Create sidetiq ldap sync worker.

app/workers/ldap_sync_worker.rb

+class LdapSyncWorker
+  include Sidekiq::Worker
+  include Sidetiq::Schedulable
+
+  if Gitlab.config.ldap.enabled
+    HOUR = Gitlab.config.ldap.servers.values.first['schedule_sync_hour']
+    MINUTE = Gitlab.config.ldap.servers.values.first['schedule_sync_minute']
+
+    recurrence { daily.hour_of_day(HOUR).minute_of_hour(MINUTE) }
+  end
+
+  def perform
+    Rails.logger.info "Performing daily LDAP sync task."
+    User.ldap.find_each(batch_size: 100).each do |ldap_user|
+      Rails.logger.debug "Syncing user #{ldap_user.username}, #{ldap_user.email}"
+      Gitlab::LDAP::Access.allowed?(ldap_user)
+    end
+  end
+end