A new table is created to track which path_id attachments are images,
and for those their metadata, and which thumbnails have been created.
Using path_id as the effective primary key lets us ignore if the
attachment is archived or not, saving some foreign key messes.
A new worker is added to observe events when rows are added to this
table, and to generate and store thumbnails for those images in
differing sizes and formats.
Hash the salt, user-id, and now avatar version into the filename.
This allows the URL contents to be immutable, and thus to be marked as
immutable and cacheable. Since avatars are served unauthenticated,
hashing with a server-side salt makes the current and past avatars not
enumerable.
This requires plumbing the current (or future) avatar version through
various parts of the upload process.
Since this already requires a full migration of current avatars, also
take the opportunity to fix the missing `.png` on S3 uploads (#12852).
We switch from SHA-1 to SHA-256, but truncate it such that avatar URL
data does not substantially increase in size.
Fixes: #12852.
We add `Content-Disposition: inline` header to commonly supported
video MIME types so that when we `Open` them in lightbox, they
play in new tab.
This will require a follow-up database migration to apply to
previously uploaded videos.
Use the built-in HTML escaping of Markup("…{var}…").format(), in order
to allow Semgrep to detect mistakes like Markup("…{var}…".format())
and Markup(f"…{var}…").
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Actions like deleting realms may leave unreferenced uploads in the
attachment storage backend.
Fix these by walking the complete contents of the attachment storage
backend, and removing files which are no longer present in the
database. This may take quite some time, as it is necessarily O(n) in
the number of files uploaded to the system.