This is only `text/plain`, currently. In such cases where the
client-provided content-type also does not specify a `charset`, we use
`chardet` to make a guess, and store that guess to provide later when
serving the content. The detection is done in a streaming fashion,
and thus should not require re-downloading the full content.
The tusd protocol allows DELETE requests ("terminations") at any
point, including after a file has successfully been uploaded. This
can allow tusd to remove a file from the bucket, out from under Zulip.
We use the new-in-2.7.0 pre-terminate hook to look up the file which
the client is requesting to terminate, and reject the termination if
it is a file that the Zulip database is already aware of.
These files are necessary for the protocol to verify that the file
upload was completed successfully. Rather than delete them, we update
their StorageClass if it is non-STANDARD.
The Content-Type, Content-Disposition, StorageClass, and general
metadata are not set according to our patterns by tusd; copy the file
to itself to update those properties.
Currently, it handles two hook types: 'pre-create' (to verify that the
user is authenticated and the file size is within the limit) and
'pre-finish' (which creates an attachment row).
No secret is shared between Django and tusd for authentication of the
hooks endpoints, because none is necessary -- tusd forwards the
end-user's credentials, and the hook checks them like it would any
end-user request. An end-user gaining access to the endpoint would be
able to do no more harm than via tusd or the normal file upload API.
Regardless, the previous commit has restricted access to the endpoint
at the nginx layer.
Co-authored-by: Brijmohan Siyag <brijsiyag@gmail.com>
