UN-3358 [FIX] Drop cross-region S3 buckets from connector listing

unstract/connectors/src/unstract/connectors/filesystems/minio/exceptions.py

@@ -8,20 +8,24 @@
 class BucketProbeDisposition(Enum):
     """Action for a `list_objects_v2` probe failure, per S3 error code."""
 
-    DROP = "drop"  # Hide the bucket (no access, or bucket gone).
-    FAIL_OPEN = "fail_open"  # Region mismatch — keep bucket visible.
+    DROP = "drop"  # Hide the bucket (no access, bucket gone, or unreachable).
+    FAIL_OPEN = "fail_open"  # Keep the bucket visible despite the probe error.
     RETRY_FAIL_OPEN = "retry_fail_open"  # Throttled — retry once, then keep.
 
 
 # S3 `Error.Code` → probe disposition. Unlisted codes propagate.
 # `RequestTimeTooSkewed` is omitted deliberately: it's a system-wide clock
 # issue, not a bucket outcome — let it surface via `handle_s3fs_exception`.
+# `PermanentRedirect` / `IllegalLocationConstraintException` are dropped: the
+# connector is pinned to one `endpoint_url`, so cross-region buckets can't
+# be browsed through it regardless of IAM — listing them only surfaces a
+# confusing `[Errno 78]` on click.
 BUCKET_PROBE_DISPOSITION: dict[str, BucketProbeDisposition] = {
     "AccessDenied": BucketProbeDisposition.DROP,
     "AllAccessDisabled": BucketProbeDisposition.DROP,
     "NoSuchBucket": BucketProbeDisposition.DROP,
-    "PermanentRedirect": BucketProbeDisposition.FAIL_OPEN,
-    "IllegalLocationConstraintException": BucketProbeDisposition.FAIL_OPEN,
+    "PermanentRedirect": BucketProbeDisposition.DROP,
+    "IllegalLocationConstraintException": BucketProbeDisposition.DROP,
     "SlowDown": BucketProbeDisposition.RETRY_FAIL_OPEN,
     "Throttling": BucketProbeDisposition.RETRY_FAIL_OPEN,
     "ThrottlingException": BucketProbeDisposition.RETRY_FAIL_OPEN,

unstract/connectors/tests/filesystems/test_miniofs.py

@@ -104,15 +104,31 @@ def test_no_such_bucket_is_dropped(self) -> None:
         ):
             self.assertFalse(asyncio.run(fs._is_bucket_accessible("deleted")))
 
-    def test_permanent_redirect_bucket_is_kept(self) -> None:
-        # Fail-open: region mismatch keeps the bucket listed.
+    def test_permanent_redirect_bucket_is_dropped(self) -> None:
+        # Connector pins one endpoint_url; cross-region buckets are unreachable
+        # via this connector regardless of IAM, so drop them rather than fail
+        # later with [Errno 78] on click.
         fs = self._make_fs()
         with patch.object(
             fs,
             "_call_s3",
             new=AsyncMock(side_effect=_translated_error("PermanentRedirect")),
         ):
-            self.assertTrue(asyncio.run(fs._is_bucket_accessible("other-region")))
+            self.assertFalse(asyncio.run(fs._is_bucket_accessible("other-region")))
+
+    def test_illegal_location_constraint_bucket_is_dropped(self) -> None:
+        # Companion to PermanentRedirect: same cross-region condition surfaced
+        # as a 400 instead of a 301. Guards against a future edit reverting
+        # only one of the two cross-region entries in BUCKET_PROBE_DISPOSITION.
+        fs = self._make_fs()
+        with patch.object(
+            fs,
+            "_call_s3",
+            new=AsyncMock(
+                side_effect=_translated_error("IllegalLocationConstraintException")
+            ),
+        ):
+            self.assertFalse(asyncio.run(fs._is_bucket_accessible("wrong-region")))
 
     def test_throttling_retries_then_fails_open(self) -> None:
         fs = self._make_fs()