Use os.TempDir() for temporary directory in default path

README.md

@@ -73,7 +73,7 @@ Flags:
   -v, --version              version for rest-server
 ```
 
-By default the server persists backup data in `/tmp/restic`.  To start the server with a custom persistence directory and with authentication disabled:
+By default the server persists backup data in the O.S. temporary directory (`/tmp/restic` on Linux/BSD and others, in `%TEMP%\\restic` in Windows, etc). **If `rest-server` is launched using the default path, all backups will be lost**. To start the server with a custom persistence directory and with authentication disabled:
 
 ```sh
 rest-server --path /user/home/backup --no-auth

changelog/unreleased/pull-158

@@ -0,0 +1,8 @@
+Bugfix: Use platform-specific temporary directory in default path
+
+Instead of using hardcoded value for temporary directory, rest-server now uses
+Go standard library functions to retrieve the temporary directory path for the
+current platform.
+
+https://github.com/restic/rest-server/issues/157
+https://github.com/restic/rest-server/pull/158

cmd/rest-server/main.go

@@ -27,7 +27,7 @@ var cmdRoot = &cobra.Command{
 }
 
 var server = restserver.Server{
-	Path:   "/tmp/restic",
+	Path:   filepath.Join(os.TempDir(), "restic"),
 	Listen: ":8000",
 }