Add remote borg backup support (#4804)

Signed-off-by: Tim Diels <tim@diels.me>
Signed-off-by: Simon L. <szaimen@e.mail.de>
Co-authored-by: Simon L. <szaimen@e.mail.de>

Containers/borgbackup/Dockerfile

@@ -11,11 +11,13 @@ RUN set -ex; \
         rsync \
         fuse \
         py3-llfuse \
-        jq
+        jq \
+        openssh-client
 
 VOLUME /root
 
 COPY --chmod=770 *.sh /
+COPY borg_excludes /
 
 ENTRYPOINT ["/start.sh"]
 # hadolint ignore=DL3002

Containers/borgbackup/backupscript.sh

@@ -34,19 +34,23 @@ for volume in "${DEFAULT_VOLUMES[@]}"; do
 done
 
 # Check if target is mountpoint
-if ! mountpoint -q /mnt/borgbackup; then
-    echo "/mnt/borgbackup is not a mountpoint which is not allowed."
+if [ -z "$BORG_REMOTE_REPO" ] && ! mountpoint -q "$MOUNT_DIR"; then
+    echo "$MOUNT_DIR is not a mountpoint which is not allowed."
     exit 1
 fi
 
-# Check if target is empty
-if [ "$BORG_MODE" != backup ] && [ "$BORG_MODE" != test ] && ! [ -f "$BORG_BACKUP_DIRECTORY/config" ]; then
-    echo "The repository is empty. Cannot perform check or restore."
+# Check if repo is uninitialized
+if [ "$BORG_MODE" != backup ] && [ "$BORG_MODE" != test ] && ! borg info > /dev/null; then
+    if [ -n "$BORG_REMOTE_REPO" ]; then
+        echo "The repository is uninitialized or cannot connect to remote. Cannot perform check or restore."
+    else
+        echo "The repository is uninitialized. Cannot perform check or restore."
+    fi
     exit 1
 fi
 
 # Do not continue if this file exists (needed for simple external blocking)
-if [ -f "$BORG_BACKUP_DIRECTORY/aio-lockfile" ]; then
+if [ -z "$BORG_REMOTE_REPO" ] && [ -f "$BORG_BACKUP_DIRECTORY/aio-lockfile" ]; then
     echo "Not continuing because aio-lockfile exists – it seems like a script is externally running which is locking the backup archive."
     echo "If this should not be the case, you can fix this by deleting the 'aio-lockfile' file from the backup archive directory."
     exit 1
@@ -57,6 +61,13 @@ if [ "$BORG_MODE" = backup ] || [ "$BORG_MODE" = restore ]; then
     touch "/nextcloud_aio_volumes/nextcloud_aio_database_dump/backup-is-running"
 fi
 
+if [ -n "$BORG_REMOTE_REPO" ] && ! [ -f "$BORGBACKUP_KEY" ]; then
+    echo "First run, creating borg ssh key"
+    ssh-keygen  -f "$BORGBACKUP_KEY" -N ""
+    echo "You should configure the remote to accept this public key"
+fi
+echo "Your public ssh key for borgbackup is: $(cat "$BORGBACKUP_KEY.pub")"
+
 # Do the backup
 if [ "$BORG_MODE" = backup ]; then
 
@@ -100,15 +111,22 @@ if [ "$BORG_MODE" = backup ]; then
         exit 1
     fi
 
-    # Create backup folder
-    mkdir -p "$BORG_BACKUP_DIRECTORY"
+    if [ -z "$BORG_REMOTE_REPO" ]; then
+        # Create backup folder
+        mkdir -p "$BORG_BACKUP_DIRECTORY"
+    fi
 
-    # Initialize the repository if the target is empty
-    if ! [ -f "$BORG_BACKUP_DIRECTORY/config" ]; then
+    # Initialize the repository if can't get info from target
+    if ! borg info > /dev/null; then
         # Don't initialize if already initialized
         if [ -f "/nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/borg.config" ]; then
-            echo "No borg config file was found in the targeted directory."
-            echo "This might happen if the targeted directory is located on an external drive and the drive not connected anymore. You should check this."
+            if [ -n "$BORG_REMOTE_REPO" ]; then
+                echo "Borg could not get info from the remote repo."
+                echo "This might be a failure to connect to the remote server. See the above borg info output for details."
+            else
+                echo "Borg could not get info from the targeted directory."
+                echo "This might happen if the targeted directory is located on an external drive and the drive not connected anymore. You should check this."
+            fi
             echo "If you instead want to initialize a new backup repository, you may delete the 'borg.config' file that is stored in the mastercontainer volume manually, which will allow you to initialize a new borg repository in the chosen directory:"
             echo "sudo docker exec nextcloud-aio-mastercontainer rm /mnt/docker-aio-config/data/borg.config"
             exit 1
@@ -116,28 +134,44 @@ if [ "$BORG_MODE" = backup ]; then
 
         echo "Initializing repository..."
         NEW_REPOSITORY=1
-        if ! borg init --debug --encryption=repokey-blake2 "$BORG_BACKUP_DIRECTORY"; then
+        if ! borg init --debug --encryption=repokey-blake2; then
             echo "Could not initialize borg repository."
-            rm -f "$BORG_BACKUP_DIRECTORY/config"
+            if [ -z "$BORG_REMOTE_REPO" ]; then
+                # Originally we checked for presence of the config file instead of calling `borg info`. Likely `borg info`
+                # will error on a partially initialized repo, so this line is probably no longer necessary
+                rm -f "$BORG_BACKUP_DIRECTORY/config"
+            fi
             exit 1
         fi
-        borg config "$BORG_BACKUP_DIRECTORY" additional_free_space 2G
 
-        # Fix too large Borg cache
-        # https://borgbackup.readthedocs.io/en/stable/faq.html#the-borg-cache-eats-way-too-much-disk-space-what-can-i-do
-        BORG_ID="$(borg config "$BORG_BACKUP_DIRECTORY" id)"
-        rm -r "/root/.cache/borg/$BORG_ID/chunks.archive.d"
-        touch "/root/.cache/borg/$BORG_ID/chunks.archive.d"
+        if [ -z "$BORG_REMOTE_REPO" ]; then
+            # borg config only works for local repos; it's up to the remote to ensure the disk isn't full
+            borg config :: additional_free_space 2G
 
-        # Make a backup from the borg config file
-        if ! [ -f "$BORG_BACKUP_DIRECTORY/config" ]; then
-            echo "The borg config file wasn't created. Something is wrong."
+            # Fix too large Borg cache
+            # https://borgbackup.readthedocs.io/en/stable/faq.html#the-borg-cache-eats-way-too-much-disk-space-what-can-i-do
+            BORG_ID="$(borg config :: id)"
+            rm -r "/root/.cache/borg/$BORG_ID/chunks.archive.d"
+            touch "/root/.cache/borg/$BORG_ID/chunks.archive.d"
+        fi
+
+        if ! borg info > /dev/null; then
+            echo "Borg can't get info from the repo it created. Something is wrong."
             exit 1
         fi
+
         rm -f "/nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/borg.config"
-        if ! cp "$BORG_BACKUP_DIRECTORY/config" "/nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/borg.config"; then
-            echo "Could not copy config file to second place. Cannot perform backup."
-            exit 1
+        if [ -n "$BORG_REMOTE_REPO" ]; then
+            # `borg config` does not support remote repos so instead create a dummy file and rely on the remote to avoid
+            # corruption of the config file (which contains the encryption key). We don't actually use the contents of
+            # this file anywhere, so a touch is all we need so we remember we already initialized the repo.
+            touch "/nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/borg.config"
+        else
+            # Make a backup from the borg config file
+            if ! cp "$BORG_BACKUP_DIRECTORY/config" "/nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/borg.config"; then
+                echo "Could not copy config file to second place. Cannot perform backup."
+                exit 1
+            fi
         fi
 
         echo "Repository successfully initialized."
@@ -167,9 +201,9 @@ if [ "$BORG_MODE" = backup ]; then
     # Create the backup
     echo "Starting the backup..."
     get_start_time
-    if ! borg create "${BORG_OPTS[@]}" "${BORG_EXCLUDE[@]}" "$BORG_BACKUP_DIRECTORY::$CURRENT_DATE-nextcloud-aio" "/nextcloud_aio_volumes/"; then
+    if ! borg create "${BORG_OPTS[@]}" "${BORG_EXCLUDE[@]}" "::$CURRENT_DATE-nextcloud-aio" "/nextcloud_aio_volumes/" --exclude-from /borg_excludes; then
         echo "Deleting the failed backup archive..."
-        borg delete --stats "$BORG_BACKUP_DIRECTORY::$CURRENT_DATE-nextcloud-aio"
+        borg delete --stats "::$CURRENT_DATE-nextcloud-aio"
         echo "Backup failed!"
         echo "You might want to check the backup integrity via the AIO interface."
         if [ "$NEW_REPOSITORY" = 1 ]; then
@@ -188,14 +222,14 @@ if [ "$BORG_MODE" = backup ]; then
 
     # Prune archives
     echo "Pruning the archives..."
-    if ! borg prune --stats --glob-archives '*_*-nextcloud-aio' "${BORG_PRUNE_OPTS[@]}" "$BORG_BACKUP_DIRECTORY"; then
+    if ! borg prune --stats --glob-archives '*_*-nextcloud-aio' "${BORG_PRUNE_OPTS[@]}"; then
         echo "Failed to prune archives!"
         exit 1
     fi
 
     # Compact archives
     echo "Compacting the archives..."
-    if ! borg compact "$BORG_BACKUP_DIRECTORY"; then
+    if ! borg compact; then
         echo "Failed to compact archives!"
         exit 1
     fi
@@ -212,19 +246,19 @@ if [ "$BORG_MODE" = backup ]; then
                 fi
             done
             echo "Starting the backup for additional volumes..."
-            if ! borg create "${BORG_OPTS[@]}" "$BORG_BACKUP_DIRECTORY::$CURRENT_DATE-additional-docker-volumes" "/docker_volumes/"; then
+            if ! borg create "${BORG_OPTS[@]}" "::$CURRENT_DATE-additional-docker-volumes" "/docker_volumes/"; then
                 echo "Deleting the failed backup archive..."
-                borg delete --stats "$BORG_BACKUP_DIRECTORY::$CURRENT_DATE-additional-docker-volumes"
+                borg delete --stats "::$CURRENT_DATE-additional-docker-volumes"
                 echo "Backup of additional docker-volumes failed!"
                 exit 1
             fi
             echo "Pruning additional volumes..."
-            if ! borg prune --stats --glob-archives '*_*-additional-docker-volumes' "${BORG_PRUNE_OPTS[@]}" "$BORG_BACKUP_DIRECTORY"; then
+            if ! borg prune --stats --glob-archives '*_*-additional-docker-volumes' "${BORG_PRUNE_OPTS[@]}"; then
                 echo "Failed to prune additional docker-volumes archives!"
                 exit 1
             fi
             echo "Compacting additional volumes..."
-            if ! borg compact "$BORG_BACKUP_DIRECTORY"; then
+            if ! borg compact; then
                 echo "Failed to compact additional docker-volume archives!"
                 exit 1
             fi
@@ -242,19 +276,19 @@ if [ "$BORG_MODE" = backup ]; then
                 EXCLUDE_DIRS+=(--exclude "/host_mounts/$directory/")
             done
             echo "Starting the backup for additional host mounts..."
-            if ! borg create "${BORG_OPTS[@]}" "${EXCLUDE_DIRS[@]}" "$BORG_BACKUP_DIRECTORY::$CURRENT_DATE-additional-host-mounts" "/host_mounts/"; then
+            if ! borg create "${BORG_OPTS[@]}" "${EXCLUDE_DIRS[@]}" "::$CURRENT_DATE-additional-host-mounts" "/host_mounts/"; then
                 echo "Deleting the failed backup archive..."
-                borg delete --stats "$BORG_BACKUP_DIRECTORY::$CURRENT_DATE-additional-host-mounts"
+                borg delete --stats "::$CURRENT_DATE-additional-host-mounts"
                 echo "Backup of additional host-mounts failed!"
                 exit 1
             fi
             echo "Pruning additional host mounts..."
-            if ! borg prune --stats --glob-archives '*_*-additional-host-mounts' "${BORG_PRUNE_OPTS[@]}" "$BORG_BACKUP_DIRECTORY"; then
+            if ! borg prune --stats --glob-archives '*_*-additional-host-mounts' "${BORG_PRUNE_OPTS[@]}"; then
                 echo "Failed to prune additional host-mount archives!"
                 exit 1
             fi
             echo "Compacting additional host mounts..."
-            if ! borg compact "$BORG_BACKUP_DIRECTORY"; then
+            if ! borg compact; then
                 echo "Failed to compact additional host-mount archives!"
                 exit 1
             fi
@@ -276,18 +310,13 @@ fi
 if [ "$BORG_MODE" = restore ]; then
     get_start_time
 
-    # Perform the restore
+    # Pick archive to restore
     if [ -n "$SELECTED_RESTORE_TIME" ]; then
-        SELECTED_ARCHIVE="$(borg list "$BORG_BACKUP_DIRECTORY" | grep "nextcloud-aio" | grep "$SELECTED_RESTORE_TIME" | awk -F " " '{print $1}' | head -1)"
+        SELECTED_ARCHIVE="$(borg list | grep "nextcloud-aio" | grep "$SELECTED_RESTORE_TIME" | awk -F " " '{print $1}' | head -1)"
     else
-        SELECTED_ARCHIVE="$(borg list "$BORG_BACKUP_DIRECTORY" | grep "nextcloud-aio" | awk -F " " '{print $1}' | sort -r | head -1)"
+        SELECTED_ARCHIVE="$(borg list | grep "nextcloud-aio" | awk -F " " '{print $1}' | sort -r | head -1)"
     fi
     echo "Restoring '$SELECTED_ARCHIVE'..."
-    mkdir -p /tmp/borg
-    if ! borg mount "$BORG_BACKUP_DIRECTORY::$SELECTED_ARCHIVE" /tmp/borg; then
-        echo "Could not mount the backup!"
-        exit 1
-    fi
 
     # Save Additional Backup dirs
     if [ -f "/nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/additional_backup_directories" ]; then
@@ -299,27 +328,12 @@ if [ "$BORG_MODE" = restore ]; then
         DAILY_BACKUPTIME="$(cat /nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/daily_backup_time)"
     fi
 
-    # Restore everything except the configuration file
-    if ! rsync --stats --archive --human-readable -vv --delete \
-    --exclude "nextcloud_aio_apache/caddy/**" \
-    --exclude "nextcloud_aio_mastercontainer/caddy/**" \
-    --exclude "nextcloud_aio_nextcloud/data/nextcloud.log*" \
-    --exclude "nextcloud_aio_nextcloud/data/audit.log" \
-    --exclude "nextcloud_aio_mastercontainer/certs/**" \
-    --exclude "nextcloud_aio_mastercontainer/data/configuration.json" \
-    --exclude "nextcloud_aio_mastercontainer/data/daily_backup_running" \
-    --exclude "nextcloud_aio_mastercontainer/data/session_date_file" \
-    --exclude "nextcloud_aio_mastercontainer/session/**" \
-    /tmp/borg/nextcloud_aio_volumes/ /nextcloud_aio_volumes/; then
-        RESTORE_FAILED=1
-        echo "Something failed while restoring from backup."
-    fi
-
     # Save current aio password
     AIO_PASSWORD="$(jq '.password' /nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json)"
 
-    # Save current path
+    # Save current backup location vars
     BORG_LOCATION="$(jq '.borg_backup_host_location' /nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json)"
+    REMOTE_REPO="$(jq '.borg_remote_repo' /nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json)"
 
     # Save current nextcloud datadir
     if grep -q '"nextcloud_datadir":' /nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json; then
@@ -328,21 +342,111 @@ if [ "$BORG_MODE" = restore ]; then
         NEXTCLOUD_DATADIR='""'
     fi
 
-    # Restore the configuration file
-    if ! rsync --archive --human-readable -vv \
-    /tmp/borg/nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json \
-    /nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json; then
-        RESTORE_FAILED=1
-        echo "Something failed while restoring the configuration.json."
+    if [ -z "$BORG_REMOTE_REPO" ]; then
+        mkdir -p /tmp/borg
+        if ! borg mount "::$SELECTED_ARCHIVE" /tmp/borg; then
+            echo "Could not mount the backup!"
+            exit 1
+        fi
+
+        # Restore everything except the configuration file
+        #
+        # These exclude patterns need to be kept in sync with the borg_excludes file and the find excludes in this file,
+        # which use a different syntax (patterns appear in 3 places in total)
+        if ! rsync --stats --archive --human-readable -vv --delete \
+        --exclude "nextcloud_aio_apache/caddy/**" \
+        --exclude "nextcloud_aio_mastercontainer/caddy/**" \
+        --exclude "nextcloud_aio_nextcloud/data/nextcloud.log*" \
+        --exclude "nextcloud_aio_nextcloud/data/audit.log" \
+        --exclude "nextcloud_aio_mastercontainer/certs/**" \
+        --exclude "nextcloud_aio_mastercontainer/data/configuration.json" \
+        --exclude "nextcloud_aio_mastercontainer/data/daily_backup_running" \
+        --exclude "nextcloud_aio_mastercontainer/data/session_date_file" \
+        --exclude "nextcloud_aio_mastercontainer/session/**" \
+        /tmp/borg/nextcloud_aio_volumes/ /nextcloud_aio_volumes/; then
+            RESTORE_FAILED=1
+            echo "Something failed while restoring from backup."
+        fi
+
+        # Restore the configuration file
+        if ! rsync --archive --human-readable -vv \
+                /tmp/borg/nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json \
+                /nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json; then
+            RESTORE_FAILED=1
+            echo "Something failed while restoring the configuration.json."
+        fi
+
+        if ! umount /tmp/borg; then
+            echo "Failed to unmount the borg archive but should still be able to restore successfully"
+        fi
+    else
+        # Restore nearly everything
+        #
+        # borg mount is really slow for remote repos (did not check whether it's slow for local repos too),
+        # using extract to /tmp would require temporarily storing a second copy of the data.
+        # So instead extract directly on top of the destination with exclude patterns for the config, but
+        # then we do still need to delete local files which are not present in the archive.
+        #
+        # Older backups may still contain files we've since excluded, so we have to exclude on extract as well.
+        cd /  # borg extract has no destination arg and extracts to CWD
+        if ! borg extract "::$SELECTED_ARCHIVE" --progress --exclude-from /borg_excludes --pattern '+nextcloud_aio_volumes/**'
+        then
+            RESTORE_FAILED=1
+            echo "Failed to extract backup archive."
+        else
+            # Delete files/dirs present locally, but not in the backup archive, excluding conf files
+            # https://unix.stackexchange.com/a/759341
+            # This comm does not support -z, but I doubt any file names would have \n in them
+            echo "Deleting local files which do not exist in the backup"
+            # These find patterns need to be kept in sync with the borg_excludes file and the rsync excludes in this
+            # file, which use a different syntax (patterns appear in 3 places in total)
+            if ! find nextcloud_aio_volumes \
+                    -not \( \
+                        -path nextcloud_aio_volumes/nextcloud_aio_apache/caddy \
+                        -o -path "nextcloud_aio_volumes/nextcloud_aio_apache/caddy/*" \
+                        -o -path nextcloud_aio_volumes/nextcloud_aio_mastercontainer/caddy \
+                        -o -path "nextcloud_aio_volumes/nextcloud_aio_mastercontainer/caddy/*" \
+                        -o -path nextcloud_aio_volumes/nextcloud_aio_mastercontainer/certs \
+                        -o -path "nextcloud_aio_volumes/nextcloud_aio_mastercontainer/certs/*" \
+                        -o -path nextcloud_aio_volumes/nextcloud_aio_mastercontainer/session \
+                        -o -path "nextcloud_aio_volumes/nextcloud_aio_mastercontainer/session/*" \
+                        -o -path "nextcloud_aio_volumes/nextcloud_aio_nextcloud/data/nextcloud.log*" \
+                        -o -path nextcloud_aio_volumes/nextcloud_aio_nextcloud/data/audit.log \
+                        -o -path nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/daily_backup_running \
+                        -o -path nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/session_date_file \
+                        -o -path "nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/id_borg*" \
+                    \) \
+                    | LC_ALL=C sort \
+                    | LC_ALL=C comm -23 - \
+                        <(borg list "::$SELECTED_ARCHIVE" --short --exclude-from /borg_excludes  --pattern '+nextcloud_aio_volumes/**' | LC_ALL=C sort) \
+                    > /tmp/local_files_not_in_backup
+            then
+                RESTORE_FAILED=1
+                echo "Failed to delete local files not in backup archive."
+            else
+                # More robust than e.g. xargs as I got a ~"args line too long" error while testing that, but it's slower
+                # https://stackoverflow.com/a/21848934
+                while IFS= read -r file
+                do rm -vrf -- "$file" || DELETE_FAILED=1
+                done < /tmp/local_files_not_in_backup
+
+                if [ "$DELETE_FAILED" = 1 ]; then
+                    RESTORE_FAILED=1
+                    echo "Failed to delete (some) local files not in backup archive."
+                fi
+            fi
+        fi
     fi
 
     # Set backup-mode to restore since it was a restore
     CONTENTS="$(jq '."backup-mode" = "restore"' /nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json)"
     echo -E "${CONTENTS}" > /nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json
 
-    # Reset the backup path to the currently used one
+    # Reset the backup location vars to the currently used one
     CONTENTS="$(jq ".borg_backup_host_location = $BORG_LOCATION" /nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json)"
     echo -E "${CONTENTS}" > /nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json
+    CONTENTS="$(jq ".borg_remote_repo = $REMOTE_REPO" /nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json)"
+    echo -E "${CONTENTS}" > /nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json
 
     # Reset the AIO password to the currently used one
     CONTENTS="$(jq ".password = $AIO_PASSWORD" /nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/configuration.json)"
@@ -366,8 +470,6 @@ if [ "$BORG_MODE" = restore ]; then
         chmod 770 "/nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/daily_backup_time"
     fi
 
-    umount /tmp/borg
-
     if [ "$RESTORE_FAILED" = 1 ]; then
         exit 1
     fi
@@ -394,7 +496,7 @@ if [ "$BORG_MODE" = check ]; then
     echo "Checking the backup integrity..."
 
     # Perform the check
-    if ! borg check -v --verify-data "$BORG_BACKUP_DIRECTORY"; then
+    if ! borg check -v --verify-data; then
         echo "Some errors were found while checking the backup integrity!"
         echo "Check the AIO interface for advices on how to proceed now!"
         exit 1
@@ -412,7 +514,7 @@ if [ "$BORG_MODE" = "check-repair" ]; then
     echo "Checking the backup integrity and repairing it..."
 
     # Perform the check-repair
-    if ! echo YES | borg check -v --repair "$BORG_BACKUP_DIRECTORY"; then
+    if ! echo YES | borg check -v --repair; then
         echo "Some errors were found while checking and repairing the backup integrity!"
         exit 1
     fi
@@ -425,19 +527,29 @@ fi
 
 # Do the backup test
 if [ "$BORG_MODE" = test ]; then
-    if ! [ -d "$BORG_BACKUP_DIRECTORY" ]; then
-        echo "No 'borg' directory in the given backup directory found!"
-        echo "Only the files/folders below have been found in the given directory."
-        ls -a "$MOUNT_DIR"
-        echo "Please adjust the directory so that the borg archive is positioned in a folder named 'borg' inside the given directory!"
-        exit 1
-    elif ! [ -f "$BORG_BACKUP_DIRECTORY/config" ]; then
-        echo "A 'borg' directory was found but could not find the borg archive."
-        echo "Only the files/folders below have been found in the borg directory."
-        ls -a "$BORG_BACKUP_DIRECTORY"
-        echo "The archive and most importantly the config file must be positioned directly in the 'borg' subfolder."
-        exit 1
-    elif ! borg list "$BORG_BACKUP_DIRECTORY"; then
+    if [ -n "$BORG_REMOTE_REPO" ]; then
+        if ! borg info > /dev/null; then
+            echo "Borg could not get info from the remote repo."
+            echo "See the above borg info output for details."
+            exit 1
+        fi
+    else
+        if ! [ -d "$BORG_BACKUP_DIRECTORY" ]; then
+            echo "No 'borg' directory in the given backup directory found!"
+            echo "Only the files/folders below have been found in the given directory."
+            ls -a "$MOUNT_DIR"
+            echo "Please adjust the directory so that the borg archive is positioned in a folder named 'borg' inside the given directory!"
+            exit 1
+        elif ! [ -f "$BORG_BACKUP_DIRECTORY/config" ]; then
+            echo "A 'borg' directory was found but could not find the borg archive."
+            echo "Only the files/folders below have been found in the borg directory."
+            ls -a "$BORG_BACKUP_DIRECTORY"
+            echo "The archive and most importantly the config file must be positioned directly in the 'borg' subfolder."
+            exit 1
+        fi
+    fi
+
+    if ! borg list; then
         echo "The entered path seems to be valid but could not open the backup archive."
         echo "Most likely the entered password was wrong so please adjust it accordingly!"
         exit 1

Containers/borgbackup/borg_excludes

@@ -0,0 +1,11 @@
+# These patterns need to be kept in sync with rsync and find excludes in backupscript.sh,
+# which use a different syntax (patterns appear in 3 places in total)
+nextcloud_aio_volumes/nextcloud_aio_apache/caddy/
+nextcloud_aio_volumes/nextcloud_aio_mastercontainer/caddy/
+nextcloud_aio_volumes/nextcloud_aio_nextcloud/data/nextcloud.log*
+nextcloud_aio_volumes/nextcloud_aio_nextcloud/data/audit.log
+nextcloud_aio_volumes/nextcloud_aio_mastercontainer/certs/
+nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/daily_backup_running
+nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/session_date_file
+nextcloud_aio_volumes/nextcloud_aio_mastercontainer/session/
+nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/id_borg*

Containers/borgbackup/start.sh

@@ -2,7 +2,7 @@
 
 # Variables
 export MOUNT_DIR="/mnt/borgbackup"
-export BORG_BACKUP_DIRECTORY="$MOUNT_DIR/borg"
+export BORG_BACKUP_DIRECTORY="$MOUNT_DIR/borg"  # necessary even when remote to store the aio-lockfile
 
 # Validate BORG_PASSWORD
 if [ -z "$BORG_PASSWORD" ] && [ -z "$BACKUP_RESTORE_PASSWORD" ]; then
@@ -18,6 +18,18 @@ else
 fi
 export BORG_UNKNOWN_UNENCRYPTED_REPO_ACCESS_IS_OK=yes
 export BORG_RELOCATED_REPO_ACCESS_IS_OK=yes
+if [ -n "$BORG_REMOTE_REPO" ]; then
+    export BORG_REPO="$BORG_REMOTE_REPO"
+
+    # Location to create the borg ssh pub/priv key
+    export BORGBACKUP_KEY="/nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/id_borg"
+
+    # Accept any host key the first time connecting to the remote. Strictly speaking should be provided by user but you'd
+    # have to be very unlucky to get MitM'ed on your first connection.
+    export BORG_RSH="ssh -o StrictHostKeyChecking=accept-new -i $BORGBACKUP_KEY"
+else
+    export BORG_REPO="$BORG_BACKUP_DIRECTORY"
+fi
 
 # Validate BORG_MODE
 if [ "$BORG_MODE" != backup ] && [ "$BORG_MODE" != restore ] && [ "$BORG_MODE" != check ] && [ "$BORG_MODE" != "check-repair" ] && [ "$BORG_MODE" != test ]; then
@@ -36,8 +48,8 @@ fi
 rm -f "/nextcloud_aio_volumes/nextcloud_aio_database_dump/backup-is-running"
 
 # Get a list of all available borg archives
-if borg list "$BORG_BACKUP_DIRECTORY" &>/dev/null; then
-    borg list "$BORG_BACKUP_DIRECTORY" | grep "nextcloud-aio" | awk -F " " '{print $1","$3,$4}' > "/nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/backup_archives.list"
+if borg list &>/dev/null; then
+    borg list | grep "nextcloud-aio" | awk -F " " '{print $1","$3,$4}' > "/nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/backup_archives.list"
 else
     echo "" > "/nextcloud_aio_volumes/nextcloud_aio_mastercontainer/data/backup_archives.list"
 fi

php/containers.json

@@ -473,6 +473,7 @@
       "image": "nextcloud/aio-borgbackup",
       "init": true,
       "environment": [
+        "BORG_REMOTE_REPO=%BORGBACKUP_REMOTE_REPO%",
         "BORG_PASSWORD=%BORGBACKUP_PASSWORD%",
         "BORG_MODE=%BORGBACKUP_MODE%",
         "SELECTED_RESTORE_TIME=%SELECTED_RESTORE_TIME%",

php/public/index.php

@@ -86,6 +86,8 @@ $app->get('/containers', function (Request $request, Response $response, array $
         'domain' => $configurationManager->GetDomain(),
         'apache_port' => $configurationManager->GetApachePort(),
         'borg_backup_host_location' => $configurationManager->GetBorgBackupHostLocation(),
+        'borg_remote_repo' => $configurationManager->GetBorgRemoteRepo(),
+        'borg_public_key' => $configurationManager->GetBorgPublicKey(),
         'nextcloud_password' => $configurationManager->GetAndGenerateSecret('NEXTCLOUD_PASSWORD'),
         'containers' => (new \AIO\ContainerDefinitionFetcher($container->get(\AIO\Data\ConfigurationManager::class), $container))->FetchDefinition(),
         'borgbackup_password' => $configurationManager->GetAndGenerateSecret('BORGBACKUP_PASSWORD'),

php/src/Controller/ConfigurationController.php

@@ -28,15 +28,17 @@ readonly class ConfigurationController {
                 $this->configurationManager->ChangeMasterPassword($currentMasterPassword, $newMasterPassword);
             }
 
-            if (isset($request->getParsedBody()['borg_backup_host_location'])) {
+            if (isset($request->getParsedBody()['borg_backup_host_location']) || isset($request->getParsedBody()['borg_remote_repo'])) {
                 $location = $request->getParsedBody()['borg_backup_host_location'] ?? '';
-                $this->configurationManager->SetBorgBackupHostLocation($location);
+                $borgRemoteRepo = $request->getParsedBody()['borg_remote_repo'] ?? '';
+                $this->configurationManager->SetBorgLocationVars($location, $borgRemoteRepo);
             }
 
-            if (isset($request->getParsedBody()['borg_restore_host_location']) || isset($request->getParsedBody()['borg_restore_password'])) {
+            if (isset($request->getParsedBody()['borg_restore_host_location']) || isset($request->getParsedBody()['borg_restore_remote_repo']) || isset($request->getParsedBody()['borg_restore_password'])) {
                 $restoreLocation = $request->getParsedBody()['borg_restore_host_location'] ?? '';
+                $borgRemoteRepo = $request->getParsedBody()['borg_restore_remote_repo'] ?? '';
                 $borgPassword = $request->getParsedBody()['borg_restore_password'] ?? '';
-                $this->configurationManager->SetBorgRestoreHostLocationAndPassword($restoreLocation, $borgPassword);
+                $this->configurationManager->SetBorgRestoreLocationVarsAndPassword($restoreLocation, $borgRemoteRepo, $borgPassword);
             }
 
             if (isset($request->getParsedBody()['daily_backup_time'])) {
@@ -132,8 +134,8 @@ readonly class ConfigurationController {
                 $this->configurationManager->SetCollaboraDictionaries($collaboraDictionaries);
             }
 
-            if (isset($request->getParsedBody()['delete_borg_backup_host_location'])) {
-                $this->configurationManager->DeleteBorgBackupHostLocation();
+            if (isset($request->getParsedBody()['delete_borg_backup_location_vars'])) {
+                $this->configurationManager->DeleteBorgBackupLocationVars();
             }
 
             return $response->withStatus(201)->withHeader('Location', '/');

php/src/Data/ConfigurationManager.php

@@ -439,48 +439,61 @@ class ConfigurationManager
     /**
      * @throws InvalidSettingConfigurationException
      */
-    public function SetBorgBackupHostLocation(string $location) : void {
-        $isValidPath = false;
-        if (str_starts_with($location, '/') && !str_ends_with($location, '/')) {
-            $isValidPath = true;
-        } elseif ($location === 'nextcloud_aio_backupdir') {
-            $isValidPath = true;
-        }
-
-        if (!$isValidPath) {
-            throw new InvalidSettingConfigurationException("The path must start with '/', and must not end with '/'!");
-        }
-
+    public function SetBorgLocationVars(string $location, string $repo) : void {
+        $this->ValidateBorgLocationVars($location, $repo);
 
         $config = $this->GetConfig();
         $config['borg_backup_host_location'] = $location;
+        $config['borg_remote_repo'] = $repo;
         $this->WriteConfig($config);
     }
 
-    public function DeleteBorgBackupHostLocation() : void {
-        $config = $this->GetConfig();
-        $config['borg_backup_host_location'] = '';
-        $this->WriteConfig($config);
-    }
-
-        /**
-     * @throws InvalidSettingConfigurationException
-     */
-    public function SetBorgRestoreHostLocationAndPassword(string $location, string $password) : void {
-        if ($location === '') {
-            throw new InvalidSettingConfigurationException("Please enter a path!");
+    private function ValidateBorgLocationVars(string $location, string $repo) : void {
+        if ($location === '' && $repo === '') {
+            throw new InvalidSettingConfigurationException("Please enter a path or a remote repo url!");
+        } elseif ($location !== '' && $repo !== '') {
+            throw new InvalidSettingConfigurationException("Location and remote repo url are mutually exclusive!");
         }
         
-        $isValidPath = false;
-        if (str_starts_with($location, '/') && !str_ends_with($location, '/')) {
-            $isValidPath = true;
-        } elseif ($location === 'nextcloud_aio_backupdir') {
-            $isValidPath = true;
-        }
+        if ($location !== '') {
+            $isValidPath = false;
+            if (str_starts_with($location, '/') && !str_ends_with($location, '/')) {
+                $isValidPath = true;
+            } elseif ($location === 'nextcloud_aio_backupdir') {
+                $isValidPath = true;
+            }
 
-        if (!$isValidPath) {
-            throw new InvalidSettingConfigurationException("The path must start with '/', and must not end with '/'!");
+            if (!$isValidPath) {
+                throw new InvalidSettingConfigurationException("The path must start with '/', and must not end with '/'!");
+            }
+        } else {
+            $this->ValidateBorgRemoteRepo($repo);
         }
+    }
+
+    private function ValidateBorgRemoteRepo(string $repo) : void {
+        $commonMsg = "For valid urls, see the remote examples at https://borgbackup.readthedocs.io/en/stable/usage/general.html#repository-urls";
+        if ($repo === "") {
+            // Ok, remote repo is optional
+        } elseif (!str_contains($repo, "@")) {
+            throw new InvalidSettingConfigurationException("The remote repo must contain '@'. $commonMsg");
+        } elseif (!str_contains($repo, ":")) {
+            throw new InvalidSettingConfigurationException("The remote repo must contain ':'. $commonMsg");
+        }
+    }
+
+    public function DeleteBorgBackupLocationVars() : void {
+        $config = $this->GetConfig();
+        $config['borg_backup_host_location'] = '';
+        $config['borg_remote_repo'] = '';
+        $this->WriteConfig($config);
+    }
+
+    /**
+     * @throws InvalidSettingConfigurationException
+     */
+    public function SetBorgRestoreLocationVarsAndPassword(string $location, string $repo, string $password) : void {
+        $this->ValidateBorgLocationVars($location, $repo);
 
         if ($password === '') {
             throw new InvalidSettingConfigurationException("Please enter the password!");
@@ -488,6 +501,7 @@ class ConfigurationManager
 
         $config = $this->GetConfig();
         $config['borg_backup_host_location'] = $location;
+        $config['borg_remote_repo'] = $repo;
         $config['borg_restore_password'] = $password;
         $config['instance_restore_attempt'] = 1;
         $this->WriteConfig($config);
@@ -582,6 +596,23 @@ class ConfigurationManager
         return $config['borg_backup_host_location'];
     }
 
+    public function GetBorgRemoteRepo() : string {
+        $config = $this->GetConfig();
+        if(!isset($config['borg_remote_repo'])) {
+            $config['borg_remote_repo'] = '';
+        }
+
+        return $config['borg_remote_repo'];
+    }
+
+    public function GetBorgPublicKey() : string {
+        if (!file_exists(DataConst::GetBackupPublicKey())) {
+            return "";
+        }
+        
+        return trim(file_get_contents(DataConst::GetBackupPublicKey()));
+    }
+
     public function GetBorgRestorePassword() : string {
         $config = $this->GetConfig();
         if(!isset($config['borg_restore_password'])) {

php/src/Data/DataConst.php

@@ -23,6 +23,10 @@ class DataConst {
         return self::GetDataDirectory() . '/configuration.json';
     }
 
+    public static function GetBackupPublicKey() : string {
+        return self::GetDataDirectory() . '/id_borg.pub';
+    }
+
     public static function GetBackupSecretFile() : string {
         return self::GetDataDirectory() . '/backupsecret';
     }

php/src/Docker/DockerActionManager.php

@@ -265,6 +265,8 @@ readonly class DockerActionManager {
                     $replacements[1] = $this->configurationManager->GetBaseDN();
                 } elseif ($out[1] === 'AIO_TOKEN') {
                     $replacements[1] = $this->configurationManager->GetToken();
+                } elseif ($out[1] === 'BORGBACKUP_REMOTE_REPO') {
+                    $replacements[1] = $this->configurationManager->GetBorgRemoteRepo();
                 } elseif ($out[1] === 'BORGBACKUP_MODE') {
                     $replacements[1] = $this->configurationManager->GetBackupMode();
                 } elseif ($out[1] === 'AIO_URL') {

php/templates/containers.twig

@@ -25,6 +25,7 @@
             {# timezone-prefill #}
             <script type="text/javascript" src="timezone.js"></script>
 
+            {% set hasBackupLocation = borg_backup_host_location or borg_remote_repo %}
             {% set isAnyRunning = false %}
             {% set isAnyRestarting = false %}
             {% set isWatchtowerRunning = false %}
@@ -90,7 +91,7 @@
                             <input type="submit" value="Update mastercontainer" />
                         </form>
                     {% else %}
-                        {% if borg_backup_host_location == '' and borg_restore_password == '' %}
+                        {% if not hasBackupLocation %}
                             <p>The official Nextcloud installation method. Nextcloud All-in-One provides easy deployment and maintenance with most features included in this one Nextcloud instance.</p>
                             <p>You can either create a new AIO instance or restore a former AIO instance from backup. See the two sections below.</p>
                             {{ include('includes/aio-config.twig') }}
@@ -130,7 +131,7 @@
                         {% endif %}
 
                         {% if is_instance_restore_attempt == false %}
-                            {% if borg_backup_host_location != '' and borg_restore_password != '' %}
+                            {% if hasBackupLocation %}
                                 {% if borg_backup_mode in ['test', 'check'] %}
                                     {% if backup_exit_code > 0 %}
                                         <p><span class="status error"></span> Last {{ borg_backup_mode }} failed! (<a href="/api/docker/logs?id=nextcloud-aio-borgbackup" target="_blank" rel="noopener">Logs</a>)</p>
@@ -179,11 +180,23 @@
                                 {% endif %}
                             {% endif %}
 
-                            {% if borg_backup_host_location == '' or borg_restore_password == '' or borg_backup_mode not in ['test', 'check', ''] or backup_exit_code > 0 %}
-                                <p>Please enter the location of the backup archive on your host and the encryption password of the backup archive below:</p>
+                            {% if not hasBackupLocation or borg_backup_mode not in ['test', 'check', ''] or backup_exit_code > 0 %}
+                                {% if borg_remote_repo and backup_exit_code > 0 %}
+                                <p>
+                                You may still need to authorize this pubkey on your borg remote:<br><strong>{{ borg_public_key }}</strong><br>
+                                To try again, resubmit your location and rerun the test.
+                                </p>
+                                {% endif %}
+
+                                <p>
+                                Please enter the location of the backup archive on your host or a
+                                <a href="https://borgbackup.readthedocs.io/en/stable/usage/general.html#repository-urls">remote borg repo url</a>
+                                if stored remotely; and the encryption password of the backup archive below:
+                                </p>
                                 <form method="POST" action="/api/configuration" class="xhr">
-                                    <input type="text" name="borg_restore_host_location" value="{{borg_backup_host_location}}" placeholder="/mnt/backup"/>
-                                    <input type="text" name="borg_restore_password" value="{{borg_restore_password}}" placeholder="encryption password"/>
+                                    <label>Local backup location</label> <input type="text" name="borg_restore_host_location" value="{{borg_backup_host_location}}" placeholder="/mnt/backup"/><br>
+                                    <label>Remote borg repo</label> <input type="text" name="borg_restore_remote_repo" value="{{borg_remote_repo}}" placeholder="user@host:/path/to/repo"/><br>
+                                    <label>Borg passphrase</label> <input type="text" name="borg_restore_password" value="{{borg_restore_password}}" placeholder="encryption password"/><br>
                                     <input type="hidden" name="{{csrf.keys.name}}" value="{{csrf.name}}">
                                     <input type="hidden" name="{{csrf.keys.value}}" value="{{csrf.value}}">
                                     <input type="submit" value="Submit location and encryption password" />
@@ -220,19 +233,19 @@
                 {% if domain != "" %}
                     {% if isAnyRunning == true %}
                         {% if isApacheStarting != true %}
-                            {% if borg_backup_host_location != '' %}
+                            {% if hasBackupLocation %}
                                 <details>
                                 <summary>Click here to reveal the initial Nextcloud credentials</summary>
                             {% endif %}
                                     <p>Initial Nextcloud username: <strong>admin</strong></p>
-                            {% if borg_backup_host_location != '' %}
+                            {% if hasBackupLocation %}
                                 {# nextcloud_password needs to be duplicated due to a bug in Firefox. See https://github.com/nextcloud/all-in-one/issues/638. #}
                                 <p>Initial Nextcloud password: <strong>{{ nextcloud_password }}</strong></p></details>
                             {% else %}
                                 <p>Initial Nextcloud password: <strong>{{ nextcloud_password }}</strong></p>
                             {% endif %}
                             <p><a href="https://{{ domain }}" class="button" target="_blank" rel="noopener">Open your Nextcloud ↗</a></p>
-                            {% if borg_backup_host_location == '' %}
+                            {% if not hasBackupLocation %}
                                 <p>If your Nextcloud does not open when clicking the button above, see <strong><a href="https://github.com/nextcloud/all-in-one/discussions/2105">this documentation</a></strong></p>
                             {% endif %}
                         {% else %}
@@ -371,11 +384,16 @@
                             <h2>Backup and restore</h2>
                             <p>The backup section is disabled via environmental variable.</p>
                         {% else %}
-                            {% if is_backup_container_running == false and borg_backup_host_location == "" and isApacheStarting != true %}
+                            {% if is_backup_container_running == false and not hasBackupLocation and isApacheStarting != true %}
                                 <h2>Backup and restore</h2>
                                 <p>Please enter the directory path below where backups will be created on the host system. It's best to choose a location on a separate drive and not on your root drive.</p>
+                                <p>
+                                To store backups remotely instead, fill in the
+                                <a href="https://borgbackup.readthedocs.io/en/stable/usage/general.html#repository-urls">remote borg repo url</a>.
+                                </p>
                                 <form method="POST" action="/api/configuration" class="xhr">
-                                    <input type="text" name="borg_backup_host_location" placeholder="/mnt/backup"/>
+                                    <label>Local backup location</label> <input type="text" name="borg_backup_host_location" placeholder="/mnt/backup"/><br>
+                                    <label>Remote borg repo</label> <input type="text" name="borg_remote_repo" placeholder="user@host:/path/to/repo"/><br>
                                     <input type="hidden" name="{{csrf.keys.name}}" value="{{csrf.name}}">
                                     <input type="hidden" name="{{csrf.keys.value}}" value="{{csrf.value}}">
                                     <input type="submit" value="Submit backup location" />
@@ -386,7 +404,7 @@
 
                         {% if is_backup_section_enabled == true %}
 
-                            {% if borg_backup_host_location != "" %}
+                            {% if hasBackupLocation %}
                                 {% if is_backup_container_running == false %}
                                     <h2>Backup and restore</h2>
                                     {% if backup_exit_code > 0 %}
@@ -404,9 +422,19 @@
                                             </details>
                                         {% endif %}
                                         {% if has_backup_run_once == false %}
+                                            <p>The initial backup was not successful.</p>
+
+                                            {% if borg_remote_repo %}
+                                            <p>
+                                            You may still need to authorize this pubkey on your borg remote:<br><strong>{{ borg_public_key }}</strong><br>
+                                            To try again, click <strong>Create backup</strong>.
+                                            </p>
+                                            {% endif %}
+                                            
                                             <p>You may change the backup path again since the initial backup was not successful. After submitting the new value, you need to click on <strong>Create Backup</strong> to test the new value.</p>
                                             <form method="POST" action="/api/configuration" class="xhr">
-                                                <input type="text" value="{{borg_backup_host_location}}" name="borg_backup_host_location" placeholder="/mnt/backup" />
+                                                <label>Local backup location</label> <input type="text" name="borg_backup_host_location" placeholder="/mnt/backup"/><br>
+                                                <label>Remote borg repo</label> <input type="text" name="borg_remote_repo" placeholder="user@host:/path/to/repo"/><br>
                                                 <input type="hidden" name="{{csrf.keys.name}}" value="{{csrf.name}}">
                                                 <input type="hidden" name="{{csrf.keys.value}}" value="{{csrf.value}}">
                                                 <input type="submit" value="Set backup location again" />
@@ -432,7 +460,17 @@
                                     <p>All important data from your Nextcloud AIO instance such as the database, your files and the mastercontainer's configuration files, will be backed up.</p>
                                     <p>The backup uses a tool called <a href="https://github.com/borgbackup/borg#what-is-borgbackup"><strong>BorgBackup</strong></a>, a well-known server backup tool that efficiently backs up your files and encrypts them on the fly.</p>
                                     <p>By using this tool, backups are incremental, differential, compressed and encrypted – so only the first backup will take a while. Further backups should be fast as only changes are taken into account.</p>
-                                    <p>Backups will be created in the following directory on the host: <strong>{{ borg_backup_host_location }}/borg</strong></p>
+                                    {% if borg_remote_repo != '' %}
+                                        <p>
+                                        Backups get created remotely at:<br>
+                                        <strong>{{ borg_remote_repo }}</strong>
+                                        {% if has_backup_run_once == true %}
+                                        <br/>Your borg ssh public key is:<br><strong>{{ borg_public_key }}</strong>
+                                        {% endif %}
+                                        </p>
+                                    {% else %}
+                                        <p>Backups will be created in the following directory on the host: <strong>{{ borg_backup_host_location }}/borg</strong></p>
+                                    {% endif %}
                                     <p>Be aware that this solution does not backup files and folders that are mounted into Nextcloud using the external storage app, but you can add further Docker volumes and host paths that you want to back up after the initial backup is done.</p>
                                     <p>For information about backup retention, see <strong><a href="https://github.com/nextcloud/all-in-one#how-to-adjust-borgs-retention-policy">this</a></strong>.</p>
                                     <p>Daily backups can be enabled after the initial backup is done. Enabling this also allows you to enable an option to update all containers, Nextcloud, and its apps automatically.</p>
@@ -448,10 +486,14 @@
                                         </form>
 
                                         {% if has_backup_run_once == false %}
-                                            <h3>Reset backup host location</h3>
-                                            <p>If the configured backup host location <strong>{{ borg_backup_host_location }}</strong> is wrong, you can reset it by clicking on the button below.</p>
+                                            <h3>Reset backup location</h3>
+                                            <p>
+                                            If the configured backup host location <strong>{{ borg_backup_host_location }}</strong>
+                                            {% if borg_remote_repo %}or the remote repo <strong>{{ borg_remote_repo }}</strong> is wrong{% endif %},
+                                            you can reset it by clicking on the button below.
+                                            </p>
                                             <form method="POST" action="/api/configuration" class="xhr">
-                                                <input type="hidden" name="delete_borg_backup_host_location" value="yes"/>
+                                                <input type="hidden" name="delete_borg_backup_location_vars" value="yes"/>
                                                 <input type="hidden" name="{{csrf.keys.name}}" value="{{csrf.name}}">
                                                 <input type="hidden" name="{{csrf.keys.value}}" value="{{csrf.value}}">
                                                 <input type="submit" value="Reset backup location" />

readme.md

@@ -67,10 +67,10 @@ Included are:
 - Many of the included containers have a read-only root-FS (good for security)
 - Included containers run in its own docker network (good for security) and only really necessary ports are exposed on the host
 - [Multiple instances on one server](https://github.com/nextcloud/all-in-one/blob/main/multiple-instances.md) are doable without having to deal with VMs
-- Adjustable backup path from the AIO interface (good to put the backups e.g. on a different drive)
+- Adjustable backup path or remote borg repository from the AIO interface (good to put the backups e.g. on a different drive if using a local backup path)
 - Possibility included to also back up external Docker Volumes or Host paths (can be used for host backups)
 - Borg backup can be completely managed from the AIO interface, including backup creation, backup restore, backup integrity check and integrity-repair
-- [Remote backups](https://github.com/nextcloud/all-in-one#are-remote-borg-backups-supported) are indirectly possible
+- Other forms of [remote backup](https://github.com/nextcloud/all-in-one#are-remote-borg-backups-supported) are indirectly possible
 - Updates and backups can be [run from an external script](https://github.com/nextcloud/all-in-one#how-to-stopstartupdate-containers-or-trigger-the-daily-backup-from-a-script-externally). See [this documentation](https://github.com/nextcloud/all-in-one#how-to-enable-automatic-updates-without-creating-a-backup-beforehand) for a complete example.
 
 </details>
@@ -383,11 +383,11 @@ Here is how to reset the AIO instance properly:
 1. And you are done! Now feel free to start over with the recommended docker run command!
 
 ### Backup solution
-Nextcloud AIO provides a local backup solution based on [BorgBackup](https://github.com/borgbackup/borg#what-is-borgbackup). These backups act as a local restore point in case the installation gets corrupted. By using this tool, backups are incremental, differential, compressed and encrypted – so only the first backup will take a while. Further backups should be fast as only changes are taken into account.
+Nextcloud AIO provides a backup solution based on [BorgBackup](https://github.com/borgbackup/borg#what-is-borgbackup). These backups act as a restore point in case the installation gets corrupted. By using this tool, backups are incremental, differential, compressed and encrypted – so only the first backup will take a while. Further backups should be fast as only changes are taken into account.
 
 It is recommended to create a backup before any container update. By doing this, you will be safe regarding any possible complication during updates because you will be able to restore the whole instance with basically one click. 
 
-The restore process should be pretty fast as rsync is used to restore the chosen backup which only transfers changed files and deletes additional ones.
+For local backups, the restore process should be pretty fast as rsync is used to restore the chosen backup which only transfers changed files and deletes additional ones. For remote borg backups, the whole backup archive is extracted from the remote, which depending on how clever `borg extract` is, may require downloading the whole archive.
 
 If you connect an external drive to your host, and choose the backup directory to be on that drive, you are also kind of safe against drive failures of the drive where the docker volumes are stored on. 
 
@@ -404,6 +404,14 @@ If you connect an external drive to your host, and choose the backup directory t
 
 </details>
 
+If you want to back up directly to a remote borg repository:
+
+1. Create your borg repository at the remote. Note down the repository URL for later.
+2. Open the AIO interface
+3. Under backup section, leave the local path blank and fill in the url to your borg repository that you noted down earlier.
+4. Click on `Create backup`, this will create an ssh key pair and fail because the remote doesn't trust this key yet. Copy the public key shown in AIO and add it to your authorized keys on the remote.
+5. Try again to create a backup, this time it should succeed.
+
 Backups can be created and restored in the AIO interface using the buttons `Create Backup` and `Restore selected backup`. Additionally, a backup check is provided that checks the integrity of your backups but it shouldn't be needed in most situations. 
 
 The backups themselves get encrypted with an encryption key that gets shown to you in the AIO interface. Please save that at a safe place as you will not be able to restore from backup without this key.
@@ -421,8 +429,10 @@ Backed up will get all important data of your Nextcloud AIO instance like the da
 The built-in borg-based backup solution has by default a retention policy of `--keep-within=7d --keep-weekly=4 --keep-monthly=6`. See https://borgbackup.readthedocs.io/en/stable/usage/prune.html for what these values mean. You can adjust the retention policy by providing `--env BORG_RETENTION_POLICY="--keep-within=7d --keep-weekly=4 --keep-monthly=6"` to the docker run command of the mastercontainer (but before the last line `nextcloud/all-in-one:latest`! If it was started already, you will need to stop the mastercontainer, remove it (no data will be lost) and recreate it using the docker run command that you initially used) and customize the value to your fitting. ⚠️ Please make sure that this value is valid, otherwise backup pruning will bug out!
 
 #### Are remote borg backups supported?
+Backing up directly to a remote borg repository is supported. This avoids having to store a local copy of your backups, supports append-only borg keys to counter ransomware and allows using the AIO interface to manage your backups.
+
+Some alternatives, which do not have all the above benefits:
 
-Not directly but you have multiple options to achieve this:
 - Mount a network FS like SSHFS, SMB or NFS in the directory that you enter in AIO as backup directory
 - Use rsync or rclone for syncing the borg backup archive that AIO creates locally to a remote target (make sure to lock the backup archive correctly before starting the sync; search for "aio-lockfile"; you can find a local example script here: https://github.com/nextcloud/all-in-one#sync-the-backup-regularly-to-another-drive)
 - You can find a well written guide that uses rclone and e.g. BorgBase for remote backups here: https://github.com/nextcloud/all-in-one/discussions/2247
@@ -457,8 +467,14 @@ You can open the BorgBackup archives on your host by following these steps:<br>
 # Install borgbackup on the host
 sudo apt update && sudo apt install borgbackup
 
-# Mount the archives to /tmp/borg (if you are using the default backup location /mnt/backup/borg)
-sudo mkdir -p /tmp/borg && sudo borg mount "/mnt/backup/borg" /tmp/borg
+# In any shell where you use borg, you must first export this variable
+# If you are using the default backup location /mnt/backup/borg
+export BORG_REPO='/mnt/backup/borg'
+# or if you are using a remote repository
+export BORG_REPO='user@host:/path/to/repo'
+
+# Mount the archives to /tmp/borg
+sudo mkdir -p /tmp/borg && sudo borg mount "$BORG_REPO" /tmp/borg
 
 # After entering your repository key successfully, you should be able to access all archives in /tmp/borg
 # You can now do whatever you want by syncing them to a different place using rsync or doing other things
@@ -478,18 +494,24 @@ You can delete BorgBackup archives on your host manually by following these step
 # Install borgbackup on the host
 sudo apt update && sudo apt install borgbackup
 
+# In any shell where you use borg, you must first export this variable
+# If you are using the default backup location /mnt/backup/borg
+export BORG_REPO='/mnt/backup/borg'
+# or if you are using a remote repository
+export BORG_REPO='user@host:/path/to/repo'
+
 # List all archives (if you are using the default backup location /mnt/backup/borg)
-sudo borg list "/mnt/backup/borg"
+sudo borg list
 
 # After entering your repository key successfully, you should now see a list of all backup archives
 # An example backup archive might be called 20220223_174237-nextcloud-aio
 # Then you can simply delete the archive with:
-sudo borg delete --stats --progress "/mnt/backup/borg::20220223_174237-nextcloud-aio"
+sudo borg delete --stats --progress "::20220223_174237-nextcloud-aio"
 
 # If borg 1.2.0 or higher is installed, you then need to run borg compact in order to clean up the freed space
 sudo borg --version
 # If version number of the command above is higher than 1.2.0 you need to run the command below:
-sudo borg compact "/mnt/backup/borg"
+sudo borg compact
 
 ```
 
@@ -498,8 +520,8 @@ You can do so by clicking on the `Check backup integrity` button or `Create back
 
 ---
 
-#### Sync the backup regularly to another drive
-For increased backup security, you might consider syncing the backup repository regularly to another drive.
+#### Sync local backups regularly to another drive
+For increased backup security, you might consider syncing the local backup repository regularly to another drive.
 
 To do that, first add the drive to `/etc/fstab` so that it is able to get automatically mounted and then create a script that does all the things automatically. Here is an example for such a script:
 
@@ -600,7 +622,7 @@ Afterwards apply the correct permissions with `sudo chown root:root /root/backup
 > [!WARNING]  
 > The below script will only work after the initial setup of AIO. So you will always need to first visit the AIO interface, type in your domain and start the containers the first time or restore an older AIO instance from its borg backup before you can use the script.
 
-You can do so by running the `/daily-backup.sh` script that is stored in the mastercontainer. It accepts the following environmental varilables:
+You can do so by running the `/daily-backup.sh` script that is stored in the mastercontainer. It accepts the following environment variables:
 - `AUTOMATIC_UPDATES` if set to `1`, it will automatically stop the containers, update them and start them including the mastercontainer. If the mastercontainer gets updated, this script's execution will stop as soon as the mastercontainer gets stopped. You can then wait until it is started again and run the script with this flag again in order to update all containers correctly afterwards.
 - `DAILY_BACKUP` if set to `1`, it will automatically stop the containers and create a backup. If you want to start them again afterwards, you may have a look at the `START_CONTAINERS` option.
 - `START_CONTAINERS` if set to `1`, it will automatically start the containers without updating them.