add hourly check for delayed job errors

app/logical/delayed_job_error_checker.rb

@@ -0,0 +1,20 @@
+#!/usr/bin/env ruby
+
+require 'mail'
+
+class DelayedJobErrorChecker
+  def check!
+    errors = Delayed::Job.where("last_error is not null").limit(100).pluck(:last_error).map {|x| x[0..100]}
+    if errors.size == 100
+      mail = Mail.new do
+        from "webmaster@danbooru.donmai.us"
+        to "r888888888@gmail.com"
+        subject "[danbooru] Delayed job error count at #{errors}"
+        body errors.uniq.join("\n")
+      end
+      mail.delivery_method :sendmail
+      mail.deliver
+    end
+  end
+end
+

config/schedule.rb

@@ -5,6 +5,10 @@ every 1.hour do
   runner "UploadErrorChecker.new.check!"
 end
 
+every 1.hour do
+  runner "DelayedJobErrorChecker.new.check!"
+end
+
 every 1.day do
   runner "DailyMaintenance.new.run"
 end