Previously, a user avatar redirect had a lifetime of 24h. That means that a change to the S3 CDN URL would take up to 24h to propagate to clients and intermediate CDNs.
This commit reduces the max age to 1 hour, but also introduces a `stale-while-revalidate` directive. This allows clients and CDNs to use a 'stale' value if it was received between 1h and 24h ago, as long as they make a background request to update the cache. This should reduce the impact of S3 URL changes. 1 hour after the change, the CDN will start serving updated values. Plus, if users have cached bad responses, their browser will automatically fetch the correct version and use it on the next page load.
In "GlobalSetting.redirect_avatar_requests" mode, when the application gets
an avatar request it returns a "redirect" to the S3 CDN.
This shields the application from caching avatars and downloading from S3.
However clients will make 2 requests per avatar. (one to get redirect,
second to get avatar)
A one hour cache on a redirect means there may be an increase in CDN
traffic, given more clients will ask for the redirect every hour.
This may also lead to an increase in origin requests to the application.
To mitigate lets cache the CDN URL for 1 day.
The downside is that any changes to S3 CDN need extra care to allow for
the extra 1 day delay. (leave data around for 1 extra day)
When uploads are stored on S3, by default Discourse will fetch the avatars and proxy them through to the requesting client. This is simple, but it can lead to significant inbound/outbound network load in the hosting environment.
This commit adds an optional redirect_avatar_requests GlobalSetting. When enabled, requests for user avatars will be redirected to the S3 asset instead of being proxied. This adds an extra round-trip for clients, but it should significantly reduce server load. To mitigate that extra round-trip for clients, a CDN with 'follow redirect' capability could be used.
* File.exists? is deprecated and removed in Ruby 3.2 in favor of
File.exist?
* Dir.exists? is deprecated and removed in Ruby 3.2 in favor of
Dir.exist?
This reverts commit e3de45359f.
We need to improve out strategy by adding a cache breaker with this change ... some assets on CDNs and clients may have incorrect CORS headers which can cause stuff to break.
Dependency on gifsicle, allow_animated_avatars and allow_animated_thumbnails
site settings were all removed. Animated GIF images are still allowed, but
the generated optimized images are no longer animated for those (which were
used for avatars and thumbnails).
The added 'animated' is populated by extracting information using FastImage.
This field was used to selectively reoptimize old animations. This process
happens in the background.
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
Co-authored-by: Sam Saffron <sam.saffron@gmail.com>
Co-authored-by: David Taylor <david@taylorhq.com>
This gives more control over the request. In particular we can easily
lookup DNS dynamically, instead of only upon NGINX startup.
Previously, NGINX was looking up IP for the letter avatar service and
caching the CDN IP address, this caused issues if CDN changed IP, in
which letter avatars would be broken till a container restarted.
NGINX config has been updated to add caching. This change will require
a container rebuild.
The proxy will now function in development environments, so the patch
for `letter_avatar_proxy` has been removed.
Previously we killed caching on old avatars cause we kept serving blank
this meant we would front many more avatar requests after a version change
This change ensures all old avatars do not cause a flood of requests on the
server
We regressed and optimized images no longer worked with svg
The following adds the correct logic to simply copy file for svgs
and bypasses resizing for svg avatars
In some cases Akami was holding tight to these invalid avatars,
to avoid this happening we explain the avatar image is ancient
then when a new upload is added it automatically is older than
this.
