add: first backup feature

zfs-backup.py

@@ -47,7 +47,6 @@ def main():
 
 # TODO tests
 # TODO docstrings
-# TODO first backup
 # TODO --skip-import
 # TODO --skip-post-backup-scrub
 # TODO print time estimation while scrub is in progress
@@ -78,8 +77,10 @@ class Manager:
             if remote_dataset:
                 stream = self._send_incremental(local_dataset, remote_dataset)
             else:
-                # TODO ask for confirmation before sending
+                if self._ask_user_confirmation(local_dataset):
                     stream = self._send_absolute(local_dataset)
+                else:
+                    continue
             ZFS.receive(stream, self._external_pool)
 
     def _send_incremental(
@@ -139,6 +140,19 @@ class Manager:
         common_snapshots.sort()
         return common_snapshots[-1]
 
+    @staticmethod
+    def _ask_user_confirmation(dataset: Dataset) -> bool:
+        msg = f"Dataset {dataset.qualified_name} does not exist in backup pool. Backup? [y/n] "
+        reply = ""
+        while not reply:
+            reply = input(msg).lower()
+            if reply == "y":
+                return True
+            elif reply == "n":
+                return False
+            else:
+                reply = ""
+
 
 def _get_regex_matching_snapshots_with_tags(tags: list[str]):
     return "@" + ".*".join(tags)