Update README TOC

* Added custom notification messages using text/template

* Change notification template path and removed automatic newline trim

* Added stats and changed structure of template params

* Stat file hotfix

* Embedded and fixed default notification templates


Fix

* Changed Output to LogOutput

* Changed stats integer to unsigned

* Bytes formatting in template func


fix

* Changed Archives to Storages

* Removed unecessary sleep for pruning leeway

* Set EndTime after pruning is completed

* Added custom notifications documentation

* Added 5s sleep in swarm test

* Fixed documentation

* Dockerfile copies all files in cmd/backup

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,20 @@
+* **I'm submitting a ...**
+  - [ ] bug report
+  - [ ] feature request
+  - [ ] support request
+
+* **What is the current behavior?**
+
+* **If the current behavior is a bug, please provide the configuration and steps to reproduce and if possible a minimal demo of the problem.**
+
+* **What is the expected behavior?**
+
+* **What is the motivation / use case for changing the behavior?**
+
+* **Please tell us about your environment:**
+  
+  - Image version:
+  - Docker version: 
+  - docker-compose version:
+
+* **Other information** (e.g. detailed explanation, stacktraces, related issues, suggestions how to fix, links for us to have context, eg. stackoverflow, etc)

Dockerfile

@@ -6,10 +6,10 @@ FROM golang:1.17-alpine as builder
 WORKDIR /app
 COPY go.mod go.sum ./
 RUN go mod download
-COPY cmd/backup/main.go ./cmd/backup/main.go
+COPY cmd/backup ./cmd/backup/
 RUN go build -o backup cmd/backup/main.go
 
-FROM alpine:3.14
+FROM alpine:3.15
 
 WORKDIR /root
 

README.md

@@ -1,9 +1,13 @@
+<a href="https://www.offen.dev/">
+    <img src="https://offen.github.io/press-kit/offen-material/gfx-GitHub-Offen-logo.svg" alt="Offen logo" title="Offen" width="150px"/>
+</a>
+
 # docker-volume-backup
 
 Backup Docker volumes locally or to any S3 compatible storage.
 
 The [offen/docker-volume-backup](https://hub.docker.com/r/offen/docker-volume-backup) Docker image can be used as a lightweight (below 15MB) sidecar container to an existing Docker setup.
-It handles __recurring or one-off backups of Docker volumes__ to a __local directory__ or __any S3 compatible storage__ (or both), and __rotates away old backups__ if configured. It also supports __encrypting your backups using GPG__ and __sending notifications for failed backup runs__.
+It handles __recurring or one-off backups of Docker volumes__ to a __local directory__, __any S3 or WebDAV compatible storage (or any combination) and rotates away old backups__ if configured. It also supports __encrypting your backups using GPG__ and __sending notifications for failed backup runs__.
 
 <!-- MarkdownTOC -->
 
@@ -15,6 +19,7 @@ It handles __recurring or one-off backups of Docker volumes__ to a __local direc
   - [Stopping containers during backup](#stopping-containers-during-backup)
   - [Automatically pruning old backups](#automatically-pruning-old-backups)
   - [Send email notifications on failed backup runs](#send-email-notifications-on-failed-backup-runs)
+  - [Customize notifications](#customize-notifications)
   - [Encrypting your backup using GPG](#encrypting-your-backup-using-gpg)
   - [Restoring a volume from a backup](#restoring-a-volume-from-a-backup)
   - [Set the timezone the container runs in](#set-the-timezone-the-container-runs-in)
@@ -23,7 +28,9 @@ It handles __recurring or one-off backups of Docker volumes__ to a __local direc
   - [Update deprecated email configuration](#update-deprecated-email-configuration)
 - [Recipes](#recipes)
   - [Backing up to AWS S3](#backing-up-to-aws-s3)
+  - [Backing up to Filebase](#backing-up-to-filebase)
   - [Backing up to MinIO](#backing-up-to-minio)
+  - [Backing up to WebDAV](#backing-up-to-webdav)
   - [Backing up locally](#backing-up-locally)
   - [Backing up to AWS S3 as well as locally](#backing-up-to-aws-s3-as-well-as-locally)
   - [Running on a custom cron schedule](#running-on-a-custom-cron-schedule)
@@ -130,7 +137,7 @@ You can populate below template according to your requirements and use it as you
 # Please note that you will need to escape the `$` when providing the value
 # in a docker-compose.yml file, i.e. using $$VAR instead of $VAR.
 
-# BACKUP_FILENAME_TEMPLATE="true"
+# BACKUP_FILENAME_EXPAND="true"
 
 # When storing local backups, a symlink to the latest backup can be created
 # in case a value is given for this key. This has no effect on remote backups.
@@ -151,6 +158,11 @@ You can populate below template according to your requirements and use it as you
 
 # AWS_S3_BUCKET_NAME="backup-bucket"
 
+# If you want to store the backup in a non-root location on your bucket
+# you can provide a path. The path must not contain a leading slash.
+
+# AWS_S3_PATH="my/backup/location"
+
 # Define credentials for authenticating against the backup storage and a bucket
 # name. Although all of these keys are `AWS`-prefixed, the setup can be used
 # with any S3 compatible storage.
@@ -185,6 +197,25 @@ You can populate below template according to your requirements and use it as you
 
 # AWS_ENDPOINT_INSECURE="true"
 
+# You can also backup files to any WebDAV server:
+
+# The URL of the remote WebDAV server
+
+# WEBDAV_URL="https://webdav.example.com"
+
+# The Directory to place the backups to on the WebDAV server.
+# If the path is not present on the server it will be created.
+
+# WEBDAV_PATH="/my/directory/"
+
+# The username for the WebDAV server
+
+# WEBDAV_USERNAME="user"
+
+# The password for the WebDAV server
+
+# WEBDAV_PASSWORD="password"
+
 # In addition to storing backups remotely, you can also keep local copies.
 # Pass a container-local path to store your backups if needed. You also need to
 # mount a local folder or Docker volume into that location (`/archive`
@@ -378,6 +409,30 @@ Refer to the documentation of [shoutrrr][shoutrrr-docs] to find out about option
 
 [shoutrrr-docs]: https://containrrr.dev/shoutrrr/v0.5/services/overview/
 
+### Customize notifications
+
+The title and body of the notifications can be easily tailored to your needs using [go templates](https://pkg.go.dev/text/template).
+Templates must be mounted inside the container in `/etc/dockervolumebackup/notifications.d/`: any file inside this directory will be parsed.
+
+The files have to define [nested templates](https://pkg.go.dev/text/template#hdr-Nested_template_definitions) in order to override the original values. An example:
+```
+{{ define "title_success" -}}
+✅ Successfully ran backup {{ .Config.BackupStopContainerLabel }}
+{{- end }}
+
+{{ define "body_success" -}}
+▶️ Start time: {{ .Stats.StartTime | formatTime }}
+⏹️ End time: {{ .Stats.EndTime | formatTime }}
+⌛ Took time: {{ .Stats.TookTime }}
+🛑 Stopped containers: {{ .Stats.Containers.Stopped }}/{{ .Stats.Containers.All }} ({{ .Stats.Containers.StopErrors }} errors)
+⚖️ Backup size: {{ .Stats.BackupFile.Size | formatBytesBin }} / {{ .Stats.BackupFile.Size | formatBytesDec }}
+🗑️ Pruned backups: {{ .Stats.Storages.Local.Pruned }}/{{ .Stats.Storages.Local.Total }} ({{ .Stats.Storages.Local.PruneErrors }} errors)
+{{- end }}
+```
+
+Overridable template names are: `title_success`, `body_success`, `title_failure`, `body_failure`.
+
+For a full list of available variables and functions, see [this page](https://github.com/offen/docker-volume-backup/blob/master/docs/NOTIFICATION-TEMPLATES.md).
 
 ### Encrypting your backup using GPG
 
@@ -399,12 +454,12 @@ In case you need to restore a volume from a backup, the most straight forward pr
   ```console
   tar -C /tmp -xvf  backup.tar.gz
   ```
-- Using a temporary one-off container, mount the volume (the example assumes it's named `data`) and copy over the backup. Make sure you copy the correct path level (this depends on how you mount your volume into the backup container), you might need to strip some leading elements
+- Using a temporary once-off container, mount the volume (the example assumes it's named `data`) and copy over the backup. Make sure you copy the correct path level (this depends on how you mount your volume into the backup container), you might need to strip some leading elements
   ```console
-  docker run -d --name backup_restore -v data:/backup_restore alpine
-  docker cp /tmp/backup/data-backup backup_restore:/backup_restore
-  docker stop backup_restore
-  docker rm backup_restore
+  docker run -d --name temp_restore_container -v data:/backup_restore alpine
+  docker cp /tmp/backup/data-backup temp_restore_container:/backup_restore
+  docker stop temp_restore_container
+  docker rm temp_restore_container
   ```
 - Restart the container(s) that are using the volume
 
@@ -504,6 +559,28 @@ volumes:
   data:
 ```
 
+### Backing up to Filebase
+
+```yml
+version: '3'
+
+services:
+  # ... define other services using the `data` volume here
+  backup:
+    image: offen/docker-volume-backup:latest
+    environment:
+      AWS_ENDPOINT: s3.filebase.com
+      AWS_BUCKET_NAME: filebase-bucket
+      AWS_ACCESS_KEY_ID: FILEBASE-ACCESS-KEY
+      AWS_SECRET_ACCESS_KEY: FILEBASE-SECRET-KEY
+    volumes:
+      - data:/backup/my-app-backup:ro
+      - /var/run/docker.sock:/var/run/docker.sock:ro
+
+volumes:
+  data:
+```
+
 ### Backing up to MinIO
 
 ```yml
@@ -526,6 +603,28 @@ volumes:
   data:
 ```
 
+### Backing up to WebDAV
+
+```yml
+version: '3'
+
+services:
+  # ... define other services using the `data` volume here
+  backup:
+    image: offen/docker-volume-backup:latest
+    environment:
+      WEBDAV_URL: https://webdav.mydomain.me
+      WEBDAV_PATH: /my/directory/
+      WEBDAV_USERNAME: user
+      WEBDAV_PASSWORD: password
+    volumes:
+      - data:/backup/my-app-backup:ro
+      - /var/run/docker.sock:/var/run/docker.sock:ro
+
+volumes:
+  data:
+```
+
 ### Backing up locally
 
 ```yml

cmd/backup/main.go

@@ -6,14 +6,17 @@ package main
 import (
 	"bytes"
 	"context"
+	_ "embed"
 	"errors"
 	"fmt"
 	"io"
+	"io/fs"
 	"os"
 	"path"
 	"path/filepath"
 	"sort"
 	"strings"
+	"text/template"
 	"time"
 
 	"github.com/containrrr/shoutrrr"
@@ -31,9 +34,13 @@ import (
 	"github.com/minio/minio-go/v7/pkg/credentials"
 	"github.com/otiai10/copy"
 	"github.com/sirupsen/logrus"
+	"github.com/studio-b12/gowebdav"
 	"golang.org/x/crypto/openpgp"
 )
 
+//go:embed notifications.tmpl
+var defaultNotifications string
+
 func main() {
 	unlock := lock("/var/lock/dockervolumebackup.lock")
 	defer unlock()
@@ -81,26 +88,76 @@ func main() {
 	s.must(s.encryptBackup())
 	s.must(s.copyBackup())
 	s.must(s.pruneOldBackups())
+	s.stats.EndTime = time.Now()
+	s.stats.TookTime = s.stats.EndTime.Sub(s.stats.EndTime)
 }
 
 // script holds all the stateful information required to orchestrate a
 // single backup run.
 type script struct {
 	cli          *client.Client
-	mc        *minio.Client
+	minioClient  *minio.Client
+	webdavClient *gowebdav.Client
 	logger       *logrus.Logger
 	sender       *router.ServiceRouter
+	template     *template.Template
 	hooks        []hook
 	hookLevel    hookLevel
 
-	start  time.Time
 	file  string
-	output *bytes.Buffer
+	stats *Stats
 
-	c *config
+	c *Config
 }
 
-type config struct {
+// ContainersStats stats about the docker containers
+type ContainersStats struct {
+	All        uint
+	ToStop     uint
+	Stopped    uint
+	StopErrors uint
+}
+
+// BackupFileStats stats about the created backup file
+type BackupFileStats struct {
+	Name     string
+	FullPath string
+	Size     uint64
+}
+
+// StorageStats stats about the status of an archival directory
+type StorageStats struct {
+	Total       uint
+	Pruned      uint
+	PruneErrors uint
+}
+
+// StoragesStats stats about each possible archival location (Local, WebDAV, S3)
+type StoragesStats struct {
+	Local  StorageStats
+	WebDAV StorageStats
+	S3     StorageStats
+}
+
+// Stats global stats regarding script execution
+type Stats struct {
+	StartTime  time.Time
+	EndTime    time.Time
+	TookTime   time.Duration
+	LogOutput  *bytes.Buffer
+	Containers ContainersStats
+	BackupFile BackupFileStats
+	Storages   StoragesStats
+}
+
+// NotificationData data to be passed to the notification templates
+type NotificationData struct {
+	Error  error
+	Config *Config
+	Stats  *Stats
+}
+
+type Config struct {
 	BackupSources              string        `split_words:"true" default:"/backup"`
 	BackupFilename             string        `split_words:"true" default:"backup-%Y-%m-%dT%H-%M-%S.tar.gz"`
 	BackupFilenameExpand       bool          `split_words:"true"`
@@ -112,6 +169,7 @@ type config struct {
 	BackupStopContainerLabel   string        `split_words:"true" default:"true"`
 	BackupFromSnapshot         bool          `split_words:"true"`
 	AwsS3BucketName            string        `split_words:"true"`
+	AwsS3Path                  string        `split_words:"true"`
 	AwsEndpoint                string        `split_words:"true" default:"s3.amazonaws.com"`
 	AwsEndpointProto           string        `split_words:"true" default:"https"`
 	AwsEndpointInsecure        bool          `split_words:"true"`
@@ -127,6 +185,10 @@ type config struct {
 	EmailSMTPPort              int           `envconfig:"EMAIL_SMTP_PORT" default:"587"`
 	EmailSMTPUsername          string        `envconfig:"EMAIL_SMTP_USERNAME"`
 	EmailSMTPPassword          string        `envconfig:"EMAIL_SMTP_PASSWORD"`
+	WebdavUrl                  string        `split_words:"true"`
+	WebdavPath                 string        `split_words:"true" default:"/"`
+	WebdavUsername             string        `split_words:"true"`
+	WebdavPassword             string        `split_words:"true"`
 }
 
 var msgBackupFailed = "backup run failed"
@@ -138,15 +200,18 @@ var msgBackupFailed = "backup run failed"
 func newScript() (*script, error) {
 	stdOut, logBuffer := buffer(os.Stdout)
 	s := &script{
-		c: &config{},
+		c: &Config{},
 		logger: &logrus.Logger{
 			Out:       stdOut,
 			Formatter: new(logrus.TextFormatter),
 			Hooks:     make(logrus.LevelHooks),
 			Level:     logrus.InfoLevel,
 		},
-		start:  time.Now(),
-		output: logBuffer,
+		stats: &Stats{
+			StartTime: time.Now(),
+			LogOutput: logBuffer,
+			Storages:  StoragesStats{},
+		},
 	}
 
 	if err := envconfig.Process("", s.c); err != nil {
@@ -159,7 +224,7 @@ func newScript() (*script, error) {
 		s.c.BackupLatestSymlink = os.ExpandEnv(s.c.BackupLatestSymlink)
 		s.c.BackupPruningPrefix = os.ExpandEnv(s.c.BackupPruningPrefix)
 	}
-	s.file = timeutil.Strftime(&s.start, s.file)
+	s.file = timeutil.Strftime(&s.stats.StartTime, s.file)
 
 	_, err := os.Stat("/var/run/docker.sock")
 	if !os.IsNotExist(err) {
@@ -206,7 +271,16 @@ func newScript() (*script, error) {
 		if err != nil {
 			return nil, fmt.Errorf("newScript: error setting up minio client: %w", err)
 		}
-		s.mc = mc
+		s.minioClient = mc
+	}
+
+	if s.c.WebdavUrl != "" {
+		if s.c.WebdavUsername == "" || s.c.WebdavPassword == "" {
+			return nil, errors.New("newScript: WEBDAV_URL is defined, but no credentials were provided")
+		} else {
+			webdavClient := gowebdav.NewClient(s.c.WebdavUrl, s.c.WebdavUsername, s.c.WebdavPassword)
+			s.webdavClient = webdavClient
+		}
 	}
 
 	if s.c.EmailNotificationRecipient != "" {
@@ -256,6 +330,31 @@ func newScript() (*script, error) {
 		})
 	}
 
+	tmpl := template.New("")
+	tmpl.Funcs(template.FuncMap{
+		"formatTime": func(t time.Time) string {
+			return t.Format(time.RFC3339)
+		},
+		"formatBytesDec": func(bytes uint64) string {
+			return formatBytes(bytes, true)
+		},
+		"formatBytesBin": func(bytes uint64) string {
+			return formatBytes(bytes, false)
+		},
+	})
+	tmpl, err = tmpl.Parse(defaultNotifications)
+	if err != nil {
+		return nil, fmt.Errorf("newScript: unable to parse default notifications templates: %w", err)
+	}
+
+	if _, err := os.Stat("/etc/dockervolumebackup/notifications.d"); err == nil {
+		tmpl, err = tmpl.ParseGlob("/etc/dockervolumebackup/notifications.d/*.*")
+		if err != nil {
+			return nil, fmt.Errorf("newScript: unable to parse user defined notifications templates: %w", err)
+		}
+	}
+	s.template = tmpl
+
 	return s, nil
 }
 
@@ -266,28 +365,39 @@ func (s *script) registerHook(level hookLevel, action func(err error) error) {
 	s.hooks = append(s.hooks, hook{level, action})
 }
 
-// notifyFailure sends a notification about a failed backup run
-func (s *script) notifyFailure(err error) error {
-	body := fmt.Sprintf(
-		"Running docker-volume-backup failed with error: %s\n\nLog output of the failed run was:\n\n%s\n", err, s.output.String(),
-	)
-	title := fmt.Sprintf("Failure running docker-volume-backup at %s", s.start.Format(time.RFC3339))
-	if err := s.sendNotification(title, body); err != nil {
+// notify sends a notification using the given title and body templates.
+// Automatically creates notification data, adding the given error
+func (s *script) notify(titleTemplate string, bodyTemplate string, err error) error {
+	params := NotificationData{
+		Error:  err,
+		Stats:  s.stats,
+		Config: s.c,
+	}
+
+	titleBuf := &bytes.Buffer{}
+	if err := s.template.ExecuteTemplate(titleBuf, titleTemplate, params); err != nil {
+		return fmt.Errorf("notifyFailure: error executing %s template: %w", titleTemplate, err)
+	}
+
+	bodyBuf := &bytes.Buffer{}
+	if err := s.template.ExecuteTemplate(bodyBuf, bodyTemplate, params); err != nil {
+		return fmt.Errorf("notifyFailure: error executing %s template: %w", bodyTemplate, err)
+	}
+
+	if err := s.sendNotification(titleBuf.String(), bodyBuf.String()); err != nil {
 		return fmt.Errorf("notifyFailure: error notifying: %w", err)
 	}
 	return nil
 }
 
+// notifyFailure sends a notification about a failed backup run
+func (s *script) notifyFailure(err error) error {
+	return s.notify("title_failure", "body_failure", err)
+}
+
 // notifyFailure sends a notification about a successful backup run
 func (s *script) notifySuccess() error {
-	title := fmt.Sprintf("Success running docker-volume-backup at %s", s.start.Format(time.RFC3339))
-	body := fmt.Sprintf(
-		"Running docker-volume-backup succeeded.\n\nLog output was:\n\n%s\n", s.output.String(),
-	)
-	if err := s.sendNotification(title, body); err != nil {
-		return fmt.Errorf("notifySuccess: error notifying: %w", err)
-	}
-	return nil
+	return s.notify("title_success", "body_success", nil)
 }
 
 // sendNotification sends a notification to all configured third party services
@@ -365,6 +475,12 @@ func (s *script) stopContainers() (func() error, error) {
 		)
 	}
 
+	s.stats.Containers = ContainersStats{
+		All:     uint(len(allContainers)),
+		ToStop:  uint(len(containersToStop)),
+		Stopped: uint(len(stoppedContainers)),
+	}
+
 	return func() error {
 		servicesRequiringUpdate := map[string]struct{}{}
 
@@ -508,8 +624,19 @@ func (s *script) encryptBackup() error {
 // as per the given configuration.
 func (s *script) copyBackup() error {
 	_, name := path.Split(s.file)
-	if s.mc != nil {
-		if _, err := s.mc.FPutObject(context.Background(), s.c.AwsS3BucketName, name, s.file, minio.PutObjectOptions{
+	if stat, err := os.Stat(s.file); err != nil {
+		return fmt.Errorf("copyBackup: unable to stat backup file: %w", err)
+	} else {
+		size := stat.Size()
+		s.stats.BackupFile = BackupFileStats{
+			Size:     uint64(size),
+			Name:     name,
+			FullPath: s.file,
+		}
+	}
+
+	if s.minioClient != nil {
+		if _, err := s.minioClient.FPutObject(context.Background(), s.c.AwsS3BucketName, filepath.Join(s.c.AwsS3Path, name), s.file, minio.PutObjectOptions{
 			ContentType: "application/tar+gzip",
 		}); err != nil {
 			return fmt.Errorf("copyBackup: error uploading backup to remote storage: %w", err)
@@ -517,6 +644,20 @@ func (s *script) copyBackup() error {
 		s.logger.Infof("Uploaded a copy of backup `%s` to bucket `%s`.", s.file, s.c.AwsS3BucketName)
 	}
 
+	if s.webdavClient != nil {
+		bytes, err := os.ReadFile(s.file)
+		if err != nil {
+			return fmt.Errorf("copyBackup: error reading the file to be uploaded: %w", err)
+		}
+		if err := s.webdavClient.MkdirAll(s.c.WebdavPath, 0644); err != nil {
+			return fmt.Errorf("copyBackup: error creating directory '%s' on WebDAV server: %w", s.c.WebdavPath, err)
+		}
+		if err := s.webdavClient.Write(filepath.Join(s.c.WebdavPath, name), bytes, 0644); err != nil {
+			return fmt.Errorf("copyBackup: error uploading the file to WebDAV server: %w", err)
+		}
+		s.logger.Infof("Uploaded a copy of backup `%s` to WebDAV-URL '%s' at path '%s'.", s.file, s.c.WebdavUrl, s.c.WebdavPath)
+	}
+
 	if _, err := os.Stat(s.c.BackupArchive); !os.IsNotExist(err) {
 		if err := copyFile(s.file, path.Join(s.c.BackupArchive, name)); err != nil {
 			return fmt.Errorf("copyBackup: error copying file to local archive: %w", err)
@@ -544,15 +685,11 @@ func (s *script) pruneOldBackups() error {
 		return nil
 	}
 
-	if s.c.BackupPruningLeeway != 0 {
-		s.logger.Infof("Sleeping for %s before pruning backups.", s.c.BackupPruningLeeway)
-		time.Sleep(s.c.BackupPruningLeeway)
-	}
+	deadline := time.Now().AddDate(0, 0, -int(s.c.BackupRetentionDays)).Add(s.c.BackupPruningLeeway)
 
-	deadline := time.Now().AddDate(0, 0, -int(s.c.BackupRetentionDays))
-
-	if s.mc != nil {
-		candidates := s.mc.ListObjects(context.Background(), s.c.AwsS3BucketName, minio.ListObjectsOptions{
+	// Prune minio/S3 backups
+	if s.minioClient != nil {
+		candidates := s.minioClient.ListObjects(context.Background(), s.c.AwsS3BucketName, minio.ListObjectsOptions{
 			WithMetadata: true,
 			Prefix:       s.c.BackupPruningPrefix,
 		})
@@ -572,6 +709,10 @@ func (s *script) pruneOldBackups() error {
 			}
 		}
 
+		s.stats.Storages.S3 = StorageStats{
+			Total:  uint(lenCandidates),
+			Pruned: uint(len(matches)),
+		}
 		if len(matches) != 0 && len(matches) != lenCandidates {
 			objectsCh := make(chan minio.ObjectInfo)
 			go func() {
@@ -580,13 +721,14 @@ func (s *script) pruneOldBackups() error {
 				}
 				close(objectsCh)
 			}()
-			errChan := s.mc.RemoveObjects(context.Background(), s.c.AwsS3BucketName, objectsCh, minio.RemoveObjectsOptions{})
+			errChan := s.minioClient.RemoveObjects(context.Background(), s.c.AwsS3BucketName, objectsCh, minio.RemoveObjectsOptions{})
 			var removeErrors []error
 			for result := range errChan {
 				if result.Err != nil {
 					removeErrors = append(removeErrors, result.Err)
 				}
 			}
+			s.stats.Storages.S3.PruneErrors = uint(len(removeErrors))
 
 			if len(removeErrors) != 0 {
 				return fmt.Errorf(
@@ -595,10 +737,11 @@ func (s *script) pruneOldBackups() error {
 					join(removeErrors...),
 				)
 			}
+
 			s.logger.Infof(
 				"Pruned %d out of %d remote backup(s) as their age exceeded the configured retention period of %d days.",
-				len(matches),
-				lenCandidates,
+				s.stats.Storages.S3.Pruned,
+				s.stats.Storages.S3.Total,
 				s.c.BackupRetentionDays,
 			)
 		} else if len(matches) != 0 && len(matches) == lenCandidates {
@@ -612,6 +755,57 @@ func (s *script) pruneOldBackups() error {
 		}
 	}
 
+	// Prune WebDAV backups
+	if s.webdavClient != nil {
+		candidates, err := s.webdavClient.ReadDir(s.c.WebdavPath)
+		if err != nil {
+			return fmt.Errorf("pruneOldBackups: error looking up candidates from remote storage: %w", err)
+		}
+		var matches []fs.FileInfo
+		var lenCandidates int
+		for _, candidate := range candidates {
+			lenCandidates++
+			if candidate.ModTime().Before(deadline) {
+				matches = append(matches, candidate)
+			}
+		}
+
+		s.stats.Storages.WebDAV = StorageStats{
+			Total:  uint(lenCandidates),
+			Pruned: uint(len(matches)),
+		}
+		if len(matches) != 0 && len(matches) != lenCandidates {
+			var removeErrors []error
+			for _, match := range matches {
+				if err := s.webdavClient.Remove(filepath.Join(s.c.WebdavPath, match.Name())); err != nil {
+					removeErrors = append(removeErrors, err)
+				} else {
+					s.logger.Infof("Pruned %s from WebDAV: %s", match.Name(), filepath.Join(s.c.WebdavUrl, s.c.WebdavPath))
+				}
+			}
+			s.stats.Storages.WebDAV.PruneErrors = uint(len(removeErrors))
+			if len(removeErrors) != 0 {
+				return fmt.Errorf(
+					"pruneOldBackups: %d error(s) removing files from remote storage: %w",
+					len(removeErrors),
+					join(removeErrors...),
+				)
+			}
+			s.logger.Infof(
+				"Pruned %d out of %d remote backup(s) as their age exceeded the configured retention period of %d days.",
+				s.stats.Storages.WebDAV.Pruned,
+				s.stats.Storages.WebDAV.Total,
+				s.c.BackupRetentionDays,
+			)
+		} else if len(matches) != 0 && len(matches) == lenCandidates {
+			s.logger.Warnf("The current configuration would delete all %d remote backup copies.", len(matches))
+			s.logger.Warn("Refusing to do so, please check your configuration.")
+		} else {
+			s.logger.Infof("None of %d remote backup(s) were pruned.", lenCandidates)
+		}
+	}
+
+	// Prune local backups
 	if _, err := os.Stat(s.c.BackupArchive); !os.IsNotExist(err) {
 		globPattern := path.Join(
 			s.c.BackupArchive,
@@ -657,6 +851,10 @@ func (s *script) pruneOldBackups() error {
 			}
 		}
 
+		s.stats.Storages.Local = StorageStats{
+			Total:  uint(len(candidates)),
+			Pruned: uint(len(matches)),
+		}
 		if len(matches) != 0 && len(matches) != len(candidates) {
 			var removeErrors []error
 			for _, match := range matches {
@@ -665,6 +863,7 @@ func (s *script) pruneOldBackups() error {
 				}
 			}
 			if len(removeErrors) != 0 {
+				s.stats.Storages.Local.PruneErrors = uint(len(removeErrors))
 				return fmt.Errorf(
 					"pruneOldBackups: %d error(s) deleting local files, starting with: %w",
 					len(removeErrors),
@@ -673,8 +872,8 @@ func (s *script) pruneOldBackups() error {
 			}
 			s.logger.Infof(
 				"Pruned %d out of %d local backup(s) as their age exceeded the configured retention period of %d days.",
-				len(matches),
-				len(candidates),
+				s.stats.Storages.Local.Pruned,
+				s.stats.Storages.Local.Total,
 				s.c.BackupRetentionDays,
 			)
 		} else if len(matches) != 0 && len(matches) == len(candidates) {
@@ -792,6 +991,26 @@ func join(errs ...error) error {
 	return errors.New("[" + strings.Join(msgs, ", ") + "]")
 }
 
+// formatBytes converts an amount of bytes in a human-readable representation
+// the decimal parameter specifies if using powers of 1000 (decimal) or powers of 1024 (binary)
+func formatBytes(b uint64, decimal bool) string {
+	unit := uint64(1024)
+	format := "%.1f %ciB"
+	if decimal {
+		unit = uint64(1000)
+		format = "%.1f %cB"
+	}
+	if b < unit {
+		return fmt.Sprintf("%d B", b)
+	}
+	div, exp := unit, 0
+	for n := b / unit; n >= unit; n /= unit {
+		div *= unit
+		exp++
+	}
+	return fmt.Sprintf(format, float64(b)/float64(div), "kMGTPE"[exp])
+}
+
 // buffer takes an io.Writer and returns a wrapped version of the
 // writer that writes to both the original target as well as the returned buffer
 func buffer(w io.Writer) (io.Writer, *bytes.Buffer) {

cmd/backup/notifications.tmpl

@@ -0,0 +1,26 @@
+{{ define "title_failure" -}}
+Failure running docker-volume-backup at {{ .Stats.StartTime | formatTime }}
+{{- end }}
+
+
+{{ define "body_failure" -}}
+Running docker-volume-backup failed with error: {{ .Error }}
+
+Log output of the failed run was:
+
+{{ .Stats.LogOutput }}
+{{- end }}
+
+
+{{ define "title_success" -}}
+Success running docker-volume-backup at {{ .Stats.StartTime | formatTime }}
+{{- end }}
+
+
+{{ define "body_success" -}}
+Running docker-volume-backup succeeded.
+
+Log output was:
+
+{{ .Stats.LogOutput }}
+{{- end }}

docs/NOTIFICATION-TEMPLATES.md

@@ -0,0 +1,38 @@
+# Notification templates reference
+
+In order to customize title and body of notifications you'll have to write a [go template](https://pkg.go.dev/text/template) and mount it inside the `/etc/dockervolumebackup/notifications.d/` directory.
+
+Configuration, data about the backup run and helper functions will be passed to this template, this page documents them fully.
+
+## Data
+Here is a list of all data passed to the template:
+
+* `Config`: this object holds the configuration that has been passed to the script. The field names are the name of the recognized environment variables converted in PascalCase. (e.g. `BACKUP_STOP_CONTAINER_LABEL` becomes `BackupStopContainerLabel`)
+* `Error`: the error that made the backup fail. Only available in the `title_failure` and `body_failure` templates
+* `Stats`: objects that holds stats regarding script execution. In case of an unsuccessful run, some information may not be available.
+  * `StartTime`: time when the script started execution
+  * `EndTime`: time when the backup has completed successfully (after pruning)
+  * `TookTime`: amount of time it took for the backup to run. (equal to `EndTime - StartTime`)
+  * `LogOutput`: full log of the application
+  * `Containers`: object containing stats about the docker containers
+    * `All`: total number of containers
+    * `ToStop`: number of containers matched by the stop rule
+    * `Stopped`: number of containers successfully stopped
+    * `StopErrors`: number of containers that were unable to be stopped (equal to `ToStop - Stopped`)
+  * `BackupFile`: object containing information about the backup file
+    * `Name`: name of the backup file (e.g. `backup-2022-02-11T01-00-00.tar.gz`)
+    * `FullPath`: full path of the backup file (e.g. `/archive/backup-2022-02-11T01-00-00.tar.gz`)
+    * `Size`: size in bytes of the backup file
+  * `Storages`: object that holds stats about each storage
+    * `Local`, `S3` or `WebDAV`:
+      * `Total`: total number of backup files
+      * `Pruned`: number of backup files that were deleted due to pruning rule
+      * `PruneErrors`: number of backup files that were unable to be pruned
+
+## Functions
+
+Some formatting functions are also available:
+
+* `formatTime`: formats a time object using [RFC3339](https://datatracker.ietf.org/doc/html/rfc3339) format (e.g. `2022-02-11T01:00:00Z`)
+* `formatBytesBin`: formats an amount of bytes using powers of 1024 (e.g. `7055258` bytes will be `6.7 MiB`) 
+* `formatBytesDec`: formats an amount of bytes using powers of 1000 (e.g. `7055258` bytes will be `7.1 MB`)

go.mod

@@ -8,10 +8,11 @@ require (
 	github.com/gofrs/flock v0.8.1
 	github.com/kelseyhightower/envconfig v1.4.0
 	github.com/leekchan/timeutil v0.0.0-20150802142658-28917288c48d
-	github.com/m90/targz v0.0.0-20210904082215-2e9a4529a615
+	github.com/m90/targz v0.0.0-20220208141135-d3baeef59a97
 	github.com/minio/minio-go/v7 v7.0.16
 	github.com/otiai10/copy v1.7.0
 	github.com/sirupsen/logrus v1.8.1
+	github.com/studio-b12/gowebdav v0.0.0-20211109083228-3f8721cd4b6f
 	golang.org/x/crypto v0.0.0-20210817164053-32db794688a5
 )
 

go.sum

@@ -450,8 +450,10 @@ github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/leekchan/timeutil v0.0.0-20150802142658-28917288c48d h1:2puqoOQwi3Ai1oznMOsFIbifm6kIfJaLLyYzWD4IzTs=
 github.com/leekchan/timeutil v0.0.0-20150802142658-28917288c48d/go.mod h1:hO90vCP2x3exaSH58BIAowSKvV+0OsY21TtzuFGHON4=
 github.com/leodido/go-urn v1.2.0/go.mod h1:+8+nEpDfqqsY+g338gtMEUOtuK+4dEMhiQEgxpxOKII=
-github.com/m90/targz v0.0.0-20210904082215-2e9a4529a615 h1:rn0LO2tQEgCDOct8qnbcslTUpAIWdVlWcGkjoumhf2U=
-github.com/m90/targz v0.0.0-20210904082215-2e9a4529a615/go.mod h1:YZK3bSO/oVlk9G+v00BxgzxW2Us4p/R4ysHOBjk0fJI=
+github.com/m90/targz v0.0.0-20211229090208-2f22c2d9278e h1:Kzm2zfxS40RUGD5UVtVtOo9RT5TtGoNJnmWORtCEaxM=
+github.com/m90/targz v0.0.0-20211229090208-2f22c2d9278e/go.mod h1:YZK3bSO/oVlk9G+v00BxgzxW2Us4p/R4ysHOBjk0fJI=
+github.com/m90/targz v0.0.0-20220208141135-d3baeef59a97 h1:Uc/WzUKI/zvhkqIzk5TyaPE6AY1SD1DWGc7RV7cky4s=
+github.com/m90/targz v0.0.0-20220208141135-d3baeef59a97/go.mod h1:YZK3bSO/oVlk9G+v00BxgzxW2Us4p/R4ysHOBjk0fJI=
 github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/magiconair/properties v1.8.1/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/mailru/easyjson v0.0.0-20190403194419-1ea4449da983/go.mod h1:C1wdFJiN94OJF2b5HbByQZoLdCWB1Yqtg26g4irojpc=
@@ -659,6 +661,8 @@ github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UV
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/studio-b12/gowebdav v0.0.0-20211109083228-3f8721cd4b6f h1:L2NE7BXnSlSLoNYZ0lCwZDjdnYjCNYC71k9ClZUTFTs=
+github.com/studio-b12/gowebdav v0.0.0-20211109083228-3f8721cd4b6f/go.mod h1:bHA7t77X/QFExdeAnDzK6vKM34kEZAcE1OX4MfiwjkE=
 github.com/subosito/gotenv v1.2.0/go.mod h1:N0PQaV/YGNqwC0u51sEeR/aUtSLEXKX9iv69rRypqCw=
 github.com/syndtr/gocapability v0.0.0-20170704070218-db04d3cc01c8/go.mod h1:hkRG7XYTFWNJGYcbNJQlaLq0fg1yr4J4t/NcTQtrfww=
 github.com/syndtr/gocapability v0.0.0-20180916011248-d98352740cb2/go.mod h1:hkRG7XYTFWNJGYcbNJQlaLq0fg1yr4J4t/NcTQtrfww=

test/cli/run.sh

@@ -7,6 +7,7 @@ cd $(dirname $0)
 docker network create test_network
 docker volume create backup_data
 docker volume create app_data
+docker volume create empty_data
 
 docker run -d \
   --name minio \
@@ -31,6 +32,7 @@ sleep 10
 docker run --rm \
   --network test_network \
   -v app_data:/backup/app_data \
+  -v empty_data:/backup/empty_data \
   -v /var/run/docker.sock:/var/run/docker.sock \
   --env AWS_ACCESS_KEY_ID=test \
   --env AWS_SECRET_ACCESS_KEY=GMusLtUmILge2by+z890kQ \
@@ -44,7 +46,7 @@ docker run --rm \
 
 docker run --rm -it \
   -v backup_data:/data alpine \
-  ash -c 'tar -xvf /data/backup/test.tar.gz && test -f /backup/app_data/offen.db'
+  ash -c 'tar -xvf /data/backup/test.tar.gz && test -f /backup/app_data/offen.db && test -d /backup/empty_data'
 
 echo "[TEST:PASS] Found relevant files in untared backup."
 

test/compose/docker-compose.yml

@@ -10,13 +10,23 @@ services:
       MINIO_SECRET_KEY: GMusLtUmILge2by+z890kQ
     entrypoint: /bin/ash -c 'mkdir -p /data/backup && minio server /data'
     volumes:
-      - backup_data:/data
+      - minio_backup_data:/data
+
+  webdav:
+    image: bytemark/webdav:2.4
+    environment:
+      AUTH_TYPE: Digest
+      USERNAME: test
+      PASSWORD: test
+    volumes:
+      - webdav_backup_data:/var/lib/dav
 
   backup: &default_backup_service
     image: offen/docker-volume-backup:${TEST_VERSION}
     hostname: hostnametoken
     depends_on:
       - minio
+      - webdav
     restart: always
     environment:
       AWS_ACCESS_KEY_ID: test
@@ -32,6 +42,10 @@ services:
       BACKUP_PRUNING_LEEWAY: 5s
       BACKUP_PRUNING_PREFIX: test
       GPG_PASSPHRASE: 1234secret
+      WEBDAV_URL: http://webdav/
+      WEBDAV_PATH: /my/new/path/
+      WEBDAV_USERNAME: test
+      WEBDAV_PASSWORD: test
     volumes:
       - ./local:/archive
       - app_data:/backup/app_data:ro
@@ -45,5 +59,6 @@ services:
       - app_data:/var/opt/offen
 
 volumes:
-  backup_data:
+  minio_backup_data:
+  webdav_backup_data:
   app_data:

test/compose/run.sh

@@ -13,10 +13,13 @@ docker-compose exec offen ln -s /var/opt/offen/offen.db /var/opt/offen/db.link
 docker-compose exec backup backup
 
 docker run --rm -it \
-  -v compose_backup_data:/data alpine \
-  ash -c 'apk add gnupg && echo 1234secret | gpg -d --pinentry-mode loopback --passphrase-fd 0 --yes /data/backup/test-hostnametoken.tar.gz.gpg > /tmp/test-hostnametoken.tar.gz && tar -xf /tmp/test-hostnametoken.tar.gz -C /tmp && test -f /tmp/backup/app_data/offen.db'
+  -v compose_minio_backup_data:/minio_data \
+  -v compose_webdav_backup_data:/webdav_data alpine \
+  ash -c 'apk add gnupg && \
+          echo 1234secret | gpg -d --pinentry-mode loopback --passphrase-fd 0 --yes /minio_data/backup/test-hostnametoken.tar.gz.gpg > /tmp/test-hostnametoken.tar.gz && tar -xf /tmp/test-hostnametoken.tar.gz -C /tmp && test -f /tmp/backup/app_data/offen.db && \
+          echo 1234secret | gpg -d --pinentry-mode loopback --passphrase-fd 0 --yes /webdav_data/data/my/new/path/test-hostnametoken.tar.gz.gpg > /tmp/test-hostnametoken.tar.gz && tar -xf /tmp/test-hostnametoken.tar.gz -C /tmp && test -f /tmp/backup/app_data/offen.db'
 
-echo "[TEST:PASS] Found relevant files in untared remote backup."
+echo "[TEST:PASS] Found relevant files in untared remote backups."
 
 test -L ./local/test-hostnametoken.latest.tar.gz.gpg
 echo 1234secret | gpg -d --yes --passphrase-fd 0 ./local/test-hostnametoken.tar.gz.gpg > ./local/decrypted.tar.gz
@@ -26,7 +29,7 @@ test -L /tmp/backup/app_data/db.link
 
 echo "[TEST:PASS] Found relevant files in untared local backup."
 
-if [ "$(docker-compose ps -q | wc -l)" != "3" ]; then
+if [ "$(docker-compose ps -q | wc -l)" != "4" ]; then
   echo "[TEST:FAIL] Expected all containers to be running post backup, instead seen:"
   docker-compose ps
   exit 1
@@ -43,8 +46,10 @@ sleep 5
 docker-compose exec backup backup
 
 docker run --rm -it \
-  -v compose_backup_data:/data alpine \
-  ash -c '[ $(find /data/backup/ -type f | wc -l) = "1" ]'
+  -v compose_minio_backup_data:/minio_data \
+  -v compose_webdav_backup_data:/webdav_data alpine \
+  ash -c '[ $(find /minio_data/backup/ -type f | wc -l) = "1" ] && \
+          [ $(find /webdav_data/data/my/new/path/ -type f | wc -l) = "1" ]'
 
 echo "[TEST:PASS] Remote backups have not been deleted."
 

test/swarm/run.sh

@@ -23,6 +23,7 @@ docker run --rm -it \
 
 echo "[TEST:PASS] Found relevant files in untared backup."
 
+sleep 5
 if [ "$(docker ps -q | wc -l)" != "5" ]; then
   echo "[TEST:FAIL] Expected all containers to be running post backup, instead seen:"
   docker ps -a