Add sidekiq-cron patch for automatic monitoring of jobs listed in the

schedule

* optional patch under `sidekiq_cron`
* patch the `Sidekiq::Cron::Job#save` method and auto inject the
  Sentry::MonitorCheckIns module and turn monitoring on

part of #2134

CHANGELOG.md

@@ -3,6 +3,14 @@
 ### Features
 
 - Improve default slug generation for Crons [#2168](https://github.com/getsentry/sentry-ruby/pull/2168)
+- Automatic Crons support for scheduling gems
+  - Add support for `sidekiq-cron` [#2170](https://github.com/getsentry/sentry-ruby/pull/2170)
+
+  You can opt in to the `sidekiq-cron` patch and we will automatically monitor check-ins for all jobs listed in your `config/schedule.yml` file.
+
+  ```rb
+  config.enabled_patches += [:sidekiq_cron]
+  ```
 
 ### Bug Fixes
 

sentry-sidekiq/Gemfile

@@ -23,6 +23,7 @@ sidekiq_version = "7.0" if sidekiq_version.nil?
 sidekiq_version = Gem::Version.new(sidekiq_version)
 
 gem "sidekiq", "~> #{sidekiq_version}"
+gem "sidekiq-cron" if sidekiq_version >= Gem::Version.new("6.0")
 
 gem "rails", "> 5.0.0", "< 7.1.0"
 

sentry-sidekiq/lib/sentry-sidekiq.rb

@@ -39,3 +39,6 @@ class Railtie < ::Rails::Railtie
     chain.add Sentry::Sidekiq::SentryContextClientMiddleware
   end
 end
+
+# patches
+require "sentry/sidekiq/cron/job"

sentry-sidekiq/lib/sentry/sidekiq/cron/job.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+return unless defined?(::Sidekiq::Cron::Job)
+
+module Sentry
+  module Sidekiq
+    module Cron
+      module Job
+        def save
+          # validation failed, do nothing
+          return false unless super
+
+          # fail gracefully if can't find class
+          klass_const =
+            begin
+              ::Sidekiq::Cron::Support.constantize(klass.to_s)
+            rescue NameError
+              return true
+            end
+
+          # only patch if not explicitly included in job by user
+          unless klass_const.send(:ancestors).include?(Sentry::Cron::MonitorCheckIns)
+            klass_const.send(:include, Sentry::Cron::MonitorCheckIns)
+            klass_const.send(:sentry_monitor_check_ins,
+                             slug: name,
+                             monitor_config: Sentry::Cron::MonitorConfig.from_crontab(cron))
+          end
+        end
+      end
+    end
+  end
+end
+
+Sentry.register_patch(:sidekiq_cron, Sentry::Sidekiq::Cron::Job, ::Sidekiq::Cron::Job)

sentry-sidekiq/spec/fixtures/schedule.yml

@@ -0,0 +1,11 @@
+happy:
+  cron: "* * * * *"
+  class: "HappyWorker"
+
+manual:
+  cron: "* * * * *"
+  class: "SadWorkerWithCron"
+
+invalid_cron:
+  cron: "not a crontab"
+  class: "ReportingWorker"

sentry-sidekiq/spec/sentry/sidekiq/cron/job_spec.rb

@@ -0,0 +1,46 @@
+require 'spec_helper'
+
+return unless defined?(Sidekiq::Cron::Job)
+
+RSpec.describe Sentry::Sidekiq::Cron::Job do
+  before do
+    perform_basic_setup { |c| c.enabled_patches += [:sidekiq_cron] }
+  end
+
+  before do
+    schedule_file = 'spec/fixtures/schedule.yml'
+    schedule = Sidekiq::Cron::Support.load_yaml(ERB.new(IO.read(schedule_file)).result)
+    Sidekiq::Cron::Job.load_from_hash!(schedule, source: 'schedule')
+  end
+
+  it 'patches class' do
+    expect(Sidekiq::Cron::Job.ancestors).to include(described_class)
+  end
+
+  it 'patches HappyWorker' do
+    expect(HappyWorker.ancestors).to include(Sentry::Cron::MonitorCheckIns)
+    expect(HappyWorker.sentry_monitor_slug).to eq('happy')
+    expect(HappyWorker.sentry_monitor_config).to be_a(Sentry::Cron::MonitorConfig)
+    expect(HappyWorker.sentry_monitor_config.schedule).to be_a(Sentry::Cron::MonitorSchedule::Crontab)
+    expect(HappyWorker.sentry_monitor_config.schedule.value).to eq('* * * * *')
+  end
+
+  it 'does not override SadWorkerWithCron manually set values' do
+    expect(SadWorkerWithCron.ancestors).to include(Sentry::Cron::MonitorCheckIns)
+    expect(SadWorkerWithCron.sentry_monitor_slug).to eq('failed_job')
+    expect(SadWorkerWithCron.sentry_monitor_config).to be_a(Sentry::Cron::MonitorConfig)
+    expect(SadWorkerWithCron.sentry_monitor_config.schedule).to be_a(Sentry::Cron::MonitorSchedule::Crontab)
+    expect(SadWorkerWithCron.sentry_monitor_config.schedule.value).to eq('5 * * * *')
+  end
+
+  it 'does not patch ReportingWorker because of invalid schedule' do
+    expect(ReportingWorker.ancestors).not_to include(Sentry::Cron::MonitorSchedule)
+  end
+
+  it 'does not raise error on invalid class' do
+    expect do
+      Sidekiq::Cron::Job.create(name: 'invalid_class', cron: '* * * * *', class: 'UndefinedClass')
+    end.not_to raise_error
+  end
+
+end

sentry-sidekiq/spec/spec_helper.rb

@@ -8,9 +8,8 @@
 WITH_SIDEKIQ_7 = Gem::Version.new(Sidekiq::VERSION) >= Gem::Version.new("7.0")
 WITH_SIDEKIQ_6 = Gem::Version.new(Sidekiq::VERSION) >= Gem::Version.new("6.0") && !WITH_SIDEKIQ_7
 
-if WITH_SIDEKIQ_7
-  require "sidekiq/embedded"
-end
+require "sidekiq/embedded" if WITH_SIDEKIQ_7
+require 'sidekiq-cron' if WITH_SIDEKIQ_6 || WITH_SIDEKIQ_7
 
 require "sentry-ruby"