This commit adds a new site setting "allowed_onebox_iframes". By default, all onebox iframes are allowed. When the list of domains is restricted, Onebox will automatically skip engines which require those domains, and use a fallback engine.
When linking to a topic in the same Discourse, we try to onebox the link to show the title
and other various information depending on whether it's a "standard" or "inline" onebox.
However, we were not properly detecting links to topics that had no slugs (eg. https://meta.discourse.org/t/1234).
Previously if somehow a user created a blank markdown document using tag
tricks (eg `<p></p><p></p><p></p><p></p><p></p><p></p>`) and so on, we would
completely strip the document down to blank on post process due to onebox
hack.
Needs a followup cause I am still unclear about the reason for empty p stripping
and it can cause some unclear cases when we re-cook posts.
For consistency this PR introduces using custom markdown and short upload:// URLs for video and audio uploads, rather than just treating them as links and relying on the oneboxer. The markdown syntax for videos is  and for audio it is .
This is achieved in discourse-markdown-it by modifying the rules for images in mardown-it via md.renderer.rules.image. We return HTML instead of the token when we encounter audio or video after | and the preview renders that HTML. Also when uploading an audio or video file we insert the relevant markdown into the composer.
We already cache failed onebox URL requests client-side, we now want to cache this on the server-side for extra protection. failed onebox previews will be cached for 1 hour, and any more requests for that URL will fail with a 404 status. Forcing a rebake via the Rebake HTML action will delete the failed URL cache (like how the oneboxer preview cache is deleted).
Discourse.cache is a more consistent method to use and offers clean fallback
if you are skipping redis
This is part of a larger change that both optimizes Discoruse.cache and omits
use of setex on $redis in favor of consistently using discourse cache
Bench does reveal that use of Rails.cache and Discourse.cache is 1.25x slower
than redis.setex / get so a re-implementation will follow prior to porting
This PR introduces a new secure media setting. When enabled, it prevent unathorized access to media uploads (files of type image, video and audio). When the `login_required` setting is enabled, then all media uploads will be protected from unauthorized (anonymous) access. When `login_required`is disabled, only media in private messages will be protected from unauthorized access.
A few notes:
- the `prevent_anons_from_downloading_files` setting no longer applies to audio and video uploads
- the `secure_media` setting can only be enabled if S3 uploads are already enabled and configured
- upload records have a new column, `secure`, which is a boolean `true/false` of the upload's secure status
- when creating a public post with an upload that has already been uploaded and is marked as secure, the post creator will raise an error
- when enabling or disabling the setting on a site with existing uploads, the rake task `uploads:ensure_correct_acl` should be used to update all uploads' secure status and their ACL on S3
Zeitwerk simplifies working with dependencies in dev and makes it easier reloading class chains.
We no longer need to use Rails "require_dependency" anywhere and instead can just use standard
Ruby patterns to require files.
This is a far reaching change and we expect some followups here.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
Previously, the site setting was only effective on the client side of
things. Once the site setting was been reached, all oneboxes are not
rendered. This commit changes it such that the site setting is respected
both on the client and server side. The first N oneboxes are rendered and
once the limit has been reached, subsequent oneboxes will not be
rendered.
