fix(linstor): Docstrings, bugfix, simplifications.

Don't except/raise LinstorDatabaseBackupError in _check_database_backup().
Simpler glob search for backup files, as the date is properly validated by datetime.
Fix bug in database_backup_age().

Signed-off-by: Arnaud Garcia-Fernandez <arnaud.garcia-fernandez@vates.tech>

Author: Ythogtha

drivers/LinstorSR.py

@@ -1592,16 +1592,15 @@ def database_backup(self, name=""):
         """
         Generate a new database backup file.
         This operation should not prevent the underlying action to be successful.
-        Hence all Exceptions are caught and re-raised only if asked to.
-        delay: skip backup if the last one was generated less than delay seconds ago.
+        Hence all Exceptions are caught and logged.
         """
         if not self._linstor:
             self._reconnect()
         try:
             self._linstor.database_backup(name)
         except Exception as e:
             util.SMlog(
-                "[database_backup] Error during creation: {}".format(e),
+                f"[database_backup] Error during creation: {e}",
                 priority=util.LOG_ERR,
             )
 

drivers/linstorvolumemanager.py

@@ -1784,7 +1784,7 @@ def database_backup_age(cls):
         If not called on the Controller, since backups are not available,
         returns a huge value (a timestamp of now).
         """
-        return (datetime.now() - cls._get_latest_database_backup()).total_seconds()
+        return (datetime.now() - cls._get_latest_database_backup()[1]).total_seconds()
 
     def database_backup(self, name=""):
         # Create new backup
@@ -2676,27 +2676,49 @@ def _get_volume_properties(self, volume_uuid):
 
     @classmethod
     def _list_database_backup(cls, database_backup_dir):
+        """
+        List all visible backup files in database_backup_dir.
+        DATABASE_BACKUP_DIR_MAIN is only available on the Linstor Controller.
+        DATABASE_BACKUP_DIR_SPARE will list backups previously made when the Host was the Linstor Controller.
+        This may not be useful information if it is not the Controller anymore.
+        """
         for path in database_backup_dir.glob(DATABASE_BACKUP_NAME_FORMAT.format(
-                "20[0-9][0-9][01][0-9][0-3][0-9]_[0-2][0-9][0-5][0-9][0-5][0-9]", "*") + ".zip"):
+                "[0-9]" * 8 + "_" + "[0-9]" * 6, "*") + ".zip"):
             try:
                 yield path, datetime.strptime(path.name.split("-")[1], DATABASE_BACKUP_DATE_FORMAT)
             except (ValueError, IndexError):
                 continue
 
     @classmethod
     def _get_sorted_database_backup(cls, database_backup_dir):
+        """
+        Return list of backups in database_backup_dir, alongside their creation date.
+        Sorted by date from the more recent to the older one.
+        """
         return sorted(cls._list_database_backup(database_backup_dir),
                       reverse=True,
                       key=lambda p: p[1])
 
     @classmethod
     def _get_latest_database_backup(cls):
+        """
+        Return the latest backup in DATABASE_BACKUP_DIR_MAIN, and its creation date.
+        Returns (None, timestamp(0)) when none are found.
+        None will be found if it is not called on the Linstor Controller.
+        (cf _list_database_backup)
+        """
         return max(cls._list_database_backup(DATABASE_BACKUP_DIR_MAIN),
                    default=(None, datetime.fromtimestamp(0)),
                    key=lambda p: p[1])
 
     @classmethod
     def _check_database_backup(cls, database_backup_file):
+        """
+        Make some validation of a database backup zip-file.
+        Check its a valid zipfile, and CRC-test its content.
+        Check it contains a non-empty linstordb.mv.db file.
+        Always raises a LinstorDatabaseBackupError if checks failed.
+        """
         try:
             with zipfile.ZipFile(database_backup_file, mode="r") as archive:
                 if archive.testzip() is not None:
@@ -2707,8 +2729,6 @@ def _check_database_backup(cls, database_backup_file):
                 linstordb = linstordb[0]
                 if linstordb.file_size == 0:
                     raise LinstorDatabaseBackupError("linstordb.mv.db is empty")
-        except LinstorDatabaseBackupError:
-            raise
         except (FileNotFoundError, zipfile.BadZipFile, zipfile.LargeZipFile) as e:
             raise LinstorDatabaseBackupError(e) from e