Add listing of runners file system.

internal/runner/aws_runner.go

@@ -101,6 +101,13 @@ func (w *AWSFunctionWorkload) ExecuteInteractively(id string, _ io.ReadWriter, s
 	return exit, cancel, nil
 }
 
+// ListFileSystem is currently not supported with this aws serverless function.
+// This is because the function execution ends with the termination of the workload code.
+// So an on-demand file system listing after the termination is not possible. Also, we do not want to copy all files.
+func (w *AWSFunctionWorkload) ListFileSystem(_ string, _ bool, _ io.Writer, _ context.Context) error {
+	return dto.ErrNotSupported
+}
+
 // UpdateFileSystem copies Files into the executor.
 // Current limitation: No files can be deleted apart from the previously added files.
 // Future Work: Deduplication of the file systems, as the largest workload is likely to be used by additional

internal/runner/nomad_runner.go

@@ -118,6 +118,27 @@ func (r *NomadJob) ExecuteInteractively(
 	return exit, cancel, nil
 }
 
+func (r *NomadJob) ListFileSystem(path string, recursive bool, content io.Writer, ctx context.Context) error {
+	r.ResetTimeout()
+	command := "ls -l --time-style=+%s -1 --literal"
+	if recursive {
+		command += " --recursive"
+	}
+
+	ls2json := &nullio.Ls2JsonWriter{Target: content}
+	defer ls2json.Close()
+	retrieveCommand := (&dto.ExecutionRequest{Command: fmt.Sprintf("%s %s", command, path)}).FullCommand()
+	exitCode, err := r.api.ExecuteCommand(r.id, ctx, retrieveCommand, false, &nullio.Reader{}, ls2json, io.Discard)
+	if err != nil {
+		return fmt.Errorf("%w: nomad error during retrieve file headers: %v",
+			nomad.ErrorExecutorCommunicationFailed, err)
+	}
+	if exitCode != 0 {
+		return ErrFileNotFound
+	}
+	return nil
+}
+
 func (r *NomadJob) UpdateFileSystem(copyRequest *dto.UpdateFileSystemRequest) error {
 	r.ResetTimeout()
 

internal/runner/runner.go

@@ -44,11 +44,16 @@ type Runner interface {
 		stderr io.Writer,
 	) (exit <-chan ExitInfo, cancel context.CancelFunc, err error)
 
+	// ListFileSystem streams the listing of the file system of the requested directory into the Writer provided.
+	// The result is streamed via the io.Writer in order to not overload the memory with user input.
+	ListFileSystem(path string, recursive bool, result io.Writer, ctx context.Context) error
+
 	// UpdateFileSystem processes a dto.UpdateFileSystemRequest by first deleting each given dto.FilePath recursively
 	// and then copying each given dto.File to the runner.
 	UpdateFileSystem(request *dto.UpdateFileSystemRequest) error
 
 	// GetFileContent streams the file content at the requested path into the Writer provided at content.
+	// The result is streamed via the io.Writer in order to not overload the memory with user input.
 	GetFileContent(path string, content io.Writer, ctx context.Context) error
 
 	// Destroy destroys the Runner in Nomad.

internal/runner/runner_mock.go

@@ -120,6 +120,20 @@ func (_m *RunnerMock) ID() string {
 	return r0
 }
 
+// ListFileSystem provides a mock function with given fields: path, recursive, result, ctx
+func (_m *RunnerMock) ListFileSystem(path string, recursive bool, result io.Writer, ctx context.Context) error {
+	ret := _m.Called(path, recursive, result, ctx)
+
+	var r0 error
+	if rf, ok := ret.Get(0).(func(string, bool, io.Writer, context.Context) error); ok {
+		r0 = rf(path, recursive, result, ctx)
+	} else {
+		r0 = ret.Error(0)
+	}
+
+	return r0
+}
+
 // MappedPorts provides a mock function with given fields:
 func (_m *RunnerMock) MappedPorts() []*dto.MappedPort {
 	ret := _m.Called()