mastodon/app/services
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
concerns Fix activity not being signed (#13948) 2020-06-03 08:33:30 +02:00
keys Add E2EE API (#13820) 2020-06-02 19:24:53 +02:00
account_search_service.rb Fix following restriction not working when exact match in account search (#14394) 2020-07-26 23:58:36 +02:00
after_block_domain_from_account_service.rb Fix account domain block not properly unfollowing accounts from domain (#14304) 2020-07-13 19:33:10 +02:00
after_block_service.rb Refactor feed manager (#14761) 2020-09-08 03:41:16 +02:00
after_unallow_domain_service.rb Change account suspensions to be reversible by default (#14726) 2020-09-15 14:37:58 +02:00
app_sign_up_service.rb Add IP-based rules (#14963) 2020-10-12 16:33:49 +02:00
authorize_follow_service.rb Remove Salmon and PubSubHubbub (#11205) 2019-07-06 23:26:16 +02:00
backup_service.rb Add E2EE API (#13820) 2020-06-02 19:24:53 +02:00
base_service.rb Remove unused AtomBuilderHelper (#1364) 2017-04-11 19:31:22 +02:00
batched_remove_status_service.rb Fix not publishing update of remote timeline (#13745) 2020-05-12 15:24:35 +02:00
block_domain_service.rb Change account suspensions to be reversible by default (#14726) 2020-09-15 14:37:58 +02:00
block_service.rb Fix BlockService trying to reject incorrect follow request (#11288) 2019-07-11 14:50:27 +02:00
bootstrap_timeline_service.rb Admin setting to disable default follows (#12566) 2019-12-16 23:55:50 +01:00
clear_domain_media_service.rb Make domain block/silence/reject-media code more robust (#13424) 2020-06-09 10:32:00 +02:00
delete_account_service.rb Change account suspensions to be reversible by default (#14726) 2020-09-15 14:37:58 +02:00
deliver_to_device_service.rb Add E2EE API (#13820) 2020-06-02 19:24:53 +02:00
fan_out_on_write_service.rb Change own direct-visibility statuses to be in the home feed again (#14711) 2020-09-01 13:30:42 +02:00
favourite_service.rb Add option to be notified when a followed user posts (#13546) 2020-09-18 17:26:45 +02:00
fetch_link_card_service.rb Bump rubocop from 0.86.0 to 0.88.0 (#14412) 2020-09-01 03:04:00 +02:00
fetch_oembed_service.rb Fix link crawler not specifying accepted content-type (#12646) 2019-12-18 16:56:06 +01:00
fetch_remote_status_service.rb Fix an error when ActivityPub::FetchRemoteStatusService url is called with nil (#12652) 2019-12-18 16:54:03 +01:00
fetch_resource_service.rb Fix not being able to resolve public resources in development environment (#13505) 2020-04-25 22:01:08 +02:00
follow_service.rb Add option to be notified when a followed user posts (#13546) 2020-09-18 17:26:45 +02:00
import_service.rb Add option to be notified when a followed user posts (#13546) 2020-09-18 17:26:45 +02:00
move_service.rb Fix account migration not affecting followers on origin server (#11980) 2019-09-29 16:23:13 +02:00
mute_service.rb Add duration parameter to muting. (#13831) 2020-10-13 01:01:14 +02:00
notify_service.rb Add option to be notified when a followed user posts (#13546) 2020-09-18 17:26:45 +02:00
post_status_service.rb Fix media not being marked sensitive when client sets a CW but no text (#13277) 2020-03-25 22:40:58 +01:00
precompute_feed_service.rb Refactor feed manager (#14761) 2020-09-08 03:41:16 +02:00
process_hashtags_service.rb Change hashtags to preserve first-used casing (#11416) 2019-07-28 05:59:51 +02:00
process_mentions_service.rb Remove dependency on goldfinger gem (#14919) 2020-10-08 00:34:57 +02:00
reblog_service.rb Add option to be notified when a followed user posts (#13546) 2020-09-18 17:26:45 +02:00
reject_follow_service.rb Remove Salmon and PubSubHubbub (#11205) 2019-07-06 23:26:16 +02:00
remove_status_service.rb Fix not publishing update of remote timeline (#13745) 2020-05-12 15:24:35 +02:00
report_service.rb Refactor all ActivityPub deliveries to be serialized and signed through one concern (#10966) 2019-06-04 23:11:18 +02:00
resolve_account_service.rb Remove dependency on goldfinger gem (#14919) 2020-10-08 00:34:57 +02:00
resolve_url_service.rb Fix some timeouts when searching URLs by limiting some database queries (#13253) 2020-03-12 23:06:43 +01:00
search_service.rb Fix hashtag search performing account search as well (#13758) 2020-05-14 23:37:37 +02:00
suspend_account_service.rb Change account suspensions to be reversible by default (#14726) 2020-09-15 14:37:58 +02:00
tag_search_service.rb Add exclude_unreviewed param to GET /api/v2/search REST API (#11977) 2019-09-28 01:02:21 +02:00
unallow_domain_service.rb Fix removing allowed domains being done synchronously (#14302) 2020-07-15 21:08:19 +02:00
unblock_domain_service.rb Add domain block notes (#11515) 2019-08-07 20:20:23 +02:00
unblock_service.rb Remove Salmon and PubSubHubbub (#11205) 2019-07-06 23:26:16 +02:00
unfavourite_service.rb Remove Salmon and PubSubHubbub (#11205) 2019-07-06 23:26:16 +02:00
unfollow_service.rb Fix Move handler queuing jobs that will fail if account is suspended (#11864) 2019-09-17 08:44:45 +02:00
unmute_service.rb Fix #231 - Muting 2017-03-02 18:49:32 +01:00
unsuspend_account_service.rb Change account suspensions to be reversible by default (#14726) 2020-09-15 14:37:58 +02:00
update_account_service.rb Bump rubocop from 0.86.0 to 0.88.0 (#14412) 2020-09-01 03:04:00 +02:00
verify_link_service.rb Rescue SSL error in verify link service (#9914) 2019-01-24 15:38:18 +01:00
vote_service.rb Fix invalid votes from the API being accepted (#12601) 2020-01-12 14:17:03 +01:00