feat(git-clone): add support for submodules

pkg/controller/git/mock_repo.go

@@ -30,6 +30,7 @@ type MockRepo struct {
 	RemoteBranchExistsFn      func(branch string) (bool, error)
 	ResetHardFn               func() error
 	URLFn                     func() string
+	UpdateSubmodulesFn        func() error
 }
 
 func (m *MockRepo) AddAll() error {
@@ -146,3 +147,7 @@ func (m *MockRepo) ResetHard() error {
 func (m *MockRepo) URL() string {
 	return m.URLFn()
 }
+
+func (m *MockRepo) UpdateSubmodules() error {
+	return m.UpdateSubmodulesFn()
+}

pkg/controller/git/work_tree.go

@@ -87,6 +87,8 @@ type WorkTree interface {
 	ResetHard() error
 	// URL returns the remote URL of the repository.
 	URL() string
+	// UpdateSubmodules updates the submodules in the working tree.
+	UpdateSubmodules() error
 }
 
 // workTree is an implementation of the WorkTree interface for interacting with
@@ -634,3 +636,10 @@ func (w *workTree) ResetHard() error {
 	}
 	return nil
 }
+
+func (w *workTree) UpdateSubmodules() error {
+	if _, err := libExec.Exec(w.buildGitCommand("submodule", "update", "--init", "--recursive")); err != nil {
+		return fmt.Errorf("error updating submodules: %w", err)
+	}
+	return nil
+}

pkg/promotion/runner/builtin/git_cloner.go

@@ -187,6 +187,13 @@ func (g *gitCloner) run(
 					checkout.Path, cfg.RepoURL, err,
 				)
 		}
+		if cfg.RecurseSubmodules {
+			err = worktree.UpdateSubmodules()
+			if err != nil {
+				return promotion.StepResult{Status: kargoapi.PromotionStepStatusErrored},
+					fmt.Errorf("error updating submodules for worktree at %s: %w", path, err)
+			}
+		}
 		key := checkout.Path
 		if checkout.As != "" {
 			key = checkout.As

pkg/promotion/runner/builtin/git_cloner_test.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net/http/httptest"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"testing"
 
@@ -393,3 +394,75 @@ func Test_gitCloner_run(t *testing.T) {
 		res.Output["commits"],
 	)
 }
+
+func Test_gitCloner_run_with_submodules(t *testing.T) {
+	// Set up a test Git server in-process
+	service := gitkit.New(
+		gitkit.Config{
+			Dir:        t.TempDir(),
+			AutoCreate: true,
+		},
+	)
+	require.NoError(t, service.Setup())
+	server := httptest.NewServer(service)
+	defer server.Close()
+
+	// Create submodule remote repo and push a file
+	subRepoURL := fmt.Sprintf("%s/sub.git", server.URL)
+	subRepo, err := git.Clone(subRepoURL, nil, nil)
+	require.NoError(t, err)
+	defer subRepo.Close()
+	err = os.WriteFile(filepath.Join(subRepo.Dir(), "sub.txt"), []byte("sub"), 0600)
+	require.NoError(t, err)
+	err = subRepo.AddAllAndCommit("Initial commit sub", nil)
+	require.NoError(t, err)
+	err = subRepo.Push(nil)
+	require.NoError(t, err)
+
+	// Create main repo and add the submodule
+	mainRepoURL := fmt.Sprintf("%s/main.git", server.URL)
+	mainRepo, err := git.Clone(mainRepoURL, nil, nil)
+	require.NoError(t, err)
+	defer mainRepo.Close()
+
+	// Use git submodule add to create proper submodule metadata
+	cmd := exec.Command("git", "submodule", "add", subRepoURL, "sub")
+	cmd.Dir = mainRepo.Dir()
+	out, err := cmd.CombinedOutput()
+	require.NoErrorf(t, err, "git submodule add failed: %s", string(out))
+
+	// Commit and push the submodule addition
+	err = mainRepo.AddAllAndCommit("Add submodule", nil)
+	require.NoError(t, err)
+	err = mainRepo.Push(nil)
+	require.NoError(t, err)
+
+	mainCommitID, err := mainRepo.LastCommitID()
+	require.NoError(t, err)
+
+	// Run git-cloner with recurseSubmodules = true
+	r := newGitCloner(promotion.StepRunnerCapabilities{
+		CredsDB: &credentials.FakeDB{},
+	})
+	runner, ok := r.(*gitCloner)
+	require.True(t, ok)
+
+	stepCtx := &promotion.StepContext{
+		WorkDir: t.TempDir(),
+	}
+
+	res, err := runner.run(
+		context.Background(),
+		stepCtx,
+		builtin.GitCloneConfig{
+			RepoURL:           mainRepoURL,
+			Checkout:          []builtin.Checkout{{Commit: mainCommitID, Path: "src"}},
+			RecurseSubmodules: true,
+		},
+	)
+	require.NoError(t, err)
+	require.Equal(t, kargoapi.PromotionStepStatusSucceeded, res.Status)
+
+	// Assert submodule file was populated inside worktree
+	require.FileExists(t, filepath.Join(stepCtx.WorkDir, "src", "sub", "sub.txt"))
+}

pkg/promotion/runner/builtin/schemas/git-clone-config.json

@@ -9,6 +9,10 @@
       "type": "boolean",
       "description": "Indicates whether to skip TLS verification when cloning the repository. Default is false."
     },
+    "recurseSubmodules": {
+      "type": "boolean",
+      "description": "Indicates whether to recursively clone submodules. Default is false. Note that any provided credentials must also be valid for the submodules."
+    },
     "repoURL": {
       "type": "string",
       "description": "The URL of a remote Git repository to clone. Required.",

ui/src/gen/directives/git-clone-config.json

@@ -8,6 +8,10 @@
    "type": "boolean",
    "description": "Indicates whether to skip TLS verification when cloning the repository. Default is false."
   },
+  "recurseSubmodules": {
+   "type": "boolean",
+   "description": "Indicates whether to recursively clone submodules. Default is false. Note that any provided credentials must also be valid for the submodules."
+  },
   "repoURL": {
    "type": "string",
    "description": "The URL of a remote Git repository to clone. Required.",