Use bare clones for git cloner (#421)

bufbuild · Aug 13, 2021 · 503f631 · 503f631
1 parent 99f94d0
commit 503f631
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Showing 4 changed files with 42 additions and 33 deletions.
diff --git a/go.mod b/go.mod
@@ -20,11 +20,11 @@ require (
 	go.opencensus.io v0.23.0
 	go.uber.org/multierr v1.7.0
 	go.uber.org/zap v1.19.0
-	golang.org/x/net v0.0.0-20210805182204-aaa1db679c0d // indirect
+	golang.org/x/net v0.0.0-20210813160813-60bc85c4be6d // indirect
 	golang.org/x/sys v0.0.0-20210809222454-d867a43fc93e // indirect
 	golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1
 	golang.org/x/text v0.3.7 // indirect
-	google.golang.org/genproto v0.0.0-20210811021853-ddbe55d93216 // indirect
+	google.golang.org/genproto v0.0.0-20210813162853-db860fec028c // indirect
 	google.golang.org/grpc v1.40.0-dev.0.20210708170655-30dfb4b933a5
 	google.golang.org/protobuf v1.27.1
 	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect

diff --git a/go.sum b/go.sum
@@ -361,8 +361,8 @@ golang.org/x/net v0.0.0-20210119194325-5f4716e94777/go.mod h1:m0MpNAwzfU5UDzcl9v
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20210316092652-d523dce5a7f4/go.mod h1:RBQZq4jEuRlivfhVLdyRGr576XBO4/greRjx4P4O3yc=
 golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
-golang.org/x/net v0.0.0-20210805182204-aaa1db679c0d h1:20cMwl2fHAzkJMEA+8J4JgqBQcQGzbisXo31MIeenXI=
-golang.org/x/net v0.0.0-20210805182204-aaa1db679c0d/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/net v0.0.0-20210813160813-60bc85c4be6d h1:LO7XpTYMwTqxjLcGWPijK3vRXg1aWdlNOVOHRq45d7c=
+golang.org/x/net v0.0.0-20210813160813-60bc85c4be6d/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
@@ -576,8 +576,8 @@ google.golang.org/genproto v0.0.0-20210310155132-4ce2db91004e/go.mod h1:FWY/as6D
 google.golang.org/genproto v0.0.0-20210319143718-93e7006c17a6/go.mod h1:FWY/as6DDZQgahTzZj3fqbO1CbirC29ZNUFHwi0/+no=
 google.golang.org/genproto v0.0.0-20210402141018-6c239bbf2bb1/go.mod h1:9lPAdzaEmUacj36I+k7YKbEc5CXzPIeORRgDAUOu28A=
 google.golang.org/genproto v0.0.0-20210602131652-f16073e35f0c/go.mod h1:UODoCrxHCcBojKKwX1terBiRUaqAsFqJiF615XL43r0=
-google.golang.org/genproto v0.0.0-20210811021853-ddbe55d93216 h1:qnrhhl4uoNFepTqE28u11llFcDH07Z6r/cQxpGR97A4=
-google.golang.org/genproto v0.0.0-20210811021853-ddbe55d93216/go.mod h1:cFeNkxwySK631ADgubI+/XFU/xp8FD5KIVV4rj8UC5w=
+google.golang.org/genproto v0.0.0-20210813162853-db860fec028c h1:iLQakcwWG3k/++1q/46apVb1sUQ3IqIdn9yUE6eh/xA=
+google.golang.org/genproto v0.0.0-20210813162853-db860fec028c/go.mod h1:cFeNkxwySK631ADgubI+/XFU/xp8FD5KIVV4rj8UC5w=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
 google.golang.org/grpc v1.20.1/go.mod h1:10oTOabMzJvdu6/UiuZezV6QK5dSlG84ov/aaiqXj38=
 google.golang.org/grpc v1.21.1/go.mod h1:oYelfM1adQP15Ek0mdvEgi9Df8B9CZIaU1084ijfRaM=

diff --git a/internal/pkg/git/cloner.go b/internal/pkg/git/cloner.go
@@ -32,11 +32,6 @@ import (
 	"go.uber.org/zap"
 )
 
-// bufCloneOrigin is the name for the remote. It helps distinguish the origin of
-// the repo we're cloning from the "origin" of our clone (which is the repo
-// being cloned).
-const bufCloneOrigin = "bufCloneOrigin"
-
 type cloner struct {
 	logger            *zap.Logger
 	storageosProvider storageos.Provider
@@ -83,30 +78,28 @@ func (c *cloner) CloneToBucket(
 
 	depthArg := strconv.Itoa(int(depth))
 
-	tmpDir, err := tmp.NewDir()
+	bareDir, err := tmp.NewDir()
 	if err != nil {
 		return err
 	}
 	defer func() {
-		retErr = multierr.Append(retErr, tmpDir.Close())
+		retErr = multierr.Append(retErr, bareDir.Close())
 	}()
-
-	buffer := bytes.NewBuffer(nil)
-	cmd := exec.CommandContext(ctx, "git", "init")
-	cmd.Dir = tmpDir.AbsPath()
-	cmd.Env = app.Environ(envContainer)
-	cmd.Stderr = buffer
-	if err := cmd.Run(); err != nil {
-		return newGitCommandError(err, buffer, tmpDir)
+	worktreeDir, err := tmp.NewDir()
+	if err != nil {
+		return err
 	}
+	defer func() {
+		retErr = multierr.Append(retErr, worktreeDir.Close())
+	}()
 
-	buffer.Reset()
-	cmd = exec.CommandContext(ctx, "git", "remote", "add", bufCloneOrigin, url)
-	cmd.Dir = tmpDir.AbsPath()
+	buffer := bytes.NewBuffer(nil)
+	cmd := exec.CommandContext(ctx, "git", "init", "--bare")
+	cmd.Dir = bareDir.AbsPath()
 	cmd.Env = app.Environ(envContainer)
 	cmd.Stderr = buffer
 	if err := cmd.Run(); err != nil {
-		return newGitCommandError(err, buffer, tmpDir)
+		return newGitCommandError(err, buffer, bareDir)
 	}
 
 	var gitConfigAuthArgs []string
@@ -122,9 +115,10 @@ func (c *cloner) CloneToBucket(
 	fetchRef, checkoutRefs := getRefspecsForName(options.Name)
 	fetchArgs := append(
 		gitConfigAuthArgs,
+		"--git-dir="+bareDir.AbsPath(),
 		"fetch",
 		"--depth", depthArg,
-		bufCloneOrigin,
+		url,
 		fetchRef,
 	)
 
@@ -137,32 +131,34 @@ func (c *cloner) CloneToBucket(
 
 	buffer.Reset()
 	cmd = exec.CommandContext(ctx, "git", fetchArgs...)
-	cmd.Dir = tmpDir.AbsPath()
 	cmd.Env = app.Environ(envContainer)
 	cmd.Stderr = buffer
 	if err := cmd.Run(); err != nil {
-		return newGitCommandError(err, buffer, tmpDir)
+		return newGitCommandError(err, buffer, bareDir)
 	}
 
 	for _, checkoutRef := range checkoutRefs {
 		buffer.Reset()
 		args := append(
 			gitConfigAuthArgs,
+			"--git-dir="+bareDir.AbsPath(),
+			"--work-tree="+worktreeDir.AbsPath(),
 			"checkout",
 			checkoutRef,
 		)
 		cmd = exec.CommandContext(ctx, "git", args...)
-		cmd.Dir = tmpDir.AbsPath()
 		cmd.Env = app.Environ(envContainer)
 		cmd.Stderr = buffer
 		if err := cmd.Run(); err != nil {
-			return newGitCommandError(err, buffer, tmpDir)
+			return newGitCommandError(err, buffer, worktreeDir)
 		}
 	}
 
 	if options.RecurseSubmodules {
 		submoduleArgs := append(
 			gitConfigAuthArgs,
+			"--git-dir="+bareDir.AbsPath(),
+			"--work-tree="+worktreeDir.AbsPath(),
 			"submodule",
 			"update",
 			"--init",
@@ -173,16 +169,15 @@ func (c *cloner) CloneToBucket(
 		buffer.Reset()
 		cmd = exec.CommandContext(ctx, "git", submoduleArgs...)
 		cmd.Env = app.Environ(envContainer)
-		cmd.Dir = tmpDir.AbsPath()
 		cmd.Stderr = buffer
 		if err := cmd.Run(); err != nil {
 			// Suppress printing of temp path
-			return fmt.Errorf("%v\n%v", err, strings.Replace(buffer.String(), tmpDir.AbsPath(), "", -1))
+			return fmt.Errorf("%v\n%v", err, strings.Replace(buffer.String(), worktreeDir.AbsPath(), "", -1))
 		}
 	}
 
 	// we do NOT want to read in symlinks
-	tmpReadWriteBucket, err := c.storageosProvider.NewReadWriteBucket(tmpDir.AbsPath())
+	tmpReadWriteBucket, err := c.storageosProvider.NewReadWriteBucket(worktreeDir.AbsPath())
 	if err != nil {
 		return err
 	}

diff --git a/internal/pkg/git/git_test.go b/internal/pkg/git/git_test.go
@@ -91,6 +91,17 @@ func TestGitCloner(t *testing.T) {
 		assert.True(t, storage.IsNotExist(err))
 	})
 
+	t.Run("branch_and_main_ref", func(t *testing.T) {
+		t.Parallel()
+		readBucket := readBucketForName(t, workDir, 2, NewRefNameWithBranch("HEAD~", "main"))
+
+		content, err := storage.ReadPath(context.Background(), readBucket, "test.proto")
+		require.NoError(t, err)
+		assert.Equal(t, "// commit 0", string(content))
+		_, err = readBucket.Stat(context.Background(), "nonexistent")
+		assert.True(t, storage.IsNotExist(err))
+	})
+
 	t.Run("branch_and_ref", func(t *testing.T) {
 		t.Parallel()
 		readBucket := readBucketForName(t, workDir, 2, NewRefNameWithBranch("local-branch~", "local-branch"))
@@ -173,6 +184,9 @@ func createGitDirs(t *testing.T) (string, string) {
 	runCommand(t, "git", "-C", originPath, "config", "user.email", "[email protected]")
 	runCommand(t, "git", "-C", originPath, "config", "user.name", "Buf go tests")
 	runCommand(t, "git", "-C", originPath, "checkout", "-b", "main")
+	require.NoError(t, os.WriteFile(filepath.Join(originPath, "test.proto"), []byte("// commit 0"), 0600))
+	runCommand(t, "git", "-C", originPath, "add", "test.proto")
+	runCommand(t, "git", "-C", originPath, "commit", "-m", "commit 0")
 	require.NoError(t, os.WriteFile(filepath.Join(originPath, "test.proto"), []byte("// commit 1"), 0600))
 	runCommand(t, "git", "-C", originPath, "add", "test.proto")
 	runCommand(t, "git", "-C", originPath, "commit", "-m", "commit 1")