Support Nextcloud / WebDav (#48)

* add studio-b12/gowebdav to be able to upload to webdav server

* make sure all env variables are present for webdav upload

* implement file upload to WebDav server

directory defaults to the base directory

* docs: add the new feature to the documentation

* if no WebDav env variable are given throw no error

* docs: use more elegant english :D

Co-authored-by: Frederik Ring <frederik.ring@gmail.com>

* docs: use official spelling of "WebDAV"

* perf: golang likes to return early instead of having an else block

* use WEBDAV_PATH instead of WEBDAV_DIRECTORY

* use split_words for more convenience

like shown here: https://github.com/kelseyhightower/envconfig#struct-tag-support

* simplify

* feat: add pruning of files in WebDAV remote

Based on / Inspired by the minio/S3 implementation of pruning remote files.

* remove logging from the development

* test: first try implementing tests

Sandly I have to use the remote pipeline -- local wont work for me.

* test: adapt used volume names

* test: specify image only once!

* test: minio AND webdav data should be present

* test: backups on WebDAV remote are laying in the root directory

* test: the webdav server stores date in /var/lib/dav

* trying with data subfolder

* test: 1 container was added so the number raised from 3 to 4

* webdav  subfolder is "data" not "backup"

* fix: password AND username must be defined

not password OR username

* improve logging

* feat: if the given path on the server isnt preset it will be created

* test: add creation of new folder for webdav to tests

Co-authored-by: Frederik Ring <frederik.ring@gmail.com>

README.md

@@ -7,7 +7,7 @@
 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 -->
 
@@ -28,6 +28,7 @@ It handles __recurring or one-off backups of Docker volumes__ to a __local direc
 - [Recipes](#recipes)
   - [Backing up to AWS S3](#backing-up-to-aws-s3)
   - [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)
@@ -189,6 +190,24 @@ You can populate below template according to your requirements and use it as you
 
 # AWS_ENDPOINT_INSECURE="true"
 
+# In addition, 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`
@@ -530,6 +549,28 @@ 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

@@ -9,6 +9,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"io/fs"
 	"os"
 	"path"
 	"path/filepath"
@@ -32,6 +33,7 @@ import (
 	"github.com/otiai10/copy"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/crypto/openpgp"
+	"github.com/studio-b12/gowebdav"
 )
 
 func main() {
@@ -88,6 +90,7 @@ func main() {
 type script struct {
 	cli           *client.Client
 	mc            *minio.Client
+	webdavClient  *gowebdav.Client
 	logger        *logrus.Logger
 	sender        *router.ServiceRouter
 	hooks         []hook
@@ -127,6 +130,10 @@ 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"
@@ -209,6 +216,17 @@ func newScript() (*script, error) {
 		s.mc = mc
 	}
 
+	// WebDAV check for env variables
+	// WebDAV instanciate client
+	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 != "" {
 		emailURL := fmt.Sprintf(
 			"smtp://%s:%s@%s:%d/?from=%s&to=%s",
@@ -517,6 +535,21 @@ func (s *script) copyBackup() error {
 		s.logger.Infof("Uploaded a copy of backup `%s` to bucket `%s`.", s.file, s.c.AwsS3BucketName)
 	}
 
+	// WebDAV file upload
+	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)
@@ -551,6 +584,7 @@ func (s *script) pruneOldBackups() error {
 
 	deadline := time.Now().AddDate(0, 0, -int(s.c.BackupRetentionDays))
 
+	// Prune minio/S3 backups
 	if s.mc != nil {
 		candidates := s.mc.ListObjects(context.Background(), s.c.AwsS3BucketName, minio.ListObjectsOptions{
 			WithMetadata: true,
@@ -612,6 +646,38 @@ 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)
+			}
+		}
+
+		if len(matches) != 0 && len(matches) != lenCandidates {
+			for _, match := range matches {
+				if err := s.webdavClient.Remove(filepath.Join(s.c.WebdavPath, match.Name())); err != nil {
+					return fmt.Errorf("pruneOldBackups: error removing a file from remote storage: %w", err)
+				}
+				s.logger.Infof("Pruned %s from WebDAV: %s", match.Name(), filepath.Join(s.c.WebdavUrl, s.c.WebdavPath))
+			}
+			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.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,

go.mod

@@ -45,6 +45,7 @@ require (
 	github.com/opencontainers/image-spec v1.0.1 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/rs/xid v1.3.0 // indirect
+	github.com/studio-b12/gowebdav v0.0.0-20211109083228-3f8721cd4b6f // indirect
 	golang.org/x/net v0.0.0-20210226172049-e18ecbb05110 // indirect
 	golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 // indirect
 	golang.org/x/text v0.3.6 // indirect

go.sum

@@ -659,6 +659,8 @@ 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/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."