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>

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."