capture the current shard for jobs

including batch jobs

test plan:
 * n/a without a sharding implementation

Change-Id: Id4e8b8a72e71a21e0862fda27059f57412a80a53
Reviewed-on: https://gerrit.instructure.com/10165
Reviewed-by: Jon Jensen <jon@instructure.com>
Tested-by: Cody Cutrer <cody@instructure.com>

lib/stubs/shard.rb

@@ -49,6 +49,12 @@ class Shard
     {}
   end
 
+  yaml_as "tag:instructure.com,2012:Shard"
+
+  def self.yaml_new(klass, tag, val)
+    default
+  end
+
   module RSpec
     def self.included(klass)
       klass.before do

vendor/plugins/delayed_job/lib/delayed/backend/active_record.rb

@@ -19,6 +19,11 @@ module Delayed
       class Job < ::ActiveRecord::Base
         include Delayed::Backend::Base
         set_table_name :delayed_jobs
+        attr_writer :current_shard
+
+        def current_shard
+          @current_shard || Shard.default
+        end
 
         # be aware that some strand functionality is controlled by triggers on
         # the database. see

vendor/plugins/delayed_job/lib/delayed/backend/base.rb

@@ -33,6 +33,7 @@ module Delayed
           options[:payload_object] = object
           options[:queue] ||= Delayed::Worker.queue
           options[:max_attempts] ||= Delayed::Worker.max_attempts
+          options[:current_shard] = Shard.current
           if options[:singleton]
             options[:strand] = options.delete :singleton
             self.transaction do

vendor/plugins/delayed_job/spec_canvas/delayed_batch_spec.rb

@@ -1,4 +1,4 @@
-require File.expand_path("../spec_helper", __FILE__)
+require File.expand_path("../../../../../spec/sharding_spec_helper", __FILE__)
 
 describe Delayed::Batch do
   before :each do
@@ -69,4 +69,28 @@ describe Delayed::Batch do
       Delayed::Job.count.should == 2
     end
   end
+
+  shared_examples_for "delayed_jobs_shards" do
+    it "should keep track of the current shard on child jobs" do
+      shard = @shard1 || Shard.default
+      shard.activate do
+        Delayed::Batch.serial_batch {
+          "string".send_later(:size).should be_true
+          "string".send_later(:gsub, /./, "!").should be_true
+        }
+      end
+      job = Delayed::Job.last
+      job.current_shard.should == shard
+      job.payload_object.jobs.first.current_shard.should == shard
+    end
+  end
+
+  describe "current_shard" do
+    it_should_behave_like "delayed_jobs_shards"
+
+    context "sharding" do
+      it_should_behave_like "sharding"
+      it_should_behave_like "delayed_jobs_shards"
+    end
+  end
 end