Add logging to bucketfs (#101)

doc/changes/unreleased.md

@@ -1,5 +1,27 @@
 # Unreleased
 
+## Added 
+- Added logging support
+    **Overview**
+
+    The bucketfs logger can be referenced via `exasol.bucketfs`
+
+    ```python
+    import logging
+    # Get the logger for 'exasol.bucketfs'
+    logger = logging.getLogger('exasol.bucketfs')
+    ```
+
+    For most use cases it should be sufficient to just configure the root logger, in order
+    to retrieve the logs from bucketfs.
+
+    ```python
+    import logging
+
+    logging.basicConfig(level=logging.INFO)
+    ```
+
+
 ## Internal
 - Relock dependencies
 - Update abatilo/actions-poetry from `v2.1.4` to `v3.0.0`

doc/examples/logger.py

@@ -0,0 +1,26 @@
+import logging
+from exasol.bucketfs import Service
+
+logging.basicConfig(level=logging.INFO)
+
+# Advanced Logging
+import logging
+from exasol.bucketfs import Service
+
+# Attention:
+# It is essential to configure the root logger at the beginning of your script.
+# This ensures that log messages, including those from the bucketfs are handled correctly.
+# Without proper configuration, log messages might not appear as expected.
+logging.basicConfig(level=logging.INFO)
+
+# Explicityly Configure the bucketfs logger if you need to.
+#
+# 1. Get a reference to the bucketfs logger
+bucketfs_logger = logging.getLogger('exasol.bucketfs')
+
+# 2. Configure the bucketfs logger as needed
+# Note:
+#   By default bucketfs logger is set to NOTSET (https://docs.python.org/3.11/library/logging.html#logging.NOTSET)
+#   which should be sufficient in lots of cases where the root logger is configured approriately.
+bucketfs_logger.setLevel(logging.DEBUG)
+...

doc/user_guide/advanced.rst

@@ -39,3 +39,10 @@ Delete files from Bucket
    :start-after: # Expert/Mapped bucket API
 
 
+Configure logging
++++++++++++++++++
+
+.. literalinclude:: /examples/logger.py
+   :language: python3
+   :start-after: # Advanced Logging
+

doc/user_guide/basics.rst

@@ -74,3 +74,10 @@ Delete files from Bucket
    :end-before: # Expert/Mapped bucket API
 
 
+Configure logging
++++++++++++++++++
+
+.. literalinclude:: /examples/logger.py
+   :language: python3
+   :end-before: # Advanced Logging
+

exasol/bucketfs/__init__.py

@@ -46,6 +46,7 @@
 from __future__ import annotations
 
 import hashlib
+import logging
 from collections import defaultdict
 from pathlib import Path
 from typing import (
@@ -55,7 +56,6 @@
     Iterator,
     Mapping,
     MutableMapping,
-    Union,
 )
 from urllib.parse import urlparse
 
@@ -67,12 +67,15 @@
     "Service",
     "Bucket",
     "MappedBucket",
+    "BucketFsError",
     "as_bytes",
     "as_string",
     "as_file",
     "as_hash",
 ]
 
+_logger = logging.getLogger("exasol.bucketfs")
+
 
 class BucketFsError(Exception):
     """Error occurred while interacting with the bucket fs service."""
@@ -120,7 +123,7 @@ class Service:
     def __init__(
         self,
         url: str,
-        credentials: Mapping[str, Mapping[str, str]] = None,
+        credentials: Mapping[str, Mapping[str, str]] | None = None,
         verify: bool | str = True,
     ):
         """Create a new Service instance.
@@ -149,6 +152,7 @@ def buckets(self) -> MutableMapping[str, Bucket]:
         url = _build_url(service_url=self._url)
         response = requests.get(url, verify=self._verify)
         try:
+            _logger.info(f"Retrieving bucket list from {url}")
             response.raise_for_status()
         except HTTPError as ex:
             raise BucketFsError(
@@ -169,7 +173,7 @@ def buckets(self) -> MutableMapping[str, Bucket]:
     def __str__(self) -> str:
         return f"Service<{self._url}>"
 
-    def __iter__(self) -> Iterator[Bucket]:
+    def __iter__(self) -> Iterator[str]:
         yield from self.buckets
 
     def __getitem__(self, item: str) -> Bucket:
@@ -222,6 +226,7 @@ def _auth(self) -> HTTPBasicAuth:
     @property
     def files(self) -> Iterable[str]:
         url = _build_url(service_url=self._service, bucket=self.name)
+        _logger.info(f"Retrieving bucket listing for {self.name}.")
         response = requests.get(url, auth=self._auth, verify=self._verify)
         try:
             response.raise_for_status()
@@ -245,6 +250,7 @@ def upload(
             data: raw content of the file.
         """
         url = _build_url(service_url=self._service, bucket=self.name, path=path)
+        _logger.info(f"Uploading {path} to bucket {self.name}.")
         response = requests.put(url, data=data, auth=self._auth, verify=self._verify)
         try:
             response.raise_for_status()
@@ -262,6 +268,7 @@ def delete(self, path) -> None:
             A BucketFsError if the operation couldn't be executed successfully.
         """
         url = _build_url(service_url=self._service, bucket=self.name, path=path)
+        _logger.info(f"Deleting {path} from bucket {self.name}.")
         response = requests.delete(url, auth=self._auth, verify=self._verify)
         try:
             response.raise_for_status()
@@ -280,6 +287,9 @@ def download(self, path: str, chunk_size: int = 8192) -> Iterable[ByteString]:
             An iterable of binary chunks representing the downloaded file.
         """
         url = _build_url(service_url=self._service, bucket=self.name, path=path)
+        _logger.info(
+            f"Downloading {path} using a chunk size of {chunk_size} bytes from bucket {self.name}."
+        )
         with requests.get(
             url, stream=True, auth=self._auth, verify=self._verify
         ) as response: