Expose command line option to configure umask for directories and files

changelog/0.11.0_2022-02-10/issue-189

@@ -0,0 +1,6 @@
+Feature: Implement boolean flag "group-readable-repositores"
+
+A CLI option to write dirs and files with a group readable permission grant
+
+https://github.com/restic/rest-server/issues/189
+https://github.com/restic/rest-server/pull/190

cmd/rest-server/main.go

@@ -60,6 +60,7 @@ func init() {
 	flags.BoolVar(&server.PrivateRepos, "private-repos", server.PrivateRepos, "users can only access their private repo")
 	flags.BoolVar(&server.Prometheus, "prometheus", server.Prometheus, "enable Prometheus metrics")
 	flags.BoolVar(&server.PrometheusNoAuth, "prometheus-no-auth", server.PrometheusNoAuth, "disable auth for Prometheus /metrics endpoint")
+	flags.BoolVar(&server.GroupAccessibleRepos, "group-accessible-repositories", server.GroupAccessibleRepos, "make filesystem repo files group readable")
 }
 
 var version = "0.12.1-dev"
@@ -132,6 +133,10 @@ func runRoot(cmd *cobra.Command, args []string) error {
 		log.Println("Private repositories disabled")
 	}
 
+	if server.GroupAccessibleRepos {
+		log.Println("Repositories are group accessible")
+	}
+
 	enabledTLS, privateKey, publicKey, err := tlsSettings()
 	if err != nil {
 		return err

handlers.go

@@ -15,23 +15,24 @@
 
 // Server encapsulates the rest-server's settings and repo management logic
 type Server struct {
-	Path             string
-	HtpasswdPath     string
-	Listen           string
-	Log              string
-	CPUProfile       string
-	TLSKey           string
-	TLSCert          string
-	TLS              bool
-	NoAuth           bool
-	AppendOnly       bool
-	PrivateRepos     bool
-	Prometheus       bool
-	PrometheusNoAuth bool
-	Debug            bool
-	MaxRepoSize      int64
-	PanicOnError     bool
-	NoVerifyUpload   bool
+	Path                 string
+  HtpasswdPath         string
+	Listen               string
+	Log                  string
+	CPUProfile           string
+	TLSKey               string
+	TLSCert              string
+	TLS                  bool
+	NoAuth               bool
+	AppendOnly           bool
+	PrivateRepos         bool
+	Prometheus           bool
+	PrometheusNoAuth     bool
+	Debug                bool
+	MaxRepoSize          int64
+	PanicOnError         bool
+	NoVerifyUpload       bool
+	GroupAccessibleRepos bool
 
 	htpasswdFile *HtpasswdFile
 	quotaManager *quota.Manager
@@ -93,6 +94,7 @@
 		QuotaManager:   s.quotaManager, // may be nil
 		PanicOnError:   s.PanicOnError,
 		NoVerifyUpload: s.NoVerifyUpload,
+		GroupReadable:  s.GroupAccessibleRepos,
 		FsyncWarning:   &s.fsyncWarning,
 	}
 	if s.Prometheus {
@@ -158,7 +160,8 @@
 // splitURLPath splits the URL path into a folderPath of the subrepo, and
 // a remainder that can be passed to repo.Handler.
 // Example: /foo/bar/locks/0123... will be split into:
-//          ["foo", "bar"] and "/locks/0123..."
+//
+//	["foo", "bar"] and "/locks/0123..."
 func splitURLPath(urlPath string, maxDepth int) (folderPath []string, remainder string) {
 	if !strings.HasPrefix(urlPath, "/") {
 		// Really should start with "/"

repo/repo.go

@@ -29,8 +29,6 @@
 type Options struct {
 	AppendOnly     bool // if set, delete actions are not allowed
 	Debug          bool
-	DirMode        os.FileMode
-	FileMode       os.FileMode
 	NoVerifyUpload bool
 
 	// If set, we will panic when an internal server error happens. This
@@ -39,29 +37,51 @@
 
 	BlobMetricFunc BlobMetricFunc
 	QuotaManager   *quota.Manager
-	FsyncWarning   *sync.Once
+  FsyncWarning   *sync.Once
+
+  // If set, we will panic when an internal server error happens. This
+	// makes it easier to debug such errors.
+	GroupReadable bool
+
+	dirMode  os.FileMode
+	fileMode os.FileMode
 }
 
-// DefaultDirMode is the file mode used for directory creation if not
+// DefaultGroupReadable shows if files and dirs written should be group readable
 // overridden in the Options
+const DefaultGroupReadable = false
+
+// DefaultDirMode is the file mode used for directory creation by default
 const DefaultDirMode os.FileMode = 0700
 
-// DefaultFileMode is the file mode used for file creation if not
-// overridden in the Options
+// DefaultFileMode is the file mode used for file creation by default
 const DefaultFileMode os.FileMode = 0600
 
+// GroupReadableDirMode is the file mode used for directory creation if group readable
+const GroupReadableDirMode os.FileMode = 0750
+
+// GroupReadableFileMode is the file mode used for directory creation if group readable
+const GroupReadableFileMode os.FileMode = 0640
+
 // New creates a new Handler for a single Restic backup repo.
 // path is the full filesystem path to this repo directory.
 // opt is a set of options.
 func New(path string, opt Options) (*Handler, error) {
 	if path == "" {
 		return nil, fmt.Errorf("path is required")
 	}
-	if opt.DirMode == 0 {
-		opt.DirMode = DefaultDirMode
-	}
-	if opt.FileMode == 0 {
-		opt.FileMode = DefaultFileMode
+	// if opt.dirMode == 0 {
+	// 	opt.dirMode = DefaultDirMode
+	// }
+	// if opt.fileMode == 0 {
+	// 	opt.fileMode = DefaultFileMode
+	// }
+	if opt.GroupReadable {
+		opt.dirMode = GroupReadableDirMode
+		opt.fileMode = GroupReadableFileMode
+	} else {
+		opt.dirMode = DefaultDirMode
+		opt.fileMode = DefaultFileMode
 	}
 	h := Handler{
 		path: path,
@@ -289,7 +309,7 @@
 	}
 	cfg := h.getSubPath("config")
 
-	f, err := os.OpenFile(cfg, os.O_CREATE|os.O_WRONLY|os.O_EXCL, h.opt.FileMode)
+	f, err := os.OpenFile(cfg, os.O_CREATE|os.O_WRONLY|os.O_EXCL, h.opt.fileMode)
 	if err != nil && os.IsExist(err) {
 		if h.opt.Debug {
 			log.Print(err)
@@ -545,15 +565,15 @@
 	}
 
 	tmpFn := filepath.Join(filepath.Dir(path), objectID+".rest-server-temp")
-	tf, err := tempFile(tmpFn, h.opt.FileMode)
+	tf, err := tempFile(tmpFn, h.opt.fileMode)
 	if os.IsNotExist(err) {
 		// the error is caused by a missing directory, create it and retry
-		mkdirErr := os.MkdirAll(filepath.Dir(path), h.opt.DirMode)
+		mkdirErr := os.MkdirAll(filepath.Dir(path), h.opt.dirMode)
 		if mkdirErr != nil {
 			log.Print(mkdirErr)
 		} else {
 			// try again
-			tf, err = tempFile(tmpFn, h.opt.FileMode)
+			tf, err = tempFile(tmpFn, h.opt.fileMode)
 		}
 	}
 	if err != nil {
@@ -750,21 +770,21 @@
 
 	log.Printf("Creating repository directories in %s\n", h.path)
 
-	if err := os.MkdirAll(h.path, h.opt.DirMode); err != nil {
+	if err := os.MkdirAll(h.path, h.opt.dirMode); err != nil {
 		h.internalServerError(w, err)
 		return
 	}
 
 	for _, d := range ObjectTypes {
-		if err := os.Mkdir(filepath.Join(h.path, d), h.opt.DirMode); err != nil && !os.IsExist(err) {
+		if err := os.Mkdir(filepath.Join(h.path, d), h.opt.dirMode); err != nil && !os.IsExist(err) {
 			h.internalServerError(w, err)
 			return
 		}
 	}
 
 	for i := 0; i < 256; i++ {
 		dirPath := filepath.Join(h.path, "data", fmt.Sprintf("%02x", i))
-		if err := os.Mkdir(dirPath, h.opt.DirMode); err != nil && !os.IsExist(err) {
+		if err := os.Mkdir(dirPath, h.opt.dirMode); err != nil && !os.IsExist(err) {
 			h.internalServerError(w, err)
 			return
 		}