perf: speed up action downloads (#1209)

An action pinned to a full commit hash cloned the whole repository, and a cached one hit the network on every run. Now only the pinned commit is fetched at depth 1, a cached commit is reused with no network at all, and the action's `.git` directory no longer ships into the job container, matching GitHub.

```
repo                  cold ms         warm ms       cache KiB
actions/checkout      5807 → 787    1064 → 12    11492 → 2349
actions/setup-node   15257 → 1013   1365 → 21    64303 → 9924
actions/cache        18782 → 760    1589 → 16    60890 → 12507
actions/setup-go      5513 → 764     589 → 20    16600 → 9104
docker/login-action  25809 → 1225   1288 → 10    81709 → 12503
```

Reviewed-on: https://gitea.com/gitea/runner/pulls/1209
Reviewed-by: bircni <bircni@icloud.com>
Co-authored-by: silverwind <me@silverwind.io>

act/container/container_types.go

@@ -90,7 +90,7 @@ type Info struct {
 type Container interface {
 	Create(capAdd, capDrop []string) common.Executor
 	Copy(destPath string, files ...*FileEntry) common.Executor
-	CopyDir(destPath, srcPath string, useGitIgnore bool) common.Executor
+	CopyDir(destPath, srcPath string, useGitIgnore, skipGitDir bool) common.Executor
 	GetContainerArchive(ctx context.Context, srcPath string) (io.ReadCloser, error)
 	Inspect(ctx context.Context) (*Info, error)
 	DumpLogs(ctx context.Context) error

act/container/docker_run.go

@@ -138,12 +138,12 @@ func (cr *containerReference) Copy(destPath string, files ...*FileEntry) common.
 	).IfNot(common.Dryrun)
 }
 
-func (cr *containerReference) CopyDir(destPath, srcPath string, useGitIgnore bool) common.Executor {
+func (cr *containerReference) CopyDir(destPath, srcPath string, useGitIgnore, skipGitDir bool) common.Executor {
 	return common.NewPipelineExecutor(
 		common.NewInfoExecutor("docker cp src=%s dst=%s", srcPath, destPath),
 		cr.connect(),
 		cr.find(),
-		cr.copyDir(destPath, srcPath, useGitIgnore),
+		cr.copyDir(destPath, srcPath, useGitIgnore, skipGitDir),
 		func(ctx context.Context) error {
 			// If this fails, then folders have wrong permissions on non root container
 			if cr.UID != 0 || cr.GID != 0 {
@@ -940,7 +940,7 @@ func (cr *containerReference) waitForCommand(ctx context.Context, resp client.Hi
 	}
 }
 
-func (cr *containerReference) copyDir(dstPath, srcPath string, useGitIgnore bool) common.Executor {
+func (cr *containerReference) copyDir(dstPath, srcPath string, useGitIgnore, skipGitDir bool) common.Executor {
 	return func(ctx context.Context) error {
 		if cr.id == "" {
 			return cr.missingContainerError("copy directory to %s", dstPath)
@@ -981,9 +981,10 @@ func (cr *containerReference) copyDir(dstPath, srcPath string, useGitIgnore bool
 		}
 
 		fc := &filecollector.FileCollector{
-			Ignorer:   ignorer,
-			SrcPath:   srcPath,
-			SrcPrefix: srcPrefix,
+			Ignorer:    ignorer,
+			SrcPath:    srcPath,
+			SrcPrefix:  srcPrefix,
+			SkipGitDir: skipGitDir,
 			Handler: &filecollector.TarCollector{
 				TarWriter: tw,
 				UID:       cr.UID,

act/container/docker_run_test.go

@@ -471,7 +471,7 @@ func TestRejectsMissingContainer(t *testing.T) {
 		assert.Contains(t, err.Error(), `container "job-1" does not exist`, op)
 	}
 	check("copyContent", cr.copyContent("/var/run/act", &FileEntry{Name: "x", Mode: 0o644})(ctx))
-	check("copyDir", cr.copyDir("/var/run/act", "/src", false)(ctx))
+	check("copyDir", cr.copyDir("/var/run/act", "/src", false, false)(ctx))
 	check("exec", cr.exec([]string{"echo"}, nil, "", "")(ctx))
 	_, err := cr.GetContainerArchive(ctx, "/var/run/act/x")
 	check("GetContainerArchive", err)

act/container/host_environment.go

@@ -92,7 +92,7 @@ func (e *HostEnvironment) Copy(destPath string, files ...*FileEntry) common.Exec
 	}
 }
 
-func (e *HostEnvironment) CopyDir(destPath, srcPath string, useGitIgnore bool) common.Executor {
+func (e *HostEnvironment) CopyDir(destPath, srcPath string, useGitIgnore, skipGitDir bool) common.Executor {
 	return func(ctx context.Context) error {
 		logger := common.Logger(ctx)
 		srcPrefix := filepath.Dir(srcPath)
@@ -110,9 +110,10 @@ func (e *HostEnvironment) CopyDir(destPath, srcPath string, useGitIgnore bool) c
 			ignorer = gitignore.NewMatcher(ps)
 		}
 		fc := &filecollector.FileCollector{
-			Ignorer:   ignorer,
-			SrcPath:   srcPath,
-			SrcPrefix: srcPrefix,
+			Ignorer:    ignorer,
+			SrcPath:    srcPath,
+			SrcPrefix:  srcPrefix,
+			SkipGitDir: skipGitDir,
 			Handler: &filecollector.CopyCollector{
 				DstDir: destPath,
 			},

act/container/host_environment_test.go

@@ -47,10 +47,32 @@ func TestCopyDir(t *testing.T) {
 	_ = os.MkdirAll(e.TmpDir, 0o700)
 	_ = os.MkdirAll(e.ToolCache, 0o700)
 	_ = os.MkdirAll(e.ActPath, 0o700)
-	err := e.CopyDir(e.Workdir, e.Path, true)(ctx)
+	err := e.CopyDir(e.Workdir, e.Path, true, false)(ctx)
 	assert.NoError(t, err)
 }
 
+func TestCopyDirSkipGitDir(t *testing.T) {
+	for name, skipGitDir := range map[string]bool{"kept for a workspace copy": false, "skipped for an action copy": true} {
+		t.Run(name, func(t *testing.T) {
+			src := filepath.Join(t.TempDir(), "action")
+			require.NoError(t, os.MkdirAll(filepath.Join(src, ".git", "objects"), 0o700))
+			require.NoError(t, os.WriteFile(filepath.Join(src, ".git", "objects", "pack"), []byte("x"), 0o600))
+			require.NoError(t, os.WriteFile(filepath.Join(src, "action.yml"), []byte("name: x\n"), 0o600))
+
+			dest := filepath.Join(t.TempDir(), "dest")
+			e := &HostEnvironment{StdOut: os.Stdout}
+			require.NoError(t, e.CopyDir(dest, src+string(filepath.Separator), false, skipGitDir)(context.Background()))
+
+			assert.FileExists(t, filepath.Join(dest, "action.yml"))
+			if skipGitDir {
+				assert.NoDirExists(t, filepath.Join(dest, ".git"))
+			} else {
+				assert.FileExists(t, filepath.Join(dest, ".git", "objects", "pack"))
+			}
+		})
+	}
+}
+
 func TestGetContainerArchive(t *testing.T) {
 	dir := t.TempDir()
 	ctx := context.Background()