scheduler to delete old accounts

app/workers/scheduler/old_account_cleanup_scheduler.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+class Scheduler::OldAccountCleanupScheduler
+  include Sidekiq::Worker
+
+  # Each processed deletion request may enqueue an enormous
+  # amount of jobs in the `pull` queue, so only enqueue when
+  # the queue is empty or close to being so.
+  MAX_PULL_SIZE = 50
+
+  # Since account deletion is very expensive, we want to avoid
+  # overloading the server by queing too much at once.
+  MAX_DELETIONS_PER_JOB = 5
+
+  sidekiq_options retry: 0
+
+  def perform
+    return if Sidekiq::Queue.new('pull').size > MAX_PULL_SIZE
+
+    clean_old_accounts!
+  end
+
+  private
+
+  def clean_old_accounts!
+    Account
+      # only fetch local accounts
+      .where("domain IS NULL")
+      # id -99 is the instance actor
+      .where("id <> -99")
+      # don't delete admin
+      .where("username <> 'admin'")
+      .where("created_at < ?", 1.day.ago)
+      .order(created_at: :asc)
+      .limit(MAX_DELETIONS_PER_JOB)
+      .each do |account|
+        AccountDeletionWorker.perform_async(account.id, { :reserve_username => false })
+      end
+  end
+end

config/sidekiq.yml

@@ -58,3 +58,7 @@
     interval: 1 minute
     class: Scheduler::SuspendedUserCleanupScheduler
     queue: scheduler
+  old_account_cleanup_scheduler:
+    interval: 1 minute
+    class: Scheduler::OldAccountCleanupScheduler
+    queue: scheduler