exclude iceberg from duckdb s3-compatibility test

dlt/destinations/impl/filesystem/sql_client.py

@@ -169,8 +169,9 @@ def create_authentication(self, persistent: bool = False, secret_name: str = Non
         # native google storage implementation is not supported..
         elif self.fs_client.config.protocol in ["gs", "gcs"]:
             logger.warn(
-                "For gs/gcs access via duckdb please use the gs/gcs s3 compatibility layer. Falling"
-                " back to fsspec."
+                "For gs/gcs access via duckdb please use the gs/gcs s3 compatibility layer if"
+                " possible (not supported when using `iceberg` table format). Falling back to"
+                " fsspec."
             )
             self._conn.register_filesystem(self.fs_client.fs_client)
 

docs/website/docs/dlt-ecosystem/destinations/filesystem.md

@@ -108,7 +108,8 @@ You need to create an S3 bucket and a user who can access that bucket. dlt does
 
 #### Using S3 compatible storage
 
-To use an S3 compatible storage other than AWS S3, such as [MinIO](https://min.io/) or [Cloudflare R2](https://www.cloudflare.com/en-ca/developer-platform/r2/), you may supply an `endpoint_url` in the config. This should be set along with AWS credentials:
+To use an S3 compatible storage other than AWS S3, such as [MinIO](https://min.io/), [Cloudflare R2](https://www.cloudflare.com/en-ca/developer-platform/r2/) or [Google 
+Cloud Storage](https://cloud.google.com/storage/docs/interoperability), you may supply an `endpoint_url` in the config. This should be set along with AWS credentials:
 
 ```toml
 [destination.filesystem]
@@ -732,6 +733,10 @@ Note that not all authentication methods are supported when using table formats
 | [OAuth](../destinations/bigquery.md#oauth-20-authentication) | ❌ | ✅ |
 | [Application Default Credentials](bigquery.md#using-default-credentials) | ✅ | ❌ |
 
+:::note
+The [S3-compatible](#using-s3-compatible-storage) interface for Google Cloud Storage is not supported when using `iceberg`.
+:::
+
 #### Iceberg Azure scheme
 The `az` [scheme](#supported-schemes) is not supported when using the `iceberg` table format. Please use the `abfss` scheme. This is because `pyiceberg`, which `dlt` used under the hood, currently does not support `az`.
 

tests/load/filesystem/test_sql_client.py

@@ -303,8 +303,9 @@ def test_table_formats(
     # in case of gcs we use the s3 compat layer for reading
     # for writing we still need to use the gc authentication, as delta_rs seems to use
     # methods on the s3 interface that are not implemented by gcs
+    # s3 compat layer does not work with `iceberg` table format
     access_pipeline = pipeline
-    if destination_config.bucket_url == GCS_BUCKET:
+    if destination_config.bucket_url == GCS_BUCKET and destination_config.table_format != "iceberg":
         gcp_bucket = filesystem(
             GCS_BUCKET.replace("gs://", "s3://"), destination_name="filesystem_s3_gcs_comp"
         )