added git FS; removed clone from generate pipeline (#1219)

git/api/fs.go

@@ -0,0 +1,240 @@
+// Copyright 2023 Harness, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package api
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"io/fs"
+	"time"
+
+	"github.com/harness/gitness/errors"
+	"github.com/harness/gitness/git/command"
+	"github.com/harness/gitness/git/sha"
+
+	"github.com/bmatcuk/doublestar/v4"
+)
+
+// FS represents a git filesystem.
+type FS struct {
+	ctx context.Context
+	rev string
+	dir string
+}
+
+// NewFS creates a new git filesystem.
+func NewFS(ctx context.Context, rev, dir string) *FS {
+	return &FS{
+		ctx: ctx,
+		rev: rev,
+		dir: dir,
+	}
+}
+
+func (f *FS) Open(path string) (fs.File, error) {
+	treeNode, err := GetTreeNode(f.ctx, f.dir, f.rev, path, true)
+	if err != nil {
+		return nil, err
+	}
+
+	if treeNode.IsDir() {
+		return nil, errors.InvalidArgument("can't open a directory")
+	}
+	if treeNode.IsLink() {
+		return nil, errors.InvalidArgument("can't open a link")
+	}
+	if treeNode.IsSubmodule() {
+		return nil, errors.InvalidArgument("can't open a submodule")
+	}
+
+	pipeRead, pipeWrite := io.Pipe()
+	ctx, cancelFn := context.WithCancel(f.ctx)
+	go func() {
+		var err error
+
+		defer func() {
+			// If running of the command below fails, make the pipe reader also fail with the same error.
+			_ = pipeWrite.CloseWithError(err)
+		}()
+
+		cmd := command.New("cat-file", command.WithFlag("-p"), command.WithArg(treeNode.SHA.String()))
+		err = cmd.Run(f.ctx, command.WithDir(f.dir), command.WithStdout(pipeWrite))
+	}()
+
+	pathFile := &file{
+		ctx:      ctx,
+		cancelFn: cancelFn,
+		path:     path,
+		blobSHA:  treeNode.SHA,
+		mode:     treeNode.Mode,
+		size:     treeNode.Size,
+		reader:   pipeRead,
+	}
+
+	return pathFile, nil
+}
+
+// ReadDir returns all entries for a directory.
+// It is part of the fs.ReadDirFS interface.
+func (f *FS) ReadDir(name string) ([]fs.DirEntry, error) {
+	treeNodes, err := ListTreeNodes(f.ctx, f.dir, f.rev, name, true)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read git directory: %w", err)
+	}
+
+	result := make([]fs.DirEntry, len(treeNodes))
+	for i, treeNode := range treeNodes {
+		result[i] = entry{treeNode}
+	}
+
+	return result, nil
+}
+
+// Glob returns all file names that match the pattern.
+// It is part of the fs.GlobFS interface.
+func (f *FS) Glob(pattern string) ([]string, error) {
+	return doublestar.Glob(f, pattern)
+}
+
+// Stat returns entry file info for a file path.
+// It is part of the fs.StatFS interface.
+func (f *FS) Stat(name string) (fs.FileInfo, error) {
+	treeInfo, err := GetTreeNode(f.ctx, f.dir, f.rev, name, true)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read git directory: %w", err)
+	}
+
+	return entry{*treeInfo}, nil
+}
+
+type file struct {
+	ctx      context.Context
+	cancelFn context.CancelFunc
+
+	path    string
+	blobSHA sha.SHA
+	mode    TreeNodeMode
+	size    int64
+
+	reader io.Reader
+}
+
+func (f *file) Stat() (fs.FileInfo, error) {
+	return f, nil
+}
+
+// Read bytes from the file.
+func (f *file) Read(bytes []byte) (int, error) {
+	return f.reader.Read(bytes)
+}
+
+// Close closes the file.
+func (f *file) Close() error {
+	f.cancelFn()
+	return nil
+}
+
+// Name returns the name of the file.
+// It is part of the fs.FileInfo interface.
+func (f *file) Name() string {
+	return f.path
+}
+
+// Size returns file size - the size of the git blob object.
+// It is part of the fs.FileInfo interface.
+func (f *file) Size() int64 {
+	return f.size
+}
+
+// Mode always returns 0 because a git blob is an ordinary file.
+// It is part of the fs.FileInfo interface.
+func (f *file) Mode() fs.FileMode {
+	return 0
+}
+
+// ModTime is unimplemented.
+// It is part of the fs.FileInfo interface.
+func (f *file) ModTime() time.Time {
+	// Git doesn't store file modification time directly.
+	// It's possible to find the last commit (and thus the commit time)
+	// that modified touched the file, but this is out of scope for this implementation.
+	return time.Time{}
+}
+
+// IsDir implementation for the file struct always returns false.
+// It is part of the fs.FileInfo interface.
+func (f *file) IsDir() bool {
+	return false
+}
+
+// Sys is unimplemented.
+// It is part of the fs.FileInfo interface.
+func (f *file) Sys() any {
+	return nil
+}
+
+type entry struct {
+	TreeNode
+}
+
+// Name returns name of a git tree entry.
+// It is part of the fs.DirEntry interface.
+func (e entry) Name() string {
+	return e.TreeNode.Name
+}
+
+// IsDir returns if a git tree entry is a directory.
+// It is part of the fs.FileInfo and fs.DirEntry interfaces.
+func (e entry) IsDir() bool {
+	return e.TreeNode.IsDir()
+}
+
+// Type returns the type of git tree entry.
+// It is part of the fs.DirEntry interface.
+func (e entry) Type() fs.FileMode {
+	if e.TreeNode.IsDir() {
+		return fs.ModeDir
+	}
+	return 0
+}
+
+// Info returns FileInfo for a git tree entry.
+// It is part of the fs.DirEntry interface.
+func (e entry) Info() (fs.FileInfo, error) {
+	return e, nil
+}
+
+// Size returns file size - the size of the git blob object.
+// It is part of the fs.FileInfo interface.
+func (e entry) Size() int64 {
+	return e.TreeNode.Size
+}
+
+// Mode always returns 0 because a git blob is an ordinary file.
+// It is part of the fs.FileInfo interface.
+func (e entry) Mode() fs.FileMode {
+	return 0
+}
+
+// ModTime is unimplemented. Git doesn't store file modification time directly.
+// It's possible to find the last commit (and thus the commit time)
+// that modified touched the file, but this is out of scope for this implementation.
+// It is part of the fs.FileInfo interface.
+func (e entry) ModTime() time.Time { return time.Time{} }
+
+// Sys is unimplemented.
+// It is part of the fs.FileInfo interface.
+func (e entry) Sys() any { return nil }

git/api/match_files.go

@@ -35,7 +35,7 @@ func (g *Git) MatchFiles(
 	pattern string,
 	maxSize int,
 ) ([]FileContent, error) {
-	nodes, err := lsDirectory(ctx, repoPath, rev, treePath)
+	nodes, err := lsDirectory(ctx, repoPath, rev, treePath, false)
 	if err != nil {
 		return nil, fmt.Errorf("failed to list files in match files: %w", err)
 	}

git/api/tree.go

@@ -44,6 +44,7 @@ type TreeNode struct {
 	SHA      sha.SHA
 	Name     string
 	Path     string
+	Size     int64
 }
 
 func (n *TreeNode) IsExecutable() bool {
@@ -58,6 +59,10 @@ func (n *TreeNode) IsLink() bool {
 	return n.Mode == TreeNodeModeSymlink
 }
 
+func (n *TreeNode) IsSubmodule() bool {
+	return n.Mode == TreeNodeModeCommit
+}
+
 // TreeNodeType specifies the different types of nodes in a git tree.
 // IMPORTANT: has to be consistent with rpc.TreeNodeType (proto).
 type TreeNodeType int
@@ -122,13 +127,14 @@ func parseTreeNodeMode(s string) (TreeNodeType, TreeNodeMode, error) {
 // regexpLsTreeColumns is a regular expression that is used to parse a single line
 // of a "git ls-tree" output (which uses the NULL character as the line break).
 // The single line mode must be used because output might contain the EOL and other control characters.
-var regexpLsTreeColumns = regexp.MustCompile(`(?s)^(\d{6})\s+(\w+)\s+(\w+)\t(.+)`)
+var regexpLsTreeColumns = regexp.MustCompile(`(?s)^(\d{6})\s+(\w+)\s+(\w+)(?:\s+(\d+|-))?\t(.+)`)
 
 func lsTree(
 	ctx context.Context,
 	repoPath string,
 	rev string,
 	treePath string,
+	fetchSizes bool,
 ) ([]TreeNode, error) {
 	if repoPath == "" {
 		return nil, ErrRepositoryPathEmpty
@@ -138,6 +144,10 @@ func lsTree(
 		command.WithArg(rev),
 		command.WithArg(treePath),
 	)
+	if fetchSizes {
+		cmd.Add(command.WithFlag("-l"))
+	}
+
 	output := &bytes.Buffer{}
 	err := cmd.Run(ctx,
 		command.WithDir(repoPath),
@@ -183,7 +193,19 @@ func lsTree(
 		}
 
 		nodeSha := sha.Must(columns[3])
-		nodePath := columns[4]
+
+		var size int64
+		if columns[4] != "" && columns[4] != "-" {
+			size, err = strconv.ParseInt(columns[4], 10, 64)
+			if err != nil {
+				log.Ctx(ctx).Error().
+					Str("line", line).
+					Msg("failed to parse file size")
+				return nil, fmt.Errorf("failed to parse file size in the git directory listing: %q", line)
+			}
+		}
+
+		nodePath := columns[5]
 		nodeName := path.Base(nodePath)
 
 		list = append(list, TreeNode{
@@ -192,6 +214,7 @@ func lsTree(
 			SHA:      nodeSha,
 			Name:     nodeName,
 			Path:     nodePath,
+			Size:     size,
 		})
 	}
 
@@ -204,6 +227,7 @@ func lsDirectory(
 	repoPath string,
 	rev string,
 	treePath string,
+	fetchSizes bool,
 ) ([]TreeNode, error) {
 	treePath = path.Clean(treePath)
 	if treePath == "" {
@@ -212,7 +236,7 @@ func lsDirectory(
 		treePath += "/"
 	}
 
-	return lsTree(ctx, repoPath, rev, treePath)
+	return lsTree(ctx, repoPath, rev, treePath, fetchSizes)
 }
 
 // lsFile returns one tree node entry.
@@ -221,10 +245,11 @@ func lsFile(
 	repoPath string,
 	rev string,
 	treePath string,
+	fetchSize bool,
 ) (TreeNode, error) {
 	treePath = cleanTreePath(treePath)
 
-	list, err := lsTree(ctx, repoPath, rev, treePath)
+	list, err := lsTree(ctx, repoPath, rev, treePath, fetchSize)
 	if err != nil {
 		return TreeNode{}, fmt.Errorf("failed to ls file: %w", err)
 	}
@@ -237,18 +262,18 @@ func lsFile(
 
 // GetTreeNode returns the tree node at the given path as found for the provided reference.
 func (g *Git) GetTreeNode(ctx context.Context, repoPath, rev, treePath string) (*TreeNode, error) {
-	return GetTreeNode(ctx, repoPath, rev, treePath)
+	return GetTreeNode(ctx, repoPath, rev, treePath, false)
 }
 
 // GetTreeNode returns the tree node at the given path as found for the provided reference.
-func GetTreeNode(ctx context.Context, repoPath, rev, treePath string) (*TreeNode, error) {
+func GetTreeNode(ctx context.Context, repoPath, rev, treePath string, fetchSize bool) (*TreeNode, error) {
 	if repoPath == "" {
 		return nil, ErrRepositoryPathEmpty
 	}
 
 	// anything that's not the root path is a simple call
 	if treePath != "" {
-		treeNode, err := lsFile(ctx, repoPath, rev, treePath)
+		treeNode, err := lsFile(ctx, repoPath, rev, treePath, fetchSize)
 		if err != nil {
 			return nil, fmt.Errorf("failed to get tree node: %w", err)
 		}
@@ -285,7 +310,12 @@ func GetTreeNode(ctx context.Context, repoPath, rev, treePath string) (*TreeNode
 
 // ListTreeNodes lists the child nodes of a tree reachable from ref via the specified path.
 func (g *Git) ListTreeNodes(ctx context.Context, repoPath, rev, treePath string) ([]TreeNode, error) {
-	list, err := lsDirectory(ctx, repoPath, rev, treePath)
+	return ListTreeNodes(ctx, repoPath, rev, treePath, false)
+}
+
+// ListTreeNodes lists the child nodes of a tree reachable from ref via the specified path.
+func ListTreeNodes(ctx context.Context, repoPath, rev, treePath string, fetchSizes bool) ([]TreeNode, error) {
+	list, err := lsDirectory(ctx, repoPath, rev, treePath, fetchSizes)
 	if err != nil {
 		return nil, fmt.Errorf("failed to list tree nodes: %w", err)
 	}

git/pipeline.go

@@ -17,13 +17,10 @@ package git
 import (
 	"context"
 	"fmt"
-	"os"
 
 	"github.com/harness/gitness/git/api"
 
 	"github.com/drone/go-generate/builder"
-	"github.com/drone/go-generate/chroot"
-	"github.com/rs/zerolog/log"
 )
 
 type GeneratePipelineParams struct {
@@ -42,34 +39,20 @@ func (s *Service) GeneratePipeline(ctx context.Context,
 	}
 	repoPath := getFullPathForRepo(s.reposRoot, params.RepoUID)
 
-	tempDir, err := os.MkdirTemp(s.tmpDir, "*-"+params.RepoUID)
+	sha, err := s.git.ResolveRev(ctx, repoPath, "HEAD")
 	if err != nil {
-		return GeneratePipelinesOutput{}, fmt.Errorf("error creating temp dir for repo %s: %w", params.RepoUID, err)
-	}
-	defer func(path string) {
-		// when repo is successfully created remove temp dir
-		errRm := os.RemoveAll(path)
-		if errRm != nil {
-			log.Err(errRm).Msg("failed to cleanup temporary dir.")
-		}
-	}(tempDir)
-
-	// Clone repository to temp dir
-	if err = s.git.Clone(ctx, repoPath, tempDir, api.CloneRepoOptions{Depth: 1}); err != nil {
-		return GeneratePipelinesOutput{}, fmt.Errorf("failed to clone repo: %w", err)
+		return GeneratePipelinesOutput{}, fmt.Errorf("failed to resolve HEAD revision: %w", err)
 	}
 
-	// create a chroot virtual filesystem that we
-	// pass to the builder for isolation purposes.
-	chroot, err := chroot.New(tempDir)
-	if err != nil {
-		return GeneratePipelinesOutput{}, fmt.Errorf("failed to set the temp directory as active directory: %w", err)
-	}
+	ctxFS, cancelFn := context.WithCancel(ctx)
+	defer cancelFn()
+
+	gitFS := api.NewFS(ctxFS, sha.String(), repoPath)
 
 	// builds the pipeline configuration based on
 	// the contents of the virtual filesystem.
 	builder := builder.New()
-	out, err := builder.Build(chroot)
+	out, err := builder.Build(gitFS)
 	if err != nil {
 		return GeneratePipelinesOutput{}, fmt.Errorf("failed to build pipeline: %w", err)
 	}

git/sha/sha.go

@@ -91,7 +91,8 @@ func (s *SHA) UnmarshalJSON(content []byte) error {
 	if err != nil {
 		return err
 	}
-	sha, err := New(str)
+
+	sha, err := NewOrEmpty(str)
 	if err != nil {
 		return err
 	}

git/sha/sha_test.go

@@ -76,10 +76,10 @@ func TestSHA_UnmarshalJSON(t *testing.T) {
 			wantErr: false,
 		},
 		{
-			name:     "empty content return error",
+			name:     "empty content returns empty",
 			input:    []byte("\"\""),
 			expected: SHA{},
-			wantErr:  true,
+			wantErr:  false,
 		},
 	}
 	for _, tt := range tests {

git/sharedrepo/sharedrepo.go

@@ -581,7 +581,7 @@ func (r *SharedRepo) getFileEntry(
 	objectSHA sha.SHA,
 	path string,
 ) (*api.TreeNode, error) {
-	entry, err := api.GetTreeNode(ctx, r.repoPath, treeishSHA.String(), path)
+	entry, err := api.GetTreeNode(ctx, r.repoPath, treeishSHA.String(), path, false)
 	if errors.IsNotFound(err) {
 		return nil, errors.NotFound("path %s not found", path)
 	}
@@ -615,7 +615,7 @@ func (r *SharedRepo) checkPathAvailability(
 	for index, part := range parts {
 		subTreePath = path.Join(subTreePath, part)
 
-		entry, err := api.GetTreeNode(ctx, r.repoPath, treeishSHA.String(), subTreePath)
+		entry, err := api.GetTreeNode(ctx, r.repoPath, treeishSHA.String(), subTreePath, false)
 		if err != nil {
 			if errors.IsNotFound(err) {
 				// Means there is no item with that name, so we're good