Fix a bug that causes premature termination of processing (#2283)

It turns out that trying to reimport a subsequently non-existent record
(i.e. when the originating CVE was rejected), the source file no longer
exists in GCS and the retrieval failure raises an exception, which is
being silently caught, which then caused the transaction to terminate.

So don't silently catch exceptions, other than the general one used to
terminate in dry-run mode.

Also removed unnecessary copy-pasta for this program's use case (it's
hard-limited to 30 records at a time due to Datastore query limits, so
batching makes no sense).

tools/datafix/reimport_gcs_record.py

@@ -16,14 +16,14 @@
 
 from google.cloud import datastore
 from google.cloud import storage
+from google.cloud.exceptions import NotFound
 from google.cloud.storage import retry
 from google.cloud.datastore.query import PropertyFilter
 
 import argparse
 import os
 import functools
 
-MAX_BATCH_SIZE = 500
 MAX_QUERY_SIZE = 30
 
 
@@ -168,29 +168,34 @@ def main() -> None:
   result_to_fix = [r for r in result if r['source_of_truth'] == 2]
   print(f"There are {len(result_to_fix)} bugs to operate on...")
 
-  # Chunk the results to modify in acceptibly sized batches for the API.
-  for batch in range(0, len(result_to_fix), MAX_BATCH_SIZE):
-    try:
-      with ds_client.transaction() as xact:
-        for bug in result_to_fix[batch:batch + MAX_BATCH_SIZE]:
-          bug_in_gcs = objname_for_bug(ds_client, bug)
-          if args.verbose:
-            print(f"Resetting creation time for {bug_in_gcs['uri']}")
-          if not args.dryrun:
+  try:
+    with ds_client.transaction() as xact:
+      for bug in result_to_fix:
+        bug_in_gcs = objname_for_bug(ds_client, bug)
+        if args.verbose:
+          print(f"Resetting creation time for {bug_in_gcs['uri']}")
+        if not args.dryrun:
+          try:
             reset_object_creation(bug_in_gcs["bucket"], bug_in_gcs["path"],
                                   args.tmpdir)
-          bug["import_last_modified"] = None
-          if args.verbose:
-            print(f"Resetting import_last_modified for {bug['db_id']}")
-          print(f"Review at {url_base}{bug['db_id']} when reimport completes.")
-          xact.put(bug)
-        if args.dryrun:
-          raise Exception("Dry run mode. Preventing transaction from commiting")  # pylint: disable=broad-exception-raised
-    except Exception as e:
-      # Don't have the first batch's transaction-aborting exception stop
-      # subsequent batches from being attempted.
-      if args.dryrun and e.args[0].startswith("Dry run mode"):
-        pass
+          except NotFound as e:
+            if args.verbose:
+              print(f"Skipping, got {e}\n")
+            continue
+        bug["import_last_modified"] = None
+        if args.verbose:
+          print(f"Resetting import_last_modified for {bug['db_id']}")
+        print(f"Review at {url_base}{bug['db_id']} when reimport completes.")
+        xact.put(bug)
+      if args.dryrun:
+        raise Exception("Dry run mode. Preventing transaction from commiting")  # pylint: disable=broad-exception-raised
+  except Exception as e:
+    # Don't have the first batch's transaction-aborting exception stop
+    # subsequent batches from being attempted.
+    if args.dryrun and e.args[0].startswith("Dry run mode"):
+      pass
+    else:
+      raise
 
 
 if __name__ == "__main__":