Avoid silently changing settings; raise ImproperlyConfigured instead

storages/backends/gcloud.py

@@ -8,7 +8,7 @@
 from django.utils.deconstruct import deconstructible
 from django.utils.encoding import force_bytes, smart_str
 
-from storages.utils import clean_name, safe_join, setting
+from storages.utils import check_location, clean_name, safe_join, setting
 
 try:
     from google.cloud.storage.client import Client
@@ -101,7 +101,8 @@ def __init__(self, **settings):
             if hasattr(self, name):
                 setattr(self, name, value)
 
-        self.location = (self.location or '').lstrip('/')
+        check_location(self)
+
         self._bucket = None
         self._client = None
 

storages/backends/s3boto.py

@@ -14,7 +14,7 @@
 )
 from django.utils.six import BytesIO
 
-from storages.utils import clean_name, safe_join, setting
+from storages.utils import check_location, clean_name, safe_join, setting
 
 try:
     from boto import __version__ as boto_version
@@ -235,7 +235,8 @@ def __init__(self, acl=None, bucket=None, **settings):
         if bucket is not None:
             self.bucket_name = bucket
 
-        self.location = (self.location or '').lstrip('/')
+        check_location(self)
+
         # Backward-compatibility: given the anteriority of the SECURE_URL setting
         # we fall back to https if specified in order to avoid the construction
         # of unsecure urls.

storages/backends/s3boto3.py

@@ -16,7 +16,7 @@
 from django.utils.six.moves.urllib import parse as urlparse
 from django.utils.timezone import is_naive, localtime
 
-from storages.utils import safe_join, setting
+from storages.utils import check_location, safe_join, setting
 
 try:
     import boto3.session
@@ -237,7 +237,8 @@ def __init__(self, acl=None, bucket=None, **settings):
         if bucket is not None:
             self.bucket_name = bucket
 
-        self.location = (self.location or '').lstrip('/')
+        check_location(self)
+
         # Backward-compatibility: given the anteriority of the SECURE_URL setting
         # we fall back to https if specified in order to avoid the construction
         # of unsecure urls.

storages/utils.py

@@ -80,3 +80,15 @@ def safe_join(base, *paths):
                          ' component')
 
     return final_path.lstrip('/')
+
+
+def check_location(storage):
+    if storage.location.startswith('/'):
+        correct = storage.location.lstrip('/')
+        raise ImproperlyConfigured(
+            "%s.location cannot begin with a leading slash. Found '%s'. Use '%s' instead." % (
+                storage.__class__.__name__,
+                storage.location,
+                correct,
+            )
+        )

tests/test_gcloud.py

@@ -8,6 +8,7 @@
 import datetime
 import mimetypes
 
+from django.core.exceptions import ImproperlyConfigured
 from django.core.files.base import ContentFile
 from django.test import TestCase
 from django.utils import timezone
@@ -359,3 +360,11 @@ def test_cache_control(self):
         bucket = self.storage.client.get_bucket(self.bucket_name)
         blob = bucket.get_blob(filename)
         self.assertEqual(blob.cache_control, cache_control)
+
+    def test_location_leading_slash(self):
+        msg = (
+            "GoogleCloudStorage.location cannot begin with a leading slash. "
+            "Found '/'. Use '' instead."
+        )
+        with self.assertRaises(ImproperlyConfigured, msg=msg):
+            gcloud.GoogleCloudStorage(location='/')

tests/test_gs.py

@@ -1,3 +1,4 @@
+from django.core.exceptions import ImproperlyConfigured
 from django.core.files.base import ContentFile
 from django.test import TestCase
 
@@ -30,3 +31,11 @@ def test_gs_gzip(self):
             policy=self.storage.default_acl,
             rewind=True,
         )
+
+    def test_location_leading_slash(self):
+        msg = (
+            "GSBotoStorage.location cannot begin with a leading slash. "
+            "Found '/'. Use '' instead."
+        )
+        with self.assertRaises(ImproperlyConfigured, msg=msg):
+            gs.GSBotoStorage(location='/')

tests/test_s3boto.py

@@ -9,6 +9,7 @@
 from boto.exception import S3ResponseError
 from boto.s3.key import Key
 from boto.utils import ISO8601, parse_ts
+from django.core.exceptions import ImproperlyConfigured
 from django.core.files.base import ContentFile
 from django.test import TestCase
 from django.utils import timezone as tz
@@ -343,3 +344,11 @@ def upload_part_from_file(fp, part_num, *args, **kwargs):
         f.close()
 
         assert content.size == sum(file_part_size)
+
+    def test_location_leading_slash(self):
+        msg = (
+            "S3BotoStorage.location cannot begin with a leading slash. "
+            "Found '/'. Use '' instead."
+        )
+        with self.assertRaises(ImproperlyConfigured, msg=msg):
+            s3boto.S3BotoStorage(location='/')

tests/test_s3boto3.py

@@ -8,6 +8,7 @@
 
 from botocore.exceptions import ClientError
 from django.conf import settings
+from django.core.exceptions import ImproperlyConfigured
 from django.core.files.base import ContentFile
 from django.test import TestCase
 from django.utils.six.moves.urllib import parse as urlparse
@@ -509,3 +510,11 @@ def test_file_write_after_exceeding_5mb(self):
                     'PartNumber': 2
                 }
             ]})
+
+    def test_location_leading_slash(self):
+        msg = (
+            "S3Boto3Storage.location cannot begin with a leading slash. "
+            "Found '/'. Use '' instead."
+        )
+        with self.assertRaises(ImproperlyConfigured, msg=msg):
+            s3boto3.S3Boto3Storage(location='/')