Add remote borg backup support

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/borg_excludes

@@ -0,0 +1,9 @@
+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

@@ -450,6 +450,7 @@
       "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 @@
         '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

@@ -32,15 +32,17 @@ public function SetConfig(Request $request, Response $response, array $args) : R
                 $this->configurationManager->ChangeMasterPassword($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'])) {
@@ -131,8 +133,8 @@ public function SetConfig(Request $request, Response $response, array $args) : R
                 $this->configurationManager->SetCollaboraDictionaries($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

@@ -424,55 +424,69 @@ public function GetAIOURL() : string {
     /**
      * @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 {
+    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 !== '' && $repo !== '') {
+            throw new InvalidSettingConfigurationException("Location and remote repo url are mutually exclusive!");
+        }
+
+        if ($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 '/'!");
+            }
+        } 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 SetBorgRestoreHostLocationAndPassword(string $location, string $password) : void {
-        if ($location === '') {
-            throw new InvalidSettingConfigurationException("Please enter a path!");
-        }
-
-        $isValidPath = false;
-        if (str_starts_with($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 SetBorgRestoreLocationVarsAndPassword(string $location, string $repo, string $password) : void {
+        $this->ValidateBorgLocationVars($location, $repo);
 
         if ($password === '') {
             throw new InvalidSettingConfigurationException("Please enter the password!");
         }
 
         $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);
@@ -567,6 +581,23 @@ public function GetBorgBackupHostLocation() : string {
         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 @@ public static function GetConfigFile() : string {
         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

@@ -287,6 +287,8 @@ public function CreateContainer(Container $container) : void {
                     $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') {