Trying to do a two-release migration proved to be very hacky and ugly.
Instead this is preparation for moving defaults first and then merging
the old configuration left in admin's config file at runtime while still
emitting a warning. This hopefully will be a lot nicer and less
complicated.
Elixir 1.19 started emitting warnings about our use of:
config :logger, :console and
config :logger, backends: []
which got split in 1.15 to :default_handler, :default_formatter, and
LoggerBackends.add(backend) respectively.
On Pleroma startup it is now necessary to add the additional logger
backends at runtime (done with configure_logger() in application.ex).
New config key :pleroma, :logger_backends: [] has replaced the older
backends array. The logger_backends package is now used to facilitate
usage of other logger backends besides the default one (:logger_std_h
from OTP).
Warnings were added to Pleroma startup to warn about the usage of
:logger, backends and additional logic was introduced to make addition
of ExSyslogger to admin's configuration less dumb.
Ref: https://hexdocs.pm/logger/1.15.0/Logger.html#module-backends-and-backwards-compatibility
This logic only exists in the Plug, so attempting to validate the signature by calling the library function HTTPSignature.validate_conn/2 directly will never work because we do not attempt to construct the (request-target) and @request-target headers with both the commonly misinterpreted and correct implementation of this field. Therefore all attempts to validate a signature from an Oban Job will fail.
Websites are increasingly getting more bloated with tricks like inlining content (e.g., CNN.com) which puts pages at or above 5MB. This value may still be too low.
Rich Media parsing was previously handled on-demand with a 2 second HTTP request timeout and retained only in Cachex. Every time a Pleroma instance is restarted it will have to request and parse the data for each status with a URL detected. When fetching a batch of statuses they were processed in parallel to attempt to keep the maximum latency at 2 seconds, but often resulted in a timeline appearing to hang during loading due to a URL that could not be successfully reached. URLs which had images links that expire (Amazon AWS) were parsed and inserted with a TTL to ensure the image link would not break.
Rich Media data is now cached in the database and fetched asynchronously. Cachex is used as a read-through cache. When the data becomes available we stream an update to the clients. If the result is returned quickly the experience is almost seamless. Activities were already processed for their Rich Media data during ingestion to warm the cache, so users should not normally encounter the asynchronous loading of the Rich Media data.
Implementation notes:
- The async worker is a Task with a globally unique process name to prevent duplicate processing of the same URL
- The Task will attempt to fetch the data 3 times with increasing sleep time between attempts
- The HTTP request obeys the default HTTP request timeout value instead of 2 seconds
- URLs that cannot be successfully parsed due to an unexpected error receives a negative cache entry for 15 minutes
- URLs that fail with an expected error will receive a negative cache with no TTL
- Activities that have no detected URLs insert a nil value in the Cachex :scrubber_cache so we do not repeat parsing the object content with Floki every time the activity is rendered
- Expiring image URLs are handled with an Oban job
- There is no automatic cleanup of the Rich Media data in the database, but it is safe to delete at any time
- The post draft/preview feature makes the URL processing synchronous so the rendered post preview will have an accurate rendering
Overall performance of timelines and creating new posts which contain URLs is greatly improved.
Old way was wrong for multiple reasons. If we do this as a config value it fixes :slave.start/3 being picked up as a compile warning on OTP26.
Also if we want to do any real clustering we'll need something like this to support OTP25 and older.
