
+			command := utils.ApplyTemplate(fmt.Sprintf("docker exec {{ .Container.ID }} which %s", preferredExecShell), commandObject)
+
+			err := gui.runCommandSilently(gui.OSCommand.ExecutableFromString(command))
+			if err == nil {
+				shell = preferredExecShell
+				break
+			}
+		}
+	}
+
+	// TODO: Use SDK
+	// Use default implementation in case we cannot fulfill user's preference
+	if shell == "" {
+		command = utils.ApplyTemplate("docker exec -it {{ .Container.ID }} /bin/sh -c 'eval $(grep ^$(id -un): /etc/passwd | cut -d : -f 7-)'", commandObject)
+	} else {
+		command = utils.ApplyTemplate(fmt.Sprintf("docker exec -it {{ .Container.ID }} %s", shell), commandObject)
+	}
 
-	// TODO: use SDK
-	resolvedCommand := utils.ApplyTemplate("docker exec -it {{ .Container.ID }} /bin/sh -c 'eval $(grep ^$(id -un): /etc/passwd | cut -d : -f 7-)'", commandObject)
+	cmd := gui.OSCommand.ExecutableFromString(command)
 	// attach and return the subprocess error
-	cmd := gui.OSCommand.ExecutableFromString(resolvedCommand)
 	return gui.runSubprocess(cmd)
 }
 

pkg/gui/subprocess.go

@@ -26,18 +26,34 @@ func (gui *Gui) runSubprocessWithMessage(cmd *exec.Cmd, msg string) error {
 
 	gui.PauseBackgroundThreads = true
 
-	gui.runCommand(cmd, msg)
+	err := gui.runCommand(cmd, msg)
 
 	if err := gui.g.Resume(); err != nil {
 		return gui.createErrorPanel(err.Error())
 	}
 
 	gui.PauseBackgroundThreads = false
 
-	return nil
+	return err
 }
 
-func (gui *Gui) runCommand(cmd *exec.Cmd, msg string) {
+func (gui *Gui) runCommandSilently(cmd *exec.Cmd) error {
+	stop := make(chan os.Signal, 1)
+	defer signal.Stop(stop)
+
+	go func() {
+		signal.Notify(stop, os.Interrupt)
+		<-stop
+
+		if err := gui.OSCommand.Kill(cmd); err != nil {
+			gui.Log.Error(err)
+		}
+	}()
+
+	return cmd.Run()
+}
+
+func (gui *Gui) runCommand(cmd *exec.Cmd, msg string) error {
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stdout
 	cmd.Stdin = os.Stdin
@@ -58,9 +74,9 @@ func (gui *Gui) runCommand(cmd *exec.Cmd, msg string) {
 	if msg != "" {
 		fmt.Fprintf(os.Stdout, "\n%s\n\n", utils.ColoredString(msg, color.FgGreen))
 	}
-	if err := cmd.Run(); err != nil {
-		// not handling the error explicitly because usually we're going to see it
-		// in the output anyway
+	err := cmd.Run()
+
+	if err != nil {
 		gui.Log.Error(err)
 	}
 
@@ -69,4 +85,6 @@ func (gui *Gui) runCommand(cmd *exec.Cmd, msg string) {
 	cmd.Stderr = io.Discard
 
 	gui.promptToReturn()
+
+	return err
 }