More robust PuSH subscription refreshes (#2799)

* Fix #2473 - Use sidekiq scheduler to refresh PuSH subscriptions instead of cron

Fix an issue where / in domain would raise exception in TagManager#normalize_domain

PuSH subscriptions refresh done in a round-robin way to avoid hammering a single
server's hub in sequence. Correct handling of failures/retries through Sidekiq (see
also #2613). Optimize Account#with_followers scope. Also, since subscriptions
are now delegated to Sidekiq jobs, an uncaught exception will not stop the entire
refreshing operation halfway through

Fix #2702 - Correct user agent header on outgoing http requests

* Add test for SubscribeService

* Extract #expiring_accounts into method

* Make mastodon:push:refresh no-op

* Queues are now defined in sidekiq.yml

* Queues are now in sidekiq.yml

1 files changed, 3 insertions, 2 deletions

diff --git a/app/models/account.rb b/app/models/account.rb
index d64591641..87b97a20d 100644
--- a/app/models/account.rb
+++ b/app/models/account.rb
@@ -103,9 +103,10 @@ class Account < ApplicationRecord
 
   scope :remote, -> { where.not(domain: nil) }
   scope :local, -> { where(domain: nil) }
-  scope :without_followers, -> { where('(select count(f.id) from follows as f where f.target_account_id = accounts.id) = 0') }
-  scope :with_followers, -> { where('(select count(f.id) from follows as f where f.target_account_id = accounts.id) > 0') }
+  scope :without_followers, -> { where(followers_count: 0) }
+  scope :with_followers, -> { where('followers_count > 0') }
   scope :expiring, ->(time) { where(subscription_expires_at: nil).or(where('subscription_expires_at < ?', time)).remote.with_followers }
+  scope :partitioned, -> { order('row_number() over (partition by domain)') }
   scope :silenced, -> { where(silenced: true) }
   scope :suspended, -> { where(suspended: true) }
   scope :recent, -> { reorder(id: :desc) }