From 950bc608c2380702d61c5752f9a032cbec0a297f Mon Sep 17 00:00:00 2001
From: evazion <noizave@gmail.com>
Date: Wed, 6 Oct 2021 04:14:23 -0500
Subject: [PATCH] maintenance: add job to check for database corruption.

Add a job to run pg_amcheck hourly to check for corrupt database indexes.

https://www.postgresql.org/docs/14/app-pgamcheck.html
---
 app/jobs/amcheck_database_job.rb       | 18 ++++++++++++++++++
 app/logical/danbooru_maintenance.rb    |  1 +
 test/jobs/amcheck_database_job_test.rb |  9 +++++++++
 3 files changed, 28 insertions(+)
 create mode 100644 app/jobs/amcheck_database_job.rb
 create mode 100644 test/jobs/amcheck_database_job_test.rb

diff --git a/app/jobs/amcheck_database_job.rb b/app/jobs/amcheck_database_job.rb
new file mode 100644
index 000000000..184b82ff3
--- /dev/null
+++ b/app/jobs/amcheck_database_job.rb
@@ -0,0 +1,18 @@
+# A job that runs hourly to check the database for corruption. Spawned by {DanbooruMaintenance}.
+# Requires at least PostgreSQL 14.0 to be installed for pg_amcheck to be available.
+#
+# https://www.postgresql.org/docs/14/app-pgamcheck.html
+class AmcheckDatabaseJob < ApplicationJob
+  def perform(options: "--verbose --install-missing --heapallindexed --parent-check")
+    return unless system("pg_amcheck --version")
+
+    connection_url = ApplicationRecord.connection_db_config.url
+    output = %x(PGDATABASE="#{connection_url}" pg_amcheck #{options})
+    notify(output) unless $?.success?
+  end
+
+  def notify(output)
+    DanbooruLogger.info(output)
+    Dmail.create_automated(to: User.owner, title: "pg_amcheck failed", body: output)
+  end
+end
diff --git a/app/logical/danbooru_maintenance.rb b/app/logical/danbooru_maintenance.rb
index d77fd9862..6bd12a5a2 100644
--- a/app/logical/danbooru_maintenance.rb
+++ b/app/logical/danbooru_maintenance.rb
@@ -6,6 +6,7 @@ module DanbooruMaintenance
     queue PrunePostsJob
     queue PruneRateLimitsJob
     queue RegeneratePostCountsJob
+    queue AmcheckDatabaseJob
   end
 
   def daily
diff --git a/test/jobs/amcheck_database_job_test.rb b/test/jobs/amcheck_database_job_test.rb
new file mode 100644
index 000000000..b806d8e22
--- /dev/null
+++ b/test/jobs/amcheck_database_job_test.rb
@@ -0,0 +1,9 @@
+require 'test_helper'
+
+class AmcheckDatabaseJobTest < ActiveJob::TestCase
+  context "AmcheckDatabaseJob" do
+    should "work" do
+      AmcheckDatabaseJob.perform_now
+    end
+  end
+end