mastodon/app/lib
ThibG ca56527140
Add follower synchronization mechanism (#14510)
* Add support for followers synchronization on the receiving end

Check the `collectionSynchronization` attribute on `Create` and `Announce`
activities and synchronize followers from provided collection if possible.

* Add tests for followers synchronization on the receiving end

* Add support for follower synchronization on the sender's end

* Add tests for the sending end

* Switch from AS attributes to HTTP header

Replace the custom `collectionSynchronization` ActivityStreams attribute by
an HTTP header (`X-AS-Collection-Synchronization`) with the same syntax as
the `Signature` header and the following fields:
- `collectionId` to specify which collection to synchronize
- `digest` for the SHA256 hex-digest of the list of followers known on the
   receiving instance (where “receiving instance” is determined by accounts
   sharing the same host name for their ActivityPub actor `id`)
- `url` of a collection that should be fetched by the instance actor

Internally, move away from the webfinger-based `domain` attribute and use
account `uri` prefix to group accounts.

* Add environment variable to disable followers synchronization

Since the whole mechanism relies on some new preconditions that, in some
extremely rare cases, might not be met, add an environment variable
(DISABLE_FOLLOWERS_SYNCHRONIZATION) to disable the mechanism altogether and
avoid followers being incorrectly removed.

The current conditions are:
1. all managed accounts' actor `id` and inbox URL have the same URI scheme and
   netloc.
2. all accounts whose actor `id` or inbox URL share the same URI scheme and
   netloc as a managed account must be managed by the same Mastodon instance
   as well.

As far as Mastodon is concerned, breaking those preconditions require extensive
configuration changes in the reverse proxy and might also cause other issues.

Therefore, this environment variable provides a way out for people with highly
unusual configurations, and can be safely ignored for the overwhelming majority
of Mastodon administrators.

* Only set follower synchronization header on non-public statuses

This is to avoid unnecessary computations and allow Follow-related
activities to be handled by the usual codepath instead of going through
the synchronization mechanism (otherwise, any Follow/Undo/Accept activity
would trigger the synchronization mechanism even if processing the activity
itself would be enough to re-introduce synchronization)

* Change how ActivityPub::SynchronizeFollowersService handles follow requests

If the remote lists a local follower which we only know has sent a follow
request, consider the follow request as accepted instead of sending an Undo.

* Integrate review feeback

- rename X-AS-Collection-Synchronization to Collection-Synchronization
- various minor refactoring and code style changes

* Only select required fields when computing followers_hash

* Use actor URI rather than webfinger domain in synchronization endpoint

* Change hash computation to be a XOR of individual hashes

Makes it much easier to be memory-efficient, and avoid sorting discrepancy issues.

* Marginally improve followers_hash computation speed

* Further improve hash computation performances by using pluck_each
2020-10-21 18:04:09 +02:00
..
activitypub Add follower synchronization mechanism (#14510) 2020-10-21 18:04:09 +02:00
connection_pool Add request pool to improve delivery performance (#10353) 2019-07-02 00:34:38 +02:00
nodeinfo Add a nodeinfo endpoint (#12002) 2019-09-29 21:31:51 +02:00
ostatus Remove Atom feeds and old URLs in the form of GET /:username/updates/:id (#11247) 2019-07-07 16:16:51 +02:00
proof_provider Fix rubocop warning (#14288) 2020-07-14 19:05:07 +02:00
rss Improve RSS entries for statuses (#13592) 2020-05-10 09:50:54 +02:00
settings Removed disabling comments for Style/MethodMissingSuper (#15014) 2020-10-20 09:13:39 +02:00
activity_tracker.rb Add a nodeinfo endpoint (#12002) 2019-09-29 21:31:51 +02:00
application_extension.rb Conditional validations no longer accept strings for if/unless (#3124) 2017-05-19 03:11:23 +02:00
delivery_failure_tracker.rb Change delivery failure tracking to work with hostnames instead of URLs (#13437) 2020-04-15 20:33:24 +02:00
entity_cache.rb Bump rubocop from 0.86.0 to 0.88.0 (#14412) 2020-09-01 03:04:00 +02:00
exceptions.rb Fix movie width and frame_rate returning nil (#14357) 2020-07-19 22:28:27 +02:00
extractor.rb Using double splat operator (#5859) 2017-12-06 11:41:57 +01:00
fast_geometry_parser.rb Fix avatar and header issues by using custom geometry detector (#6515) 2018-02-21 03:40:12 +01:00
fast_ip_map.rb Add IP-based rules (#14963) 2020-10-12 16:33:49 +02:00
feed_manager.rb Refactor feed manager (#14761) 2020-09-08 03:41:16 +02:00
formatter.rb Bump rubocop from 0.86.0 to 0.88.0 (#14412) 2020-09-01 03:04:00 +02:00
hash_object.rb Migrate from ledermann/rails-settings to rails-settings-cached which allows global settings 2017-01-12 20:46:24 +01:00
inline_renderer.rb Add E2EE API (#13820) 2020-06-02 19:24:53 +02:00
language_detector.rb Fix Thai being skipped from language detection (#13989) 2020-06-25 22:45:01 +02:00
potential_friendship_tracker.rb Create Redisable#redis (#9633) 2019-02-02 19:11:38 +01:00
proof_provider.rb Add Keybase integration (#10297) 2019-03-18 21:00:55 +01:00
rate_limiter.rb Add rate limit for reporting (#13390) 2020-04-05 14:40:08 +02:00
request_pool.rb Add request pool to improve delivery performance (#10353) 2019-07-02 00:34:38 +02:00
request.rb Add environment variable to allow requests to some private addresses (#14722) 2020-09-26 20:57:39 +02:00
response_with_limit.rb Fix remote files not using Content-Type header, streaming (#14184) 2020-06-30 23:58:02 +02:00
rss_builder.rb Add RSS feeds for end-users (#7259) 2018-04-25 02:10:02 +02:00
sanitize_config.rb Add support for Gemini urls (#15013) 2020-10-19 17:02:13 +02:00
search_query_parser.rb Fix accounts search by full/partial display name and others (#11580) 2019-08-16 13:00:30 +02:00
search_query_transformer.rb Fix error when searching for empty phrase (#12711) 2019-12-30 18:30:24 +01:00
sidekiq_error_handler.rb Bump rubocop from 0.86.0 to 0.88.0 (#14412) 2020-09-01 03:04:00 +02:00
spam_check.rb Exempt staff members from spam check (#12874) 2020-01-17 07:50:30 +01:00
status_filter.rb Fix n+1 queries in StatusThreadingConcern (#7321) 2018-05-03 10:41:58 +02:00
status_finder.rb Remove Atom feeds and old URLs in the form of GET /:username/updates/:id (#11247) 2019-07-07 16:16:51 +02:00
tag_manager.rb Refactor domain block checks (#11268) 2019-07-09 03:27:35 +02:00
themes.rb Add support for multiple themes (#4959) 2017-09-19 16:36:23 +02:00
toc_generator.rb Add fallback section ID with ToC (#11941) 2019-09-23 17:25:10 +02:00
user_settings_decorator.rb Add option to disable swiping motions across the WebUI (#13885) 2020-09-30 19:31:03 +02:00
webfinger_resource.rb Fix webfinger returning wrong status code on malformed or missing param (#13759) 2020-05-14 23:28:06 +02:00
webfinger.rb Remove dependency on goldfinger gem (#14919) 2020-10-08 00:34:57 +02:00