Consider prefix rules when pruning WebDAV storages (#79)

README.md

@@ -156,6 +156,11 @@ You can populate below template according to your requirements and use it as you
 
 # BACKUP_FROM_SNAPSHOT="false"
 
+# By default, the `/backup` directory inside the container will be backed up.
+# In case you need to use a custom location, set `BACKUP_SOURCES`.
+
+# BACKUP_SOURCES="/other/location"
+
 ########### BACKUP STORAGE
 
 # The name of the remote bucket that should be used for storing backups. If
@@ -658,7 +663,7 @@ In case you are using a socket proxy, it must support `GET` and `POST` requests
 
 Multiple backup schedules with different configuration can be configured by mounting an arbitrary number of configuration files (using the `.env` format) into `/etc/dockervolumebackup/conf.d`:
 
-```
+```yml
 version: '3'
 
 services:

cmd/backup/exec.go

@@ -1,6 +1,9 @@
 // Copyright 2022 - Offen Authors <hioffen@posteo.de>
 // SPDX-License-Identifier: MPL-2.0
 
+// Portions of this file are taken and adapted from `moby`, Copyright 2012-2017 Docker, Inc.
+// Licensed under the Apache 2.0 License: https://github.com/moby/moby/blob/8e610b2b55bfd1bfa9436ab110d311f5e8a74dcb/LICENSE
+
 package main
 
 import (

cmd/backup/script.go

@@ -12,6 +12,7 @@ import (
 	"os"
 	"path"
 	"path/filepath"
+	"strings"
 	"text/template"
 	"time"
 
@@ -580,6 +581,9 @@ func (s *script) pruneBackups() error {
 		var matches []fs.FileInfo
 		var lenCandidates int
 		for _, candidate := range candidates {
+			if !strings.HasPrefix(candidate.Name(), s.c.BackupPruningPrefix) {
+				continue
+			}
 			lenCandidates++
 			if candidate.ModTime().Before(deadline) {
 				matches = append(matches, candidate)