Release note for #5296

CHANGELOG.txt

@@ -18,6 +18,7 @@ Changelog
  * Increase delay before search in the snippet chooser, to prevent redundant search request round trips (Robert Rollins)
  * Add `WAGTAIL_EMAIL_MANAGEMENT_ENABLED` setting to determine whether users can change their email address (Janne Alatalo)
  * Recognise Soundcloud artist URLs as embeddable (Kiril Staikov)
+ * Add `WAGTAILDOCS_SERVE_METHOD` setting to determine how document downloads will be linked to and served (Tobias McNulty, Matt Westcott)
  * Fix: Added line breaks to long filenames on multiple image / document uploader (Kevin Howbrook)
  * Fix: Added https support for Scribd oEmbed provider (Rodrigo)
  * Fix: Changed StreamField group labels color so labels are visible (Catherine Farman)

docs/releases/2.7.rst

@@ -37,6 +37,7 @@ Other features
  * Increase delay before search in the snippet chooser, to prevent redundant search request round trips (Robert Rollins)
  * Add ``WAGTAIL_EMAIL_MANAGEMENT_ENABLED`` setting to determine whether users can change their email address (Janne Alatalo)
  * Recognise Soundcloud artist URLs as embeddable (Kiril Staikov)
+ * Add ``WAGTAILDOCS_SERVE_METHOD`` setting to determine how document downloads will be linked to and served (Tobias McNulty, Matt Westcott)
 
 
 Bug fixes
@@ -71,6 +72,14 @@ Upgrade considerations
 The internal ``Page.dummy_request`` method (which generates an HTTP request object simulating a real page request, for use in previews) has been deprecated, as it did not correctly handle errors generated during middleware processing. Any code that calls this method to render page previews should be updated to use the new method ``Page.make_preview_request(original_request=None, preview_mode=None)``, which builds the request and calls ``Page.serve_preview`` as a single operation.
 
 
+Changes to document serving on remote storage backends (Amazon S3 etc)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+This release introduces a new setting :ref:`WAGTAILDOCS_SERVE_METHOD <wagtaildocs_serve_method>` to control how document downloads are served. On previous versions of Wagtail, document files would always be served through a Django view, to allow permission checks to be applied. When using a remote storage backend such as Amazon S3, this meant that the document would be downloaded to the Django server on every download request.
+
+In Wagtail 2.7, the default behaviour on remote storage backends is to redirect to the storage's underlying URL after performing the permission check. If this is unsuitable for your project (for example, your storage provider is configured to block public access, or revealing its URL would be a security risk) you can revert to the previous behaviour by setting ``WAGTAILDOCS_SERVE_METHOD`` to ``'serve_view'``.
+
+
 ``wagtail.admin.utils`` and ``wagtail.admin.decorators`` modules deprecated
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~